Sergej Ostojic

• Todorovic, Nikola; Andjelic, Bogdan; Nedeljkovic, David & Ostojic, Sergej (2026). The game of chess: Future directions for sports nutrition and supplementation. Nutrition and Health. ISSN 0260-1060. 32(5), p. 1429–1435. doi: 10.1177/02601060261447179. Full text in Research Archive Show summary

  Competitive chess is a cognitively intensive sport that demands sustained executive control, complex visuospatial processing, prolonged attention, and effective regulation of psychological stress under time pressure. Despite growing professionalization, research on nutritional strategies to support chess performance remains limited. Existing work has largely emphasized pharmacological cognitive enhancers, which offer limited ecological validity and raise ethical and regulatory concerns, while comparatively little attention has been paid to safe, non-prohibited interventions applicable to real-world competition. This paper synthesizes evidence on the neurocognitive and psychophysiological demands of competitive chess and identifies priorities for future nutrition and supplementation research. Drawing on mechanistic and translational insights from cognitive neuroscience and esports, we evaluate dietary supplements with potential to support cerebral bioenergetics, attentional stability, and stress modulation. Finally, we propose a structured, ecologically grounded research framework to guide evidence-based, ethically compliant performance optimization in chess.

• Grasaas, Erik; Sandbakk, Øyvind Bucher; Grasaas, Christina Åsan & Ostojic, Sergej (2026). Sport engagement and life satisfaction in late childhood: a population-based analysis. Frontiers in Sports and Active Living. 8. doi: 10.3389/fspor.2026.1784535. Full text in Research Archive Show summary

  Background: While sport participation and physical activity are widely recognized as beneficial for children's well-being, limited research has examined how the frequency of sport engagement relates to life satisfaction (LS) in late childhood. This study aimed to (1) describe the frequency of sport participation, active transport, and LS among Norwegian children aged 10–12 years, and (2) assess the associations between sport participation frequency, active transport mode, and LS, with attention to gender differences.Methods: Cross-sectional data were drawn from the 2024 Norwegian Ungdata Junior Survey, comprising 46,941 children aged 10–12 years. Participants completed an electronic questionnaire during school hours. Linear regression models were used to examine associations between sport participation frequency, transport mode, and LS (measured on a 0–10 scale), adjusting for socioeconomic status, grade level, and centrality, and stratified by gender.Results: Boys reported significantly higher LS than girls (mean 8.4 vs. 7.7, p < 0.01). Among boys, LS increased with sport participation frequency, from 8.0 (no evenings) to 8.6 (five evenings per week). In contrast, girls' LS remained relatively stable across participation levels (7.7–7.8). Regression analysis showed the strongest positive associations with LS observed for children participating in organized sports one to three evenings per week. No significant associations were found between type of transport and LS for either gender.Conclusions: In a large sample of representative Norwegian children aged 10–12 years of age, LS scores for boys progressed by the frequency of weekly sport participation but remained stable for girls. Still, the strongest positive associations between sport participation and LS were among those engaging in sports one to three sessions per week, which suggests that a balanced approach to youth sports, emphasizing enjoyment, autonomy, and social connection, may be more effective in promoting well-being than maximizing participation frequency in late childhood.

• Grasaas, Erik; Ostojic, Sergej; Stea, Tonje Holte & Sandbakk, Øyvind Bucher (2026). Prior-night sleep duration and the relationship to quality of life and educational context in Norwegian pre-adolescents. BMC Pediatrics. 26. doi: 10.1186/s12887-026-06830-6. Full text in Research Archive Show summary

  Sufficient sleep is associated with improved development, health, and quality of life (QoL). The aim of this paper is twofold: (1) to describe prior-night sleep duration according to sleep recommendations across socioeconomic status (SES), age, gender and screen time use among Norwegian pre-adolescents and (2) to explore the association between reported prior-night sleep duration with QoL and school factors stratified by gender. Cross-sectional data was aggregated from the Norwegian Ungdata Junior Survey, collected in 2024. In total, 45,185 children aged between 10 and 12 years provided self-reported data anonymously by filling out an electronic/online questionnaire during school hours. About half of the study sample (53.1%) reported adherence to international sleep recommendations for children aged 10 to 12 years, with somewhat higher adherence among boys than girls(54.5% vs. 51.8%, p &lt; 0.01). Results from binary regressions revealed positive associations related to QoL and school factors among children adhering to sleep recommendations compared to ones not adhering, with adjusted odds ratio ranging from 1.33 to 1.79 (all p &lt; 0.01). In this population-based sample of Norwegian children aged 10 to 12 years, approximately half reported not achieving the recommended 9 to 12 h of sleep per night. Reporting prior-night sleep duration in accordance to the international sleep recommendations were strongly associated with higher QoL and positive school related factors among boys and girls, but particularly strong among girls. These findings emphasize the vital role of adequate sleep among pre-adolescents for QoL and optimizing school contexts, offering valuable insight for future practice and policy. 1. Why is this study needed? Children aged 10 to 12 years are recommended to obtain 9 to 12&nbsp;h of sleep per day to support optimal health and development. However, global evidence indicates that between one-third to one-half of children report failing to meet these recommendations. 2. What is the key problem/issue/question this manuscript addresses? The aims of this paper were twofold: (1) to describe prior-night sleep duration according to the sleep recommendation across age, socioeconomic levels, gender and screen time use among Norwegian children aged 10 to 12 years and (2) to explore the association between reported prior-night sleep duration with quality of life and school factors stratified by gender. 3. What is the main point of your study? Research specifically examining sleep adherence and quality of life in Norwegian pre-adolescents is scarce. This study addresses that gap by providing novel data from a large population-based Norwegian sample, offering insight into potential cultural and age-specific differences. 4. What are your main results and what do they mean? This research identifies associations between children’s prior-night sleep duration and indicators of quality of life in an educational context, offering insights that may inform practice and policy development by highlighting the potential importance of sleep for daily functioning and well-being among children in Norway.

• Milanović, Sanja Musić; Križan, Helena; Šlaus, Nika; Brađašević, Emanuel; Morović, Maja Lang & Djordjic, Visnja [Show all 10 contributors for this article] (2026). Association Between Sub-National Regional Socioeconomic Status and Childhood Obesity in Five South-East European Countries: The WHO European Childhood Obesity Surveillance Initiative—COSI (2019). Children. 13(2). doi: 10.3390/children13020267. Full text in Research Archive Show summary

  Background/Objectives: This study focused on the sub-national regional heterogeneity in childhood obesity prevalence across five countries in south-east Europe and the correlation between this heterogeneity and socioeconomic differences. Previous studies have mainly observed national or cross-national data but this study used a sub-national regional approach that may be beneficial in the further investigation of childhood obesity. Methods: Nationally representative samples of children from Croatia, Montenegro, North Macedonia, Serbia and Slovenia were selected using the COSI methodology and used to estimate regional childhood obesity prevalence values. The Sub-national Human Development Database provided data on the Sub-national Human Development Index (SHDI). The spatial autocorrelation analysis of childhood obesity prevalence in sub-national regions was performed and its association with sub-national human development was tested with an ordinary least squares regression model. Results: This study found statistically significant differences in childhood obesity prevalence across sub-national regions in Croatia, Slovenia and Serbia, while no such differences were observed in North Macedonia and Montenegro. There was moderate clustering in childhood obesity rates (Moran’s I = 0.337). The results indicated a significant negative association between SHDI and childhood obesity prevalence across the 48 regions (β = −66.63, p < 0.001). Conclusions: Future public health efforts should take into consideration regional differences in childhood obesity prevalence, and more targeted research is essential for understanding the mechanisms of resilience and vulnerability on a sub-national level.

• Nedeljkovic, David; Todorovic, Nikola; Javorac, Dejan; Baltic, Sonja; Vranes, Milan & Panic, Jovana [Show all 14 contributors for this article] (2025). The effects of 8-week creatine supplementation with and without ubiquinol on sperm quality biomarkers in normospermic and oligospermic men: A randomized controlled pilot trial. Nutrition and Health. ISSN 0260-1060. doi: 10.1177/02601060251385000. Full text in Research Archive Show summary

  Background: No studies have investigated whether dietary creatine, administered alone or in the combination with other nutrients, can induce changes in the physical-chemical and microscopic characteristics of human semen. Objectives The primary objective of this randomized placebo-controlled exploratory pilot trial was to assess the effects of an 8-week supplementation regimen consisting of creatine, both with and without ubiquinol, on sperm quality in men classified as normospermic and oligospermic. Methods: A total of 15 volunteers (mean age 25.0 ± 6.1 years, body mass index 25.1 ± 2.0 kg/m²; including five oligospermic individuals) were randomly assigned, received the intended treatment, and were evaluated for spermiogram parameters, sperm biochemical markers, the World Health Organization (WHO-5) well-being index questionnaire, and the prevalence and severity of side effects. Results: There was a non-significant trend towards an increase in sperm concentration among participants receiving creatine-plus-ubiquinol, with an average rise of 7.4 million per milliliter ( P  = 0.22). Six out of ten participants receiving creatine (60%), both with and without ubiquinol, showed an improvement in sperm concentration at the 8-week follow-up, compared to only 20% of participants in the control group ( P  ≤ 0.05). In addition, all oligospermic men who received creatine and creatine-plus-ubiquinol demonstrated an improvement in sperm concentration at follow-up, whereas sperm concentration remained unchanged or further decreased among oligospermic men in the control group ( P  ≤ 0.05). Furthermore, there was a significant increase in sperm creatine concentration in the creatine-plus-ubiquinol group ( P = 0.03), demonstrating an average rise of 125.4 µmol/L (35.8%) at the 8-week follow-up. Conclusion: These preliminary findings are of considerable interest for male fertility health; however, they require validation through well-designed longitudinal trials with larger sample sizes. The study is registered at ClinicalTrials.gov (NCT06202469).

• Todorovic, Nikola; Ranisavljev, Marijana; Korovljev, Darinka; Mauti, Joy; Neumann, Christine & Mboya, Innocent [Show all 14 contributors for this article] (2025). Promoting Adolescent and Youth Health Through Physical Activity Initiatives and Interventions in Sub-Saharan Africa: The ARISE-NUTRINT and DASH Initiatives. International Journal of Public Health. ISSN 1661-8556. 70. doi: 10.3389/ijph.2025.1608609. Full text in Research Archive Show summary

  Regular physical activity (PA) is essential for maintaining health and wellbeing across all life stages, particularly in children and adolescents. Despite its benefits, most adolescents fail to meet the World Health Organization’s PA recommendations, with global trends indicating alarmingly low participation rates, particularly among girls. This issue is pronounced in Sub-Saharan Africa (SSA), where physical inactivity is a significant public health concern, contributing to rising obesity rates. Environmental, socio-economic, and cultural barriers further exacerbate low PA engagement, including extreme weather conditions, lack of recreational infrastructure, gender norms, and economic constraints. Addressing these challenges requires targeted interventions, including education, improved infrastructure, and policy implementation. Innovative programs such as ARISE-NUTRINT and DASH aim to enhance adolescent health in SSA through nutrition and PA-focused strategies. This commentary paper explores existing barriers to PA, evaluates promising on-going efforts and interventions, and highlights opportunities for promoting PA in SSA through community engagement, digital platforms, and cross-sector collaboration. Implementing sustainable and culturally tailored strategies is crucial to reversing current trends and fostering long-term health benefits for adolescents in SSA.

• Korovljev, Darinka; Ostojic, Jelena; Panic, Jovana; Ranisavljev, Marijana; Todorovic, Nikola & Nedeljkovic, David [Show all 10 contributors for this article] (2025). The Effects of 8-Week Creatine Hydrochloride and Creatine Ethyl Ester Supplementation on Cognition, Clinical Outcomes, and Brain Creatine Levels in Perimenopausal and Menopausal Women (CONCRET-MENOPA): A Randomized Controlled Trial. Journal of the American Nutrition Association (JANA). ISSN 2769-7061. 45(3), p. 199–210. doi: 10.1080/27697061.2025.2551184. Full text in Research Archive Show summary

  Objective To investigate the effects of an 8-week supplementation with varying doses of creatine hydrochloride, administered alone or in combination with creatine ethyl ester, on cognitive function, clinical outcomes, brain creatine concentrations, and biochemical markers in perimenopausal and postmenopausal women. This study specifically aimed to evaluate the potential of low-dose creatine formulations with enhanced solubility as a targeted intervention for menopause-related neurocognitive and metabolic changes. Methods A total of 36 apparently healthy perimenopausal and menopausal women (mean age 50.1 ± 5.7 years) were randomly allocated to one of four groups: low-dose creatine hydrochloride (750 mg/day), medium-dose creatine hydrochloride (1,500 mg/day), creatine hydrochloride plus creatine ethyl ester (800 mg/day), or placebo, in this randomized controlled double-blind trial. Menopausal women were defined as having no menstrual cycle for 12 consecutive months without other causes, while perimenopausal women were still menstruating but reported at least one symptom such as hot flashes, sleep disturbances, mood swings, or concentration difficulties. Results Supplementation with medium-dose creatine hydrochloride was found to be superior to placebo in enhancing reaction time (1.2 vs. 6.6%; p < 0.01), increasing frontal brain creatine levels (0.9 vs. 16.4%; p < 0.01), and favorably modulating serum lipid profiles (p < 0.05). Moreover, medium-dose creatine hydrochloride demonstrated a potential advantage over other treatments in reducing the severity of mood swings (p = 0.06). All interventions were well tolerated, with no severe adverse effects reported. Conclusion Our findings suggest that this supplementation protocol may be a promising, safe, effective, and practical dietary strategy for improving clinical outcomes and elevating brain creatine concentrations in perimenopausal and menopausal women.

• Ostojic, Sergej & Kavecan, Ivana (2025). Linking Dietary Creatine to DNA Methylation-Based Predictors of Mortality in Individuals Aged 50 and above. Lifestyle Genomics. ISSN 2504-3161. 18(1), p. 131–136. doi: 10.1159/000547260. Full text in Research Archive Show summary

  Creatine is a conditionally essential nutrient integral to cellular energy homeostasis, with emerging evidence suggesting its potential role in modulating biological aging. However, associations between dietary creatine intake and epigenetic biomarkers of mortality remain unexplored. This study investigates the relationship between dietary creatine intake and DNA methylation-derived mortality indices in US adults aged 50 years and older. Methods: Data from the NHANES 1999–2002 cycles were analyzed, including dietary creatine intake estimated from 24-h recall interviews and DNA methylation profiles measured using the Illumina EPIC array. Epigenetic mortality predictors GrimAgeMort and GrimAge2Mort were examined in relation to creatine intake. Results: Among 4,983 participants (mean age 67.6 ± 10.7 years), a significant inverse correlation was observed between dietary creatine and both GrimAgeMort (r = −0.041, p = 0.045) and GrimAge2Mort (r = −0.047, p = 0.019), indicating that higher creatine consumption was associated with lower epigenetic mortality risk scores. These associations persisted as statistically significant after adjustment for demographic variables and pertinent dietary factors. Conclusions: Higher dietary creatine intake is linked to reduced biological age acceleration and mortality risk as estimated by epigenetic biomarkers. These findings highlight creatine’s potential as a modifiable dietary factor promoting healthy aging and longevity. Further research is warranted to elucidate underlying mechanisms.

• Ranisavljev, Marijana; Kurniawan, Adi Lukas; Ferrero, Elisabetta; Shinde, Sachin; Zhao, Shuangyu & Partap, Uttara [Show all 47 contributors for this article] (2025). Community-based interventions addressing multiple forms of malnutrition among adolescents in low- and middle-income countries: a scoping review. Nutrition Journal. 24(1). doi: 10.1186/s12937-025-01136-2. Full text in Research Archive Show summary

  Background Community-based interventions hold promise for addressing adolescent malnutrition, but there is limited knowledge of their nature and impact on adolescent nutrition outcomes in low- and middle-income countries (LMICs). This scoping review aimed to characterize community-based adolescent nutrition interventions in LMICs and summarize their effects on adolescent nutrition outcomes. Methods We systematically searched MEDLINE via PubMed, Embase, and CENTRAL through the Cochrane Library for studies published between 2000 and 2023. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. Eligible studies included randomized controlled trials and quasi-experimental studies addressing adolescent malnutrition in LMIC community settings, involving adolescents aged 10–19 years. A narrative synthesis was employed to analyze and describe the evidence.

• Candow, Darren G.; Ostojic, Sergej; Chilibeck, Philip D.; Longobardi, Igor; Gualano, Bruno & Tarnopolsky, Mark A. [Show all 12 contributors for this article] (2025). Creatine monohydrate supplementation for older adults and clinical populations. Journal of the International Society of Sports Nutrition (JISSN). 22(sup1). doi: 10.1080/15502783.2025.2534130. Full text in Research Archive Show summary

  Background The biological process of aging is typically associated with a decrease in muscle quantity, muscle performance (primarily strength), bone mass and architecture, functionality and neurological/cognitive function. From a healthy aging perspective, interventions that have the potential to overcome or attenuate these decrements are clinically relevant. Methods We conducted a narrative review on the efficacy of creatine monohydrate supplementation (CrM) in older adults. Results Accumulating research shows that CrM, primarily when combined with exercise training, is safe and has beneficial effects on measures of whole-body lean body mass, regional muscle size, muscle strength, bone area and thickness, functional ability, glucose kinetics, cognition and memory. Conclusion CrM has multiple benefits in older adults and may have application for treating age-related sarcopenia, osteoporosis, frailty, and those with metabolic and neuromuscular disorders.

• Ostojic, Sergej; Prémusz, Viktória & Ács, Pongrác (2025). Creatine and cellular senescence: from molecular pathways to populational health. Experimental Gerontology. ISSN 0531-5565. 207. doi: 10.1016/j.exger.2025.112798. Full text in Research Archive Show summary

  Emerging evidence suggests that creatine, a naturally occurring amino acid derivative and conditionally essential nutrient, may modulate cellular senescence through mechanisms such as enhancing cellular energy homeostasis, mitigating oxidative stress, and influencing key signaling pathways implicated in aging processes. This review critically evaluates the current body of research, highlights existing gaps in the mechanistic understanding, and emphasizes the importance of targeted studies to further delineate creatine's role in cellular senescence and age-associated dysfunctions. By integrating perspectives from molecular biology, gerontology, and applied physiology, this paper aims to advance the understanding of creatine-based strategies as potential interventions for promoting healthy aging and preventing senescence-associated conditions.

• Ostojic, Sergej & Rátgéber, László (2025). Creatine as a mitochondrial theranostic in predictive, preventive, and personalized medicine. EPMA Journal. ISSN 1878-5077. 16(3), p. 541–553. doi: 10.1007/s13167-025-00420-9. Full text in Research Archive Show summary

  Creatine, traditionally recognized for its role in skeletal muscle energy metabolism, is increasingly emerging as a mitochondria-targeted theranostic agent with significant relevance to the framework of predictive, preventive, and personalized medicine (PPPM). However, several critical gaps currently limit its translation into clinical practice: (1) the lack of sensitive and standardized biomarkers for early detection of bioenergetic deficits, (2) limited incorporation of creatine profiling into predictive risk models, (3) insufficient personalization of supplementation strategies despite known interindividual variability in transporter function, endogenous synthesis, and tissue kinetics, and (4) underdeveloped clinical validation of advanced creatine formulations and delivery systems. This mini review addresses these unmet needs by consolidating evidence on creatine’s multifaceted biological functions—including stabilization of mitochondrial membranes, regulation of oxidative stress, support of mitochondrial biogenesis, and modulation of apoptotic signaling—across physiological and pathological states. By sustaining ATP homeostasis via the creatine kinase–phosphocreatine system and influencing mitochondrial dynamics and redox balance, creatine represents both a therapeutic and diagnostic candidate for diseases characterized by impaired bioenergetics. From a PPPM perspective, creatine profiling through biofluids, tissue sampling, and advanced imaging (e.g., proton magnetic resonance spectroscopy) offers a minimally invasive approach for early detection, patient stratification, and monitoring of mitochondrial function. Personalized intervention strategies—guided by molecular and phenotypic profiling—have the potential to maximize efficacy and minimize risk, while creatine loading or depletion tests may serve as functional biomarkers of mitochondrial reserve capacity and supplementation responsiveness. Finally, integration of creatine-centered diagnostics and therapeutics with multi-omics data, computational modeling, and digital health monitoring could overcome existing translational barriers. By reframing creatine from a sports nutrition supplement to a scalable, safe, and cost-effective component of mitochondrial medicine, this review outlines a pathway to address current diagnostic, predictive, and therapeutic deficits, ultimately supporting proactive, systems-level approaches to health maintenance and disease prevention.

• Ostojic, Sergej & Cvejic, Jelena (2025). Association between Dietary Guanidinoacetic Acid Intake and Biologically Active Folate Vitamers. Current Nutrition & Food Science. ISSN 1573-4013. 21(10), p. 1072–1074. doi: 10.2174/0115734013384113250519101449. Full text in Research Archive
• Ranisavljev, Marijana; Nedeljkovic, David; Todorovic, Nikola & Ostojic, Sergej (2025). Dietary Creatine Intake and Serum Leptin Levels: A Population-Based Analysis. Current Nutrition & Food Science. ISSN 1573-4013. doi: 10.2174/0115734013395816250715145327. Full text in Research Archive
• Todorovic, Nikola; Baltic, Sonja; Nedeljkovic, David; Kuzmanovic, Jovan; Korovljev, Darinka & Javorac, Dejan [Show all 10 contributors for this article] (2025). The Effects of 8-Week Hydrogen-Rich Water Consumption on Appetite, Body Composition, Sleep Quality, and Circulating Glucagon-like Peptide-1 in Obese Men and Women (HYDRAPPET): A Randomized Controlled Trial. Medicina. ISSN 1010-660X. 61(7). doi: 10.3390/medicina61071299. Full text in Research Archive Show summary

  Background and Objectives: Preliminary studies indicate that dihydrogen (H2) may affect molecular pathways involved in appetite regulation; however, its role in influencing patient-reported appetite outcomes in individuals with obesity remains uncertain. This randomized, placebo-controlled, double-blind trial aimed to evaluate the effects of H2 supplementation on appetite, body composition, sleep quality, obesity-specific quality of life, and related biomarkers in obese men and women. Materials and Methods: The study included 36 participants (24 females; age 42.1 ± 13.2 years; BMI 30.8 ± 4.2 kg/m2) randomized to receive either 1.0 L of hydrogen-rich water (15 mg of H2) or 1.0 L of control water (0 mg of H2) daily for eight weeks. Results: The results demonstrated that hydrogen-rich water significantly mitigated cravings (p = 0.05), improved subjective sleep quality (p = 0.05), reduced total cholesterol (p = 0.02) and LDL cholesterol (p = 0.04), and increased plasma glucagon-like peptide-1 levels (p = 0.05) compared to the control. No severe adverse effects were reported throughout the trial. Conclusions: These findings suggest that hydrogen-rich water may serve as a safe and effective dietary strategy to address appetite regulation and related metabolic indices in individuals with obesity. The study is registered at ClinicalTrials.gov (NCT06722326).

• Andjelic, Bogdan; Todorovic, Nikola; Vranes, Milan & Ostojic, Sergej (2025). Creatine-Guanidinoacetic Acid Supplementation Improves Esports Performance in Young Men. Current Nutrition & Food Science. ISSN 1573-4013. 21(10), p. 1075–1080. doi: 10.2174/0115734013384498250508080231. Full text in Research Archive
• Todorovic, Nikola; Kuzmanovic, Jovan; Javorac, Dejan & Ostojic, Sergej (2025). The impact of graded exercise to exhaustion on breath hydrogen: a pilot study. Sport Sciences for Health. ISSN 1824-7490. 21, p. 3579–3583. doi: 10.1007/s11332-025-01485-9. Full text in Research Archive Show summary

  Purpose Exercise induces transient physiological disruptions, including immune suppression and gastrointestinal (GI) disturbance. Molecular hydrogen (H₂), an endogenously produced gas with antioxidant and anti-inflammatory properties, may play a protective role in this context. While the therapeutic potential of exogenous H₂ has been widely explored, little is known about endogenous hydrogen responses to exercise. This study aimed to investigate post-exercise breath hydrogen kinetics as a potential indicator of metabolic and GI stress. Methods Thirty healthy young male athletes (age: 23.5 ± 3.8 years) completed an incremental running test to exhaustion. Breath hydrogen concentration was measured at baseline and at 5, 15, 30, 45, and 60 minutes post-exercise using an electrochemical fuel cell analyzer. The Friedman test with Bonferroni-corrected Wilcoxon post hoc comparisons was used to evaluate time-dependent changes. Results Breath hydrogen levels declined significantly at 5 minutes post-exercise (16.20 ± 16.22 ppm vs. baseline 36.37 ± 32.12 ppm; p 0.001), partially rebounded at 15 minutes (28.47 ± 33.76 ppm; p = 0.003), and approached baseline at 30 and 45 minutes. A secondary reduction was observed at 60 minutes (29.23 ± 36.55 ppm; p = 0.01). Significant deviations from baseline remained evident at multiple time points after correction. Conclusion This pilot study reveals a distinct post-exercise decline and delayed recovery in breath hydrogen concentrations, potentially reflecting impaired intestinal fermentation, increased oxidative stress, and altered redox homeostasis. Breath hydrogen may represent a novel, non-invasive biomarker of exerciseinduced physiological stress and recovery dynamics.

• Ostojic, Sergej; Baltic, Sonja & Zanini, Dragana (2025). Dietary creatine intake and mental health among the Korean population. Nutritional neuroscience. ISSN 1028-415X. 29(2), p. 239–247. doi: 10.1080/1028415X.2025.2558118. Full text in Research Archive Show summary

  Several population-based studies suggest that dietary creatine may benefit depression and cognitive function, but no research has examined overall mental health in a non-U.S. population or included adolescents. This cross-sectional study investigated the relationship between daily creatine consumption and mental health indicators using data from the 2022 Korean National Health and Nutrition Examination Survey (KNHANES). Data were analyzed from 5,257 individuals (56% female, mean age 51.1 ± 19.0 years) who provided dietary intake information and completed at least one mental health assessment. The mean daily creatine intake was 10.3 ± 9.5 mg/kg body mass (95% CI, 10.0 −10.5). One-way ANOVA showed significant differences in depression scores across quartiles of creatine intake (F = 4.003, p = 0.007), with higher depression scores in the lowest quartile compared to all others (p ≤ 0.05). The prevalence of depression was greatest among participants in the lowest quartile (6.9%) versus Q2 (3.3%), Q3 (4.3%), and Q4 (3.6%) (p≤0.05). Participants in the lowest quartile also reported higher rates of suicidal thoughts, plans, and attempts compared to those in higher quartiles (p ≤ 0.05). Higher creatine intake was associated with lower odds of generalized anxiety disorder after controlling for biomarkers of creatine turnover and demographic variables (p ≤ 0.05), but this relationship was not significant when lifestyle factors were included (p > 0.05). These findings suggest that higher dietary creatine intake may have modest protective effects against depression, suicidality, and anxiety. However, given the cross-sectional design, causality cannot be inferred, and further longitudinal and interventional studies are needed to confirm these associations and explore underlying mechanisms.

• Ostojic, Sergej (2025). Dietary creatine intake and all-cause mortality among U.S. adults: a linked mortality analysis from the NHANES study. Applied Physiology, Nutrition and Metabolism. ISSN 1715-5312. 50, p. 1–6. doi: 10.1139/apnm-2025-0001. Full text in Research Archive Show summary

  Evidence linking dietary creatine intake with mortality remains scarce and inconclusive. This study aimed to investigate the relationship between creatine consumption and all-cause mortality, as well as to evaluate the potential impact of meeting the recommended dietary creatine intake of ≥1 g per day in a nationally representative sample of U.S. adults. We evaluated creatine intake, estimated from a single 24 h dietary recall in the 1999–2000 National Health and Nutrition Examination Survey, with mortality follow-up extending through 2019. Of the 4041 participants enrolled at baseline, 858 deaths were recorded over a median follow-up period of 19.8 years. Creatine as a continuous variable (grams per day) had inverse association with all-cause mortality (B = −0.094; P = 0.04). The hazard ratio for all-cause mortality was 0.85 (95% CI: 0.72–1.00) for participants consuming at least 1 g of creatine per day, compared to those consuming less than 1 g/day (P = 0.05), suggesting that individuals meeting the recommended creatine intake had a significantly lower risk of early mortality compared to those with suboptimal intake. Proportional hazards regression analysis indicated that this association remained robust after adjusting for certain covariates, such as dietary macronutrients (B = −0.234; P = 0.01) and physical examination measures (B = −0.206; P = 0.02); however, it weakened when demographic and lifestyle factors were included in the model. In this sample of U.S. adults, higher creatine intake was inversely associated with all-cause mortality; however, this relationship may be influenced by other contributing factors. These findings underscore the need for further research on the relationship between dietary creatine intake and mortality outcomes.

• Ostojic, Sergej (2025). High Prevalence of Low Creatine Intake among Individuals Following Common Special Diets. Annals of Nutrition and Metabolism. ISSN 0250-6807. p. 1–4. doi: 10.1159/000549528. Full text in Research Archive Show summary

  Introduction: Creatine is a conditionally essential nutrient central to cellular energy metabolism, with roughly half of daily requirements derived from dietary sources found exclusively in animal-based foods. Insufficient dietary creatine intake has been linked to various adverse health outcomes, yet data on creatine adequacy among individuals following special diets remain limited. This study examined the prevalence of low dietary creatine intake among US individuals adhering to different special diets using cumulative data from the National Health and Nutrition Examination Survey (NHANES). Methods: Data from NHANES 2003–2023 cycles were merged to identify participants (≥1 year old) reporting adherence to a special diet in the Dietary Data domain. Self-reported diets were categorized into thirteen groups (e.g., weight-loss, diabetic, low-fat, low-carbohydrate, gluten-free). Dietary creatine intake, estimated using established methods and excluding supplements, was classified as adequate (≥1 g/day) or inadequate (<1 g/day). Differences in the prevalence of inadequate creatine intake across diet types were assessed using chi-square tests with Bonferroni-adjusted post hoc comparisons. Results: Among 8,407 participants (57.8% female; mean age = 45.0 ± 21.5 years) reporting adherence to a single special diet, mean creatine intake was 0.82 ± 0.82 g/day, with 69.5% classified as having inadequate intake. The prevalence of low creatine intake differed significantly across diet types (p < 0.0001), ranging from 83.3% in low-fiber diets to 60.4% in renal diets. Individuals following low-carbohydrate diets exhibited a significantly lower prevalence of inadequate intake (p = 0.00097), while high- and low-fiber, gluten-free, and weight-loss diets were associated with higher prevalence rates. Women showed greater creatine insufficiency than men across several dietary categories. Conclusion: Inadequate dietary creatine intake is highly prevalent among individuals following a variety of special diets in the US population. Restrictive or plant-forward regimens appear particularly associated with insufficient intake, underscoring the need for nutritional strategies – such as creatine-fortified foods or supplementation – to maintain optimal creatine homeostasis and support metabolic health in at-risk groups.

• Ostojic, Sergej (2025). The evolving role of creatine in public health: from food-based nutrient to supplement and beyond. Public Health Nutrition (PHN). ISSN 1368-9800. 28(1). doi: 10.1017/S1368980025101390. Full text in Research Archive Show summary

  Creatine is a vital bioenergetic compound that remains largely overlooked within food systems despite its well-established role in human health and performance. Unlike creatinine – a downstream breakdown product of creatine metabolism commonly measured as a biomarker of kidney function – creatine functions as an energy buffer, facilitating the rapid regeneration of ATP in tissues with high metabolic demands such as skeletal muscle, brain and heart. Although a portion of daily creatine requirements is met through endogenous synthesis, dietary intake – primarily from animal-source foods – remains essential to maintain optimal physiological levels. Emerging evidence indicates that suboptimal creatine status, or creatine insufficiency, may be widespread, particularly among vegetarians, vegans, older adults, individuals with chronic illness and those with increased energy needs. This paper examines the evolving role of creatine across four domains: its natural occurrence in foods, incorporation into fortified food products, use as a dietary supplement and potential future classification as a pharmaceutical agent. Special emphasis is placed on differences in regulatory status, intended use, dosage, labelling and public health implications. In light of mounting evidence that creatine insufficiency may contribute to adverse outcomes – including impaired cognition, reduced muscular performance and vulnerability to stressors – integrating creatine into food policy and nutrition strategies represents a promising, scalable and preventive approach to improve population health.

• Ostojic, Sergej & Grasaas, Erik (2025). Dietary Creatine and Hydration Biomarkers in the General Population: NHANES 1999–2023. Food Science & Nutrition. 13(7). doi: 10.1002/fsn3.70524. Full text in Research Archive Show summary

  Creatine is widely recognized for its performance-enhancing and neuroprotective properties; however, its impact on hydration status at the population level remains poorly understood. This study investigated the relationship between dietary creatine intake and hydration biomarkers in a nationally representative sample derived from the National Health and Nutrition Examination Survey (NHANES). Data from the biannual 1999 and 2023 NHANES cycles were harmonized and analyzed, including dietary recall data and hydration biomarkers such as plasma osmolality, urine specific gravity (USG), total body water (TBW), intracellular fluid (ICF), and extracellular fluid (ECF) volumes. Valid data on dietary creatine intake were obtained from 98,681 participants, with serum osmolality measured in 69,144 individuals, fluid volumes assessed in 12,369, and USG evaluated in 6274 respondents. Total daily dietary creatine intake was expressed in milligrams per kilogram of body mass and categorized into quantiles. Associations were evaluated using multivariate regression models, adjusted for potential confounders, including gender, age, daily intake of caffeine, alcohol, sodium, water, protein, and total caloric intake. Both the lowest and highest creatine intake quantiles were significantly associated with altered plasma osmolality levels and an increased prevalence of hypoosmolality (p < 0.01), relative to moderate creatine intake (4.27–10.19 mg/kg). Higher creatine intake was also associated with reduced TBW, ICF, and ECF volumes (p < 0.01). Notably, a significantly lower risk of hypoosmolality was observed in the 50th percentile (OR = 0.861; p = 0.035) and the 75th percentile (OR = 0.832; p = 0.010) of creatine intake. Our findings challenge the prevailing notion that dietary creatine universally enhances hydration. While moderate intake from regular foods appears to have a neutral effect, higher intake levels may disrupt systemic fluid balance. Further research is warranted to explore the underlying physiological mechanisms and evaluate the long-term effects of creatine intake on hydration homeostasis.

• Ostojic, Sergej; Stajer, Valdemar; Todorovic, Nikola; Ranisavljev, Marijana; Andjelic, Bogdan & Panic, Jovana [Show all 9 contributors for this article] (2025). Effects of Short-Term Creatine Nitrate Plus Creatinine Intake on Creatine Pharmacokinetics and Safety Biomarkers in Healthy Adults. Current Nutrition & Food Science. ISSN 1573-4013. 21(3), p. 388–394. doi: 10.2174/0115734013307562240702114411. Full text in Research Archive
• Andjelic, Bogdan; Lainovic, Tijana; Todorovic, Nikola; Panic, Jovana; Vranes, Milan & Stajer, Valdemar [Show all 7 contributors for this article] (2025). Exercise affects salivary biomarkers of creatine metabolism in healthy adults. Sports Medicine and Health Science (SMHS). doi: 10.1016/j.smhs.2025.03.010. Full text in Research Archive
• Ranisavljev, Marijana; Stajer, Valdemar; Todorovic, Nikola; Ostojic, Jelena; Cvejic, Jelena Helena & Steinert, Robert E. [Show all 7 contributors for this article] (2025). The effects of 3-month supplementation with synbiotic on patient-reported outcomes, exercise tolerance, and brain and muscle metabolism in adult patients with post-COVID-19 chronic fatigue syndrome (STOP-FATIGUE): a randomized Placebo-controlled clinical trial. European Journal of Nutrition. ISSN 1436-6207. 64(1). doi: 10.1007/s00394-024-03546-0. Full text in Research Archive Show summary

  Purpose: Considering the observed gastrointestinal issues linked to post-COVID-19 myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), beneficially modulating the gut microbiota could offer a safe, cost-effective nutritional strategy. This trial aimed to evaluate the effects of medium-term synbiotic supplementation on patient-reported outcomes, exercise tolerance, and tissue metabolism in patients with post-COVID-19 ME/CFS. Methods: Between September 2022 and December 2023, we investigated the impact of 3-month supplementation with a synbiotic mixture including L. rhamnosus DSM 32550, Humiome® L. plantarum DSM 34532, B. lactis DSM 32269, B. longum DSM 32946, fructooligosaccharides and zinc, on predetermined primary and secondary outcome measures in twenty six post-COVID-19 ME/CFS patients utilizing a parallel-group, randomized, placebo-controlled, double-blind design. Results: Both the synbiotic and placebo intake resulted in a significant reduction in general fatigue after 3 months compared to the baseline values (P ≤ 0.05). This was accompanied by a significant interaction effect (time vs. treatment) for post-exercise malaise (P = 0.02), with synbiotic superior to placebo to attenuate post-exercise malaise. The synbiotic also demonstrated a significant advantage over placebo in increasing choline levels at the thalamus (P = 0.02), and creatine levels at left frontal white matter (P = 0.05) and left frontal grey matter (P = 0.04). Conclusion: Taking the synbiotic mixture for three months improves tissue metabolism and mitigates clinical features of post-COVID-19 fatigue syndrome. The presented data show promise in addressing the widespread issue of ME/CFS following the COVID-19 pandemic; however, further validation is needed before endorsing the synbiotics within this clinical context. The study is registered at ClinicalTrials.gov (NCT06013072).

• Todorović, Nikola; Kuzmanovic, Jovan; Javorac, Dejan & Ostojic, Sergej (2025). Role of molecular hydrogen in obesity treatment: modulation of GLP-1, irisin, and PGC-1α for improved metabolism. Medical Gas Research (MGR). doi: 10.4103/mgr.MEDGASRES-D-24-00146. Full text in Research Archive
• Nedeljkovic, David & Ostojic, Sergej (2025). Dietary exposure to creatine-precursor amino acids in the general population. Amino Acids. ISSN 0939-4451. 57. doi: 10.1007/s00726-025-03460-7. Full text in Research Archive Show summary

  Background Creatine is a semi-essential nutrient that plays a critical role in energy metabolism, with dietary intake and endogenous synthesis contributing to overall creatine availability. While dietary creatine intake has been studied extensively, limited data exist on the dietary exposure to its precursor amino acids—glycine, arginine, and methionine—and their contribution to endogenous creatine synthesis. This study aimed to assess the dietary intake of these precursors in U.S. children and adults using data from the Third National Health and Nutrition Examination Survey (NHANES III) and to compare endogenous creatine synthesis with direct dietary creatine intake. Methods We analyzed NHANES III dietary recall data from 29,945 individuals aged 2 years and older. Intakes of glycine, arginine, methionine, and creatine were calculated per kilogram of body weight. The contribution of precursor amino acids to endogenous creatine synthesis was estimated using established metabolic conversion factors. Results The mean daily intakes of glycine, arginine, methionine, and creatine were 59.6 ± 0.4 mg/kg, 77.2 ± 0.5 mg/kg, 31.9 ± 0.2 mg/kg, and 15.5 ± 0.1 mg/kg, respectively. Estimated endogenous creatine synthesis from precursor amino acids was significantly greater than dietary creatine intake across all age groups (P < 0.01), with precursor-derived creatine production averaging 41.9 ± 0.3 mg/kg body weight per day, approximately 2.7 times higher than dietary creatine intake. Creatine precursor availability declined with age, with the lowest values observed in individuals aged ≥ 65 years. Conclusion This study provides the first comprehensive evaluation of total creatine availability in a representative U.S. population, highlighting the predominance of endogenous synthesis over direct dietary intake. These findings suggest that creatine metabolism is largely dependent on precursor amino acid intake and that certain populations, particularly older adults, may be at higher risk for reduced creatine availability. Future research should explore the physiological implications of these findings and potential dietary interventions to optimize creatine status across the lifespan.

• Todorovic, Nikola; Nedeljkovic, David; Panic, Jovana & Ostojic, Sergej (2025). Sleep deprivation elevates circulating creatine levels in healthy adults: a pilot study. Sleep and Biological Rhythms. ISSN 1446-9235. 23, p. 477–479. doi: 10.1007/s41105-025-00587-8. Full text in Research Archive Show summary

  This pilot study investigated the impact of a 24-h sleep deprivation period on circulating biomarkers of creatine metabolism in 23 healthy adults (24.6±4.3 years; 7 females). Contrary to the hypothesis that sleep deprivation would reduce creatine levels, serum creatine significantly increased post-deprivation (95% CI−3.66 to 25.22 μmol/L; P=0.03), while guanidinoacetic acid and creatinine levels remained unchanged. Our findings suggest a complex relationship between sleep deprivation and creatine metabolism, emphasizing the need for further research using advanced biomarkers to elucidate these mechanisms and assess creatine’s potential protective role under stress conditions.

• Nedeljkovic, David; Baltic, Sonja; Todorovic, Nikola & Ostojic, Sergej (2025). Creatine Intake Is Not Associated With Elevated Circulating Cystatin C Levels in Individuals With and Without Kidney Dysfunction in the General Population. Journal of the American Nutrition Association (JANA). ISSN 2769-7061. 44(4), p. 338–341. doi: 10.1080/27697061.2024.2432484. Full text in Research Archive Show summary

  Objective The potential adverse effects of dietary creatine on kidney health are rarely addressed at the population level, particularly in individuals with preexisting kidney disease. This study aimed to evaluate the association between dietary creatine intake and serum cystatin C levels in participants with and without kidney failure, utilizing data from the 1999–2001 National Health and Nutrition Examination Survey (NHANES) round. Method A total of 4969 individuals (50.0% female; mean age 51.2 ± 23.9 years) who provided information on dietary creatine intake and had serum cystatin C levels measured were included in the final analysis. Results Linear regression across the entire sample revealed a significant inverse association between daily creatine intake and cystatin C concentrations (unstandardized B = −0.003; ß = −0.067; p < 0.001), indicating that for each additional milligram of creatine intake, the expected reduction in cystatin C levels was 0.003 mg/dL. In a subsample of respondents with kidney dysfunction, a significant negative association was found between creatine intake and cystatin C levels (unstandardized B = −0.024; ß = −0.165; p = 0.046). Conclusions Findings suggest that food-derived creatine does not pose a risk of kidney stress, even for individuals with kidney failure, and might be considered a renoprotective nutrient.

• Antonio, Jose; Brown, Ann F.; Candow, Darren G.; Chilibeck, Philip D.; Ellery, Stacey J. & Forbes, Scott C. [Show all 20 contributors for this article] (2025). Part II. Common questions and misconceptions about creatine supplementation: what does the scientific evidence really show? Journal of the International Society of Sports Nutrition (JISSN). 22(1), p. 1–41. doi: 10.1080/15502783.2024.2441760. Full text in Research Archive Show summary

  Creatine monohydrate supplementation (CrM) is a safe and effective intervention for improving certain aspects of sport, exercise performance, and health across the lifespan. Despite its evidence-based pedigree, several questions and misconceptions about CrM remain. To initially address some of these concerns, our group published a narrative review in 2021 discussing the scientific evidence as to whether CrM leads to water retention and fat accumulation, is a steroid, causes hair loss, dehydration or muscle cramping, adversely affects renal and liver function, and if CrM is safe and/or effective for children, adolescents, biological females, and older adults. As a follow-up, the purpose of this paper is to evaluate additional questions and misconceptions about CrM. These include but are not limited to: 1. Can CrM provide muscle benefits without exercise? 2. Does the timing of CrM really matter? 3. Does the addition of other compounds with CrM enhance its effectiveness? 4. Does CrM and caffeine oppose each other? 5. Does CrM increase the rates of muscle protein synthesis or breakdown? 6. Is CrM an anti-inflammatory intervention? 7. Can CrM increase recovery following injury, surgery, and/or immobilization? 8. Does CrM cause cancer? 9. Will CrM increase urine production? 10. Does CrM influence blood pressure? 11. Is CrM safe to consume during pregnancy? 12. Does CrM enhance performance in adolescents? 13. Does CrM adversely affect male fertility? 14. Does the brain require a higher dose of CrM than skeletal muscle? 15. Can CrM attenuate symptoms of sleep deprivation? 16. Will CrM reduce the severity of and/or improve recovery from traumatic brain injury? Similar to our 2021 paper, an international team of creatine research experts was formed to perform a narrative review of the literature regarding CrM to formulate evidence-based responses to the aforementioned misconceptions involving CrM.

• Grasaas, Erik; Sandbakk, Øyvind Bucher; Ostojic, Sergej; Horverak, May Olaug & Stea, Tonje Holte (2025). Socioeconomic status, sport participation, and school-related outcomes among Norwegian adolescents: a cross-sectional analysis. Frontiers in Sports and Active Living. 7. doi: 10.3389/fspor.2025.1613391. Full text in Research Archive Show summary

  Background: Extensive research highlights the critical role of sport and physical activity (PA) engagement during adolescence, as it is strongly associated with enhanced subjective well-being, reduced risk of mental health problems, and prevention of chronic diseases in adulthood. Thus, it is highly important to identify key barriers of sport participation in adolescence. The present study aimed to; (1) describe socioeconomic status (SES) across different sport disciplines among current participants and sport dropouts, (2) examine possible associations between sport participation and sport dropouts on school-related outcomes. Methods: School-based cross-sectional data among 90,091 adolescents aged 16–19 years were collected across Norway between 2021 and 2023. A self-report questionnaire was used to assess information about sociodemographic background, current and previous sport participation, and school-related factors, including perceived school stress, teacher care, feeling tired at school and sense of belonging at school. Adjusted binary logistic regressions were conducted using IBM SPSS Statistics. Results: Adolescents currently participating in sport reported higher SES compared to sport dropouts (2.13 ± 0.51 vs. 1.97 ± 0.61, p < 0.01). Tennis participants demonstrated the highest SES of 2.39 ± 0.44, while motorsport participants revealed the lowest score (1.82 ± 0.49). The highest sport attrition rate (80.2%) was revealed among adolescents from the lowest SES level. Current sport participants reported favorable school-related outcomes and PA engagement compared to sport dropouts (all, p < 0.01). Adjusted logistic analyses showed that participation in sport activities was associated with lower odds of perceived school stress [OR = 0.83; 95% CI (0.81–0.86)] and being tired during school hours [OR = 0.74; 95% CI (0.71–0.77)], and higher odds for perceived teacher care [OR = 1.17; 95% CI (1.12–1.22)] and perceived sense of belonging [OR = 1.36; 95% CI (1.31–1.42)]. Conclusions: Higher SES was found among adolescents participating in sport compared to sport dropouts, underscoring the importance of promoting affordable sport opportunities during adolescence. Current sport participation was associated with favorable school-related outcomes compared to sport dropouts, such as lower odds for perceived school stress and tiredness in school, and higher odds of perceived sense of belonging in school and perceived teacher care.

• Todorovic, Nikola; Nedeljkovic, David; Javorac, Dejan; Stajer, Valdemar & Ostojic, Sergej (2025). The effects of low-dose guanidinoacetic acid supplementation on total plasma homocysteine in healthy men: A pilot study. International Journal of Nutrition, Pharmacology, Neurological Diseases. ISSN 2231-0738. doi: 10.4103/ijnpnd.ijnpnd_127_24. Full text in Research Archive
• Ostojic, Sergej; Candow, Daren G. & Tarnopolsky, Mark A. (2025). Creatine and post-viral fatigue syndrome: an update. Journal of the International Society of Sports Nutrition (JISSN). 22(1). doi: 10.1080/15502783.2025.2517278. Full text in Research Archive Show summary

  Post-viral fatigue syndrome, classified as a neurological condition by the WHO (ICD-11 code: 8E49), manifests as persistent fatigue, cognitive difficulties, and post-exertional malaise following viral infections. It shares commonalities with chronic fatigue syndrome and myalgic encephalomyelitis but is distinct due to its Association with preceding viral events. Emerging research identifies bioenergetic disruptions, particularly mitochondrial dysfunction and impaired creatine metabolism, as key contributors. Recent studies suggest creatine supplementation may alleviate symptoms and improve energy metabolism. This narrative review summarizes recent advancements in utilizing creatine as a diagnostic and therapeutic target for post-viral fatigue syndrome and explores future directions for its application in managing this perplexing condition.

• Kuzmanovic, Jovan; Todorovic, Nikola; Ranisavljev, Marijana; Javorac, Dejan; Korovljev, Darinka & Tarnava, Alex [Show all 8 contributors for this article] (2025). The effects of drinking hydrogen-rich water for six weeks on exercise-related biomarkers in exercise-naïve men and women over 50 years following resistance training program: a randomized controlled pilot trial. Research in Sports Medicine: An International Journal. ISSN 1543-8627. 33(6), p. 711–721. doi: 10.1080/15438627.2025.2521474. Full text in Research Archive Show summary

  The primary objective of this pilot study was to assess the impact of consuming hydrogen-rich water (HRW) for a duration of six weeks on exercise-related biomarkers in previously untrained men and women aged over 50 years, subsequent to a resistance training program. Twenty-seven apparently healthy middle-aged adults (age 57.6 ± 6.7 years; 18 females) voluntarily provided written consent to participate in this randomized, placebo-controlled experimental trial. All participants were allocated in a double-blind parallel-group design to receive either HRW (12 mg of dihydrogen per serving) or control water (<0.1 ppm of dihydrogen) administered two times per day during a 6-week intervention interval. Muscle performance indices showed a significant improvement following both HRW and control water interventions compared to the baseline values (p ≤ 0.05). HRW led to a significant increase in serum free testosterone and cortisol levels, along with reductions in total cholesterol and LDL-cholesterol levels at the follow-up (p ≤ 0.05). Moreover, HRW significantly outperformed the control water in reducing biomarkers of acute muscular damage caused by resistance exercise (p ≤ 0.05) and tended to outcompete placebo in improving sleep quality (p = 0.119). HRW could be advanced as a risk-free and effective beverage for promoting training-specific adaptations in exercise-naïve men and women over 50 years of age.

• Todorović, Nikola & Ostojic, Sergej (2024). Hydrogen as an innovative nootropic in health and disease. Nutrition and Health. ISSN 0260-1060. doi: 10.1177/02601060241266389. Full text in Research Archive
• Escribano-Ott, Ignacio; Mielgo-Ayuso, Juan; Ochóa-Lacar, Javier; Calleja-González, Julio & Ostojic, Sergej (2024). Beyond creatine: evaluating guanidino acetic acid as a novel ergonutritional aid for basketball players. Archivos de Medicina del Deporte. ISSN 0212-8799. 41(2), p. 70–77. doi: 10.18176/archmeddeporte.00159. Full text in Research Archive
• Kurniawan, Adi Lukas; Ranisavljev, Marijana; Partap, Uttara; Shinde, Sachin; Ferrero, Elisabetta & Ostojic, Sergej [Show all 12 contributors for this article] (2024). Community-based interventions targeting multiple forms of malnutrition among adolescents in low-income and middle-income countries: protocol for a scoping review. BMJ Open. 14(3), p. e078969–e078969. doi: 10.1136/bmjopen-2023-078969. Full text in Research Archive
• Fernández-Landa, Julen; Todorovic, Nikola; Santibañez-Gutierrez, Asier; Ostojic, Sergej; Calleja-González, Julio & Sekulic, Djordje [Show all 7 contributors for this article] (2024). Effects of HMB on Endurance Performance in a Healthy Population: A Systematic Review and Meta-Analysis. Journal of Strength and Conditioning Research. ISSN 1064-8011. 38(4), p. E202–E210. doi: 10.1519/JSC.0000000000004690. Full text in Research Archive
• Kurniawan, Adi; Ostojic, Sergej; Shinde, Sachin; Laxy, Michael; Neumann, Christine & Berhane, H. [Show all 14 contributors for this article] (2024). Enhancing adolescent and youth health through nutrition fluency in Sub-Saharan Africa: ARISE-NUTRINT initiative. Perspectives in Public Health. ISSN 1757-9139. 144(4), p. 215–218. doi: 10.1177/17579139241251636. Full text in Research Archive Show summary

  Adolescents and young people, aged 10–24, experience critical developmental periods for physical, cognitive, behavioral, and social growth, which influence their lifelong health trajectory.1 The Sub-Saharan African (SSA) population’s one-third comprises people aged 10–24 years, necessitating a public health approach to promote healthy nutrition. Adolescents and youth, who are particularly susceptible to undernutrition and diet-related obesity compared to other age groups, face increased risks for non-communicable diseases (NCDs), a major public health challenge that accounts for 70% of global deaths annually.2,3 In addition, between 1980 and 2015, the prevalence of overweight/obesity in adolescents increased in SSA, affecting 7.6% of boys and 15.4% of girls.4 One driver of this increase in obesity is the increase in the consumption of sugar-sweetened beverages (SSBs) – a trend that was most pronounced in countries in SSA.5 Despite the availability of cost-effective and evidence-based practices to address NCDs in low- and middle-income countries (LMICs),6 implementing these interventions remains a significant challenge, particularly in promoting healthy behaviors among adolescents and youth.7 In SSA, limited studies have focused on identifying the barriers and facilitators to implementing interventions and policies that promote healthy behaviors among adolescents and youth.2,7 Many of these efforts are concentrated on school-going adolescents and exclude those who are not in educational institutions and more vulnerable to unhealthy lifestyles. To be effective, new policies and programs need to consider the diverse profile of adolescents and youth, and involve multifaceted and multilevel efforts across education, health, food, social protection, and digital technology. In addition, various factors affect adolescent and youth diets and nutrition, physical activity, and healthy lifestyle behaviors. However, most intervention studies have focused on micronutrient supplementation. Finally, research is scarce on the long-term costs, effects, and impact of evidence-based interventions in this region.

• Ostojic, Sergej; Stea, Tonje Holte; Ellery, Stacey & Smith-Ryan, Abbey (2024). Association between dietary intake of creatine and female reproductive health: Evidence from NHANES 2017–2020. Food Science & Nutrition. 12(7), p. 4893–4898. doi: 10.1002/fsn3.4135. Full text in Research Archive
• Slankamenac, Jelena; Ranisavljev, Marijana; Todorovic, Nikola; Stajer, Valdemar; Candow, Darren G & Ratgeber, Laszlo [Show all 9 contributors for this article] (2024). Eight-week creatine-glucose supplementation alleviates clinical features of long COVID. Journal of Nutritional Science and Vitaminology. ISSN 0301-4800. 70(2), p. 174–178. doi: 10.3177/jnsv.70.174. Full text in Research Archive
• Grasaas, Erik; Ostojic, Sergej & Sandbakk, Øyvind Bucher (2024). Associations between levels of physical activity and satisfaction with life among Norwegian adolescents: a cross-sectional study. Frontiers in Sports and Active Living. 6. doi: 10.3389/fspor.2024.1437747. Full text in Research Archive Show summary

  Background: A robust association between physical activity (PA) and satisfaction with life (SWL) has been established, wherein self-efficacy has been identified as a mediator across different populations. However, there is a need to further examine the relationship between PA and SWL and whether self-efficacy act a as mediator within different levels of PA among Norwegian adolescents. Thus, the objective of this study was to explore the relationship between levels of PA and SWL by testing for self-efficacy as a possible mediator.<p><p> Methods: Cross-sectional data from the 2022 Norwegian Ungdata Survey was utilized. Data included demographics and various health data that was collected anonymously. The electronic survey took place in classrooms and was administered by the respective teacher. Permission to access and use data was approved by the Norwegian Agency for Shared Services in Education and Research (SIKT). Statistical analyses were conducted using the PROCESS macro by Andrew Hayes for SPSS software. <p>Results: Descriptive findings revealed that girls reported lower self-efficacy than boys (14.2 vs. 15.5, with a maximum of 20) and lower SWL (6.8 vs. 7.6, with a maximum of 10). About one out of five girls and one out of seven boys reported no days of weekly PA, whereas 4% of girls and 9.5% of boys adhered to the PA-recommendation of 60-min of daily exercise. Associations between PA levels and SWL was mediated by self-efficacy (all p < 0.05), with the highest indirect effect (56.3%) revealed in the association between those adhering to the PA-recommendations and SWL. <p>Conclusions: Norwegian girls reported more sedentary behavior, less PA, lower self-efficacy, and lower SWL than boys across all grade levels. Mediation analysis revealed that up to 56.3% of the enhancement in SWL among those adhering to 60-min of PA recommendations was explained by increased self-efficacy. Norwegian government and policymakers should promote initiatives and regulations focusing on higher levels of PA to foster a resilient adolescent population with higher individual beliefs and higher subjective wellbeing.

• Zhou, Bin; Cesare, Mariachiara Di; Aguilar-Salinas, Carlos A; Ahmad, Nor Ani; Bovet, Pascal & Chen, Zhengming [Show all 51 contributors for this article] (2024). General and abdominal adiposity and hypertension in eight world regions: a pooled analysis of 837 population-based studies with 7·5 million participants. The Lancet. ISSN 0140-6736. 404(10455), p. 851–863. doi: 10.1016/S0140-6736(24)01405-3. Full text in Research Archive Show summary

  Background: Adiposity can be measured using BMI (which is based on weight and height) as well as indices of abdominal adiposity. We examined the association between BMI and waist-to-height ratio (WHtR) within and across populations of different world regions and quantified how well these two metrics discriminate between people with and without hypertension. Methods: We used data from studies carried out from 1990 to 2023 on BMI, WHtR and hypertension in people aged 20–64 years in representative samples of the general population in eight world regions. We graphically compared the regional distributions of BMI and WHtR, and calculated Pearson's correlation coefficients between BMI and WHtR within each region. We used mixed-effects linear regression to estimate the extent to which WHtR varies across regions at the same BMI. We graphically examined the prevalence of hypertension and the distribution of people who have hypertension both in relation to BMI and WHtR, and we assessed how closely BMI and WHtR discriminate between participants with and without hypertension using C-statistic and net reclassification improvement (NRI). Findings: The correlation between BMI and WHtR ranged from 0·76 to 0·89 within different regions. After adjusting for age and BMI, mean WHtR was highest in south Asia for both sexes, followed by Latin America and the Caribbean and the region of central Asia, Middle East and north Africa. Mean WHtR was lowest in central and eastern Europe for both sexes, in the high-income western region for women, and in Oceania for men. Conversely, to achieve an equivalent WHtR, the BMI of the population of south Asia would need to be, on average, 2·79 kg/m2 (95% CI 2·31–3·28) lower for women and 1·28 kg/m2 (1·02–1·54) lower for men than in the high-income western region. In every region, hypertension prevalence increased with both BMI and WHtR. Models with either of these two adiposity metrics had virtually identical C-statistics and NRIs for every region and sex, with C-statistics ranging from 0·72 to 0·81 and NRIs ranging from 0·34 to 0·57 in different region and sex combinations. When both BMI and WHtR were used, performance improved only slightly compared with using either adiposity measure alone. Interpretation: BMI can distinguish young and middle-aged adults with higher versus lower amounts of abdominal adiposity with moderate-to-high accuracy, and both BMI and WHtR distinguish people with or without hypertension. However, at the same BMI level, people in south Asia, Latin America and the Caribbean, and the region of central Asia, Middle East and north Africa, have higher WHtR than in the other regions. Funding: UK Medical Research Council and UK Research and Innovation (Innovate UK).

• Ostojic, Sergej & Cvejic, Jelena (2024). Food-sourced guanidinoacetic acid and methylation cycle biomarkers in individuals aged one year and older: a population-based cross-sectional study. European Journal of Nutrition. ISSN 1436-6207. doi: 10.1007/s00394-024-03493-w. Full text in Research Archive
• Farkas, Gábor; Bábszky, Zsófia; Stajer, Valdemar & Ostojic, Sergej (2024). Dose-escalation study with supplemental creatine-guanidinoacetate in healthy adults. Progress in Nutrition. ISSN 1129-8723. 26(3-4). doi: 10.23751/pn.v26i3-4.16416. Full text in Research Archive
• Ostojic, Sergej; Stajer, Valdemar; Todorovic, Nikola; Ranisavljev, Marijana; Andjelic, Bogdan & Panic, Jovana [Show all 7 contributors for this article] (2024). Effects of short-term creatine nitrate plus creatinine on creatine pharmacokinetics and safety biomarkers in healthy adults. Current Nutrition & Food Science. ISSN 1573-4013. doi: 10.2174/01/0115734013307562240702114411. Full text in Research Archive
• Ranisavljev, Marijana; Todorovic, Nikola; Stajer, Valdemar & Ostojic, Sergej (2024). Post-marketing surveilance study of creatine-guanidinoacetic acid safety in healthy adults. Frontiers in Nutrition. 11, p. 1414308–1414308. doi: 10.3389/fnut.2024.1414308. Full text in Research Archive Show summary

  A post-marketing surveillance study assessed the adverse events and possible risk of elevated homocysteine levels after the supplementation with creatine-guanidinoacetic acid mixture in apparently healthy adults. The participants were recruited through social media platforms and online discussion boards, with side effects and total plasma homocysteine (T-Hcy) levels evaluated regularly during a supplementation period of 6 months. Thirthy eight individuals (n = 38, 34.2% female) completed the evaluation period and were included in the final analyses. Serious side effects were absent. Two participants (5.3%) reported transitional nausea during the introductory weeks of the supplementation; no participants stopped the treatment. Baseline T-Hcy levels were 11.6 ± 3.1 μmol/L (95% confidence interval [CI], from 10.6 to 12.6). The intervention induced a mild reduction in T-Hcy levels across the monitoring period (p = 0.028), with T-Hcy levels after 1, 2, 3, and 6 months were 10.4 ± 3.0 μmol/L, 10.6 ± 2.9 μmol/L, 10.1 ± 2.7 μmol/L, and 9.3 ± 2.8 μmol/L, respectively. These findings suggest the overall tolerability of creatine-guanidinoacetic mixture in healthy adults, with homocysteine-increasing risk of no concern.

• Grasaas, Erik; Ostojic, Sergej; Sandbakk, Øyvind Bucher; Bjørnsen, Gunn; Sylta, Øystein & Major, Daniel Høgli [Show all 7 contributors for this article] (2024). The relationship between perceived school stress and satisfaction with life among Norwegian school-based adolescents and the moderating role of perceived teacher care: a cross-sectional study. BMC Public Health. 24(1). doi: 10.1186/s12889-024-20246-w. Full text in Research Archive Show summary

  Background - Perceived stress from schoolwork and perceived teacher care are shown to influence adolescents’ life satisfaction. However, there is a need to further explore how levels of perceived school stress affect life satisfaction of Norwegian adolescents across gender and school levels using nationwide data, and whether this association is moderated by perceived teacher care. Hence, this paper sought to: (1) describe perceived school stress, perceived teacher care and satisfaction with life in Norwegian adolescents stratified by gender and school level, (2) examine the association between perceived school stress and satisfaction with life by testing perceived teacher care as a possible moderator and (3) explore the association between perceived teacher care and adolescents’ satisfaction with life.<p> <p>Methods - We utilized cross-sectional data from the Norwegian Ungdata Survey from 2021, encompassing adolescents from lower and upper secondary school. Two-thirds of all Norwegian adolescents participated in the Ungdata Survey from 2021. All data is anonymous. The study variables are presented according to lower and upper secondary school as well as gender. Linear regressions were conducted and adjusted for socioeconomic status (SES) by using SPSS.<p> <p>Results - In total, 139,841 adolescents were included. Girls exhibited higher perceived school stress, lower perceived teacher care, and lower life satisfaction than boys in both lower and secondary school (all p < 0.01). Strong inverse associations on satisfaction with life were found in both genders in lower and upper secondary school among those who reported very frequent perceived school stress, with perceived teacher care moderating the relationship (B= -0.67; 95% CI [-0.70 to -0.65], P < 0.01]). Moreover, robust associations were unveiled between high and low levels of perceived teacher care and life satisfaction across gender and school level.<p> <p>Conclusions - Higher perceived school stress was strongly inversely associated with life satisfaction in Norwegian adolescents, in both girls and boys, and in both lower and secondary school. Teacher care was identified as a moderator and seems to play a crucial part in the everyday life of Norwegian adolescents. These implications extend to teacher education, practice, and policy, which should be aware of the pivotal role of perceived teacher care on Norwegian school-based adolescents‘ life satisfaction.

• Grasaas, Erik; Ostojic, Sergej & Jahre, Henriette (2024). Adherence to sleep recommendations is associated with higher satisfaction with life among Norwegian adolescents. BMC Public Health. 24(1). doi: 10.1186/s12889-024-18725-1. Full text in Research Archive Show summary

  Background: Sleep plays a crucial role in the health and well-being of adolescents; however, inadequate sleep is frequently reported in numerous countries. This current paper aimed to describe sleep duration, factors impacting sleep, consequences of insufficient sleep and satisfaction with life in Norwegian adolescents, stratified by sex and by adherence to the 8-hour sleep recommendation, and to examine potential associations between adherence to the 8-hours sleep recommendation and satisfaction with life. Methods: This is a cross-sectional study using data from the Norwegian Ungdata Survey, collected in 2021. Adolescents from five Norwegian counties were included, comprising a total of 32,161 upper secondary school students. Study variables were collected through an electronic questionnaire administered during school hours and all data are anonymous. Descriptive data of sleep patterns are presented, and linear regressions were conducted adjusting for SES, perceived stress, physical activity level, over-the-counter analgesics use, grade level and screen time. Results: 73% of adolescents did not adhere to the 8-hours of sleep recommendation per night, with similar results for girls and boys. 64% reported tiredness at school (minimum 1–2 days weekly) and 62% reported that screen time negatively affected their ability to sleep. 23% reported that gaming affected their sleep, with a higher prevalence in boys than girls. Satisfaction with life score was 7.0 ± 1.9 points (out of 10) for the total sample, with higher scores for boys (7.3 ± 1.8 points) than girls (6.9 ± 1.9 points). Regressions revealed a positive association with satisfaction with life (B = 0.31, 95% [0.15 to 0.48]) in adolescents adhering to sleep recommendation of 8h compared to the ones not adhering to the sleep recommendation. Conclusions: Most Norwegian adolescents fail to adhere to the 8-hours of sleep recommendation and the majority feel tired at school or during activities. More than half of adolescents reported that screen time negatively affected their ability to sleep. Adhering to the sleep recommendation was associated with higher life satisfaction. Our findings highlight the importance of sufficient sleep in adolescents, while future research is needed to examine other sleep related measures on adolescents´ satisfaction with life.

• Bonilla, Diego; Stout, Jeffrey; Candow, Darren G; Jimenez-Garcia, Jose; Gomez-Miranda, Luis & Ortiz-Ortiz, Melinna [Show all 10 contributors for this article] (2024). The power of creatine plus resistance training for healthy aging: enhancing physical vitality and cognitive function. Frontiers in Physiology. 15. doi: 10.3389/fphys.2024.1496544. Full text in Research Archive
• Zanini, Dragana; Todorovic, Nikola & Ostojic, Sergej (2024). Creatine with guanidinoacetic acid improves prefrontal brain oxygenation before, during, and after a cognitive task: A randomized controlled pilot trial. Nutrition and Health. ISSN 0260-1060. doi: 10.1177/02601060241300236. Full text in Research Archive
• Baltic, Sonja; Grasaas, Erik & Ostojic, Sergej (2024). Creatine and sleep habits and disorders in the general population aged 16 years and over: NHANES 2007-2008. Nutrition and Health. ISSN 0260-1060. doi: 10.1177/02601060241299958. Full text in Research Archive
• Ostojic, Sergej (2024). Establishing Reference Intakes for Creatine in Infants Aged 0 to 12 Months. Nutrition reviews. ISSN 0029-6643. 83(7). doi: 10.1093/nutrit/nuae124. Full text in Research Archive
• Ostojic, Sergej (2024). Assessing dietary creatine intake in population studies: challenges and opportunities. Nutrition reviews. ISSN 0029-6643. doi: 10.1093/nutrit/nuae155. Full text in Research Archive
• Baltic, Sonja; Nedeljkovic, David; Todorovic, Nikola; Ratgeber, Laszlo; Betlehem, Jozsef & Pongrac, Acs [Show all 8 contributors for this article] (2024). The Impact of Short-Term Supplementation With Guanidinoacetic Acid and Creatine Versus Creatine Alone on Body Composition Indices in Healthy Men and Women: Creatine-Guanidinoacetic Acid Affects Body Composition. Journal of Nutrition and Metabolism. ISSN 2090-0724. 2024(1). doi: 10.1155/2024/7815807. Full text in Research Archive Show summary

  The main objective of this pilot study was to compare the effects of short-term supplementation with a mixture containing creatine and guanidinoacetic acid (GAA) versus creatine alone on body composition indices in men and women. Twenty-three apparently healthy young adults (mean age: 21.4 ± 0.6 years; 10 females) were randomly assigned to receive either a mixture (consisting of 2 g of creatine monohydrate and 2 g of GAA) or an equimolar amount of creatine monohydrate in a pretest–posttest control group experimental crossover design. After the intervention period, participants entered a 2-week washout phase to minimize any residual effects of the treatment. Body composition was assessed using a multifrequency bioelectrical impedance analysis at baseline (preadministration) and at the 7-day follow-up (postadministration). A significant interaction effect was found for extracellular mass (p = 0.009), with creatine–GAA outperforming creatine in augmenting extracellular mass across the whole sample. In the male subsample, creatine was superior to the mixture in increasing intracellular water (p = 0.049), whereas the mixture increased extracellular mass, contrasting with the reduction observed with creatine alone (p = 0.008). No significant differences between interventions were reported in the female subsample (p > 0.05), indicating that adding GAA to creatine may produce unique, sex-specific effects on body composition. Further studies are needed to validate our findings across different demographic cohorts and various interventional regimens.

• Ostojic, Sergej; Phelps, Nowell H.; Singleton, Rosie K.; Zhou, Bin; Heap, Rachel & Mishra, Anu [Show all 54 contributors for this article] (2024). Worldwide trends in the underweight and obesity from 1990 to 2022: a pooled analysis of 3,633 population-representative studies with 222 million school-aged children, adolescents, and adults. The Lancet. ISSN 0140-6736. 403(10431), p. 1027–1050. doi: 10.1016/S0140-6736(23)02750-2. Full text in Research Archive Show summary

  Background Underweight and obesity are associated with adverse health outcomes throughout the life course. We estimated the individual and combined prevalence of underweight or thinness and obesity, and their changes, from 1990 to 2022 for adults and school-aged children and adolescents in 200 countries and territories. Methods We used data from 3663 population-based studies with 222 million participants that measured height and weight in representative samples of the general population. We used a Bayesian hierarchical model to estimate trends in the prevalence of different BMI categories, separately for adults (age ≥20 years) and school-aged children and adolescents (age 5–19 years), from 1990 to 2022 for 200 countries and territories. For adults, we report the individual and combined prevalence of underweight (BMI <18·5 kg/m2) and obesity (BMI ≥30 kg/m2). For school-aged children and adolescents, we report thinness (BMI <2 SD below the median of the WHO growth reference) and obesity (BMI >2 SD above the median). Findings From 1990 to 2022, the combined prevalence of underweight and obesity in adults decreased in 11 countries (6%) for women and 17 (9%) for men with a posterior probability of at least 0·80 that the observed changes were true decreases. The combined prevalence increased in 162 countries (81%) for women and 140 countries (70%) for men with a posterior probability of at least 0·80. In 2022, the combined prevalence of underweight and obesity was highest in island nations in the Caribbean and Polynesia and Micronesia, and countries in the Middle East and north Africa. Obesity prevalence was higher than underweight with posterior probability of at least 0·80 in 177 countries (89%) for women and 145 (73%) for men in 2022, whereas the converse was true in 16 countries (8%) for women, and 39 (20%) for men. From 1990 to 2022, the combined prevalence of thinness and obesity decreased among girls in five countries (3%) and among boys in 15 countries (8%) with a posterior probability of at least 0·80, and increased among girls in 140 countries (70%) and boys in 137 countries (69%) with a posterior probability of at least 0·80. The countries with highest combined prevalence of thinness and obesity in school-aged children and adolescents in 2022 were in Polynesia and Micronesia and the Caribbean for both sexes, and Chile and Qatar for boys. Combined prevalence was also high in some countries in south Asia, such as India and Pakistan, where thinness remained prevalent despite having declined. In 2022, obesity in school-aged children and adolescents was more prevalent than thinness with a posterior probability of at least 0·80 among girls in 133 countries (67%) and boys in 125 countries (63%), whereas the converse was true in 35 countries (18%) and 42 countries (21%), respectively. In almost all countries for both adults and school-aged children and adolescents, the increases in double burden were driven by increases in obesity, and decreases in double burden by declining underweight or thinness. Interpretation The combined burden of underweight and obesity has increased in most countries, driven by an increase in obesity, while underweight and thinness remain prevalent in south Asia and parts of Africa. A healthy nutrition transition that enhances access to nutritious foods is needed to address the remaining burden of underweight while curbing and reversing the increase in obesity.

• Arndt, Michael Benjamin; Abate, Yohannes Habtegiorgis; Abbasi-Kangevari, Mohsen; ElHafeez, Samar Abd; Abdelmasseh, Michael  & Abd-Elsalam, Sherief [Show all 50 contributors for this article] (2024). Global, regional, and national progress towards the 2030 global nutrition targets and forecasts to 2050: a systematic analysis for the Global Burden of Disease Study 2021. The Lancet. ISSN 0140-6736. 404(10471), p. 2543–2583. doi: 10.1016/S0140-6736(24)01821-X. Full text in Research Archive
• Andjelic, Bogdan; Todorovic, Nikola; Panic, Jovana; Vranes, Milan & Ostojic, Sergej (2024). Video Gaming Reduces Circulating Creatine Levels in Young Male E-Gamers. Journal of Clinical Endocrinology and Metabolism (JCEM). ISSN 0021-972X. 14(1), p. 59–62. doi: 10.14740/jem923. Full text in Research Archive
• Ostojic, Sergej & Vranes, Milan (2024). Molecular hydrogen content of different dietary supplements. Czech Journal of Food Sciences. ISSN 1212-1800. 42(2), p. 136–140. doi: 10.17221/16/2024-CJFS. Full text in Research Archive
• Baltic, Sonja; Nedeljkovic, David; Todorovic, Nikola; Ranisavljev, Marijana; Korovljev, Darinka & Cvejic, Jelena [Show all 11 contributors for this article] (2024). The impact of six-week dihydrogen-pyrroloquinoline quinone supplementation on mitochondrial biomarkers, brain metabolism, and cognition in elderly individuals with mild cognitive impairment: a randomized controlled trial. The Journal of Nutrition, Health & Aging. ISSN 1279-7707. 28(8). doi: 10.1016/j.jnha.2024.100287. Full text in Research Archive
• Todorovic, N. & Ostojic, Sergej (2024). Recent advances in hydrogen research for exercise science: Modulating circadian rhythm, immunity, and athlete recovery. Science & sports. ISSN 0765-1597. doi: 10.1016/j.scispo.2024.06.002. Full text in Research Archive
• Baltic, Sonja; Grasaas, Erik & Ostojic, Sergej (2024). Dietary creatine and carcinogenic biomarkers in adult population. Nutrition and Health. ISSN 0260-1060. doi: 10.1177/02601060241291694. Full text in Research Archive
• Ostojic, Sergej; Grasaas, Erik; Baltic, Sonja & Cvejic, Jelena (2024). Dietary creatine is associated with lower serum neurofilament light chain levels. Applied Physiology, Nutrition and Metabolism. ISSN 1715-5312. 49(8), p. 1121–1123. doi: 10.1139/apnm-2024-0064. Full text in Research Archive
• Øverby, Nina Cecilie; Hillesund, Elisabet Rudjord; Medin, Anine Christine; Vik, Frøydis Nordgård & Ostojic, Sergej (2023). Nutrition in a lifecourse perspective: From molecular aspects to public health approaches. Maternal & Child Nutrition. ISSN 1740-8695. 20(S2). doi: 10.1111/mcn.13582. Full text in Research Archive
• Ostojic, Sergej; Hillesund, Elisabet Rudjord; Øverby, Nina Cecilie; Vik, Frøydis Nordgård & Medin, Anine Christine (2023). Individual nutrients and serum klotho levels in adults aged 40–79 years. Food Science & Nutrition. 11(6), p. 3279–3286. doi: 10.1002/fsn3.3310. Full text in Research Archive Show summary

  Several dietary factors (including adherence to the Mediterranean diet or higher nut intake) seem to positively affect circulating antiaging Klotho protein levels; yet, a description of possible relationships between individual nutrients and Klotho activity has not been evaluated. We analyzed the association of dietary intake of individual macro- and micronutrients and nonnutritive food components with circulating Klotho levels in a sample of 40- to 79-year-old US adults. Data from the 2015–2016 National Health and Nutrition Examination Survey were analyzed. Nutrient/food component intakes were calculated in relation to total energy intake using the nutrient density method, and available pristine serum samples were analyzed for serum Klotho concentrations. The final study sample consisted of 2637 participants (mean age 59.0 ± 10.7 years; 52% women). Higher Klotho concentrations were found with higher intake of carbohydrates (p < .001), total sugars (p < .001), dietary fibers (p < .001), vitamin D (p = .05), total folates (p = .015), and copper (p = .018). The results of the regression analysis with a crude model showed significant associations among five nutrients/food components (carbohydrates, alcohol, total sugars, dietary fibers, and niacin) and soluble Klotho levels across the sample. After adjusting the models for age and gender, the nutrient/food component–Klotho association remained significant for carbohydrates, total sugars, and alcohol (p < .05). Dietary exposure to individual nutrients and nonnutritive food components appears to be associated with Klotho activity; however, additional research is needed to investigate the relationship between cause and effect in diet composition–Klotho interplay.

• Ranisavljev, Marijana; Todorovic, Nikola; Panic, Jovana; Andjelic, Bogdan; Vranes, Milan & Ostojic, Sergej (2023). Short-term fasting affects biomarkers of creatine metabolism in healthy men and women. Human Nutrition & Metabolism. ISSN 2666-1497. 34. doi: 10.1016/j.hnm.2023.200217. Full text in Research Archive
• Korovljev, Darinka; Ostojic, Jelena; Todorovic, Nikola & Ostojic, Sergej (2023). Molecular hydrogen modulates brain glutamate/ GABA-glutamine cycle in overweight humans. Archives of Medical Science. ISSN 1734-1922. 19(4), p. 1151–1153. doi: 10.5114/aoms/162938. Full text in Research Archive Show summary

  Introduction: We evaluated whether 12-week intake of molecular hydrogen (H2 ) in 5 overweight adults (3 women; age: 50.2 ±11.9 years, body mass index: 29.4 ±2.1 kg/m2 ) affects brain levels of the glutamate-glutamine-GABA cycle, critical amino acid neurotransmitters in the mechanism of neuronal activation during appetite regulation. Methods: A 1.5-T single-voxel proton magnetic resonance spectroscopy was used to assess the tissue concentrations of relevant metabolites. Results: The mean glutamate and glutamate-plus-glutamine levels at the posterior cingulate gyrus decreased significantly during the study; this was accompanied by a significant drop in GABA levels at left prefrontal white matter, and glutathione levels at anterior cingulate gyrus. No changes in the brain metabolites were found in the comparable group of overweight individuals (n = 4, 2 women; age: 41.0 ±13.9, BMI 26.8 ±1.3 kg/m2 ) followed-up in the past without this treatment. Conclusions: We showed a possible hydrogen-driven upregulation of neurotransmitters involved in appetite stimulation leading to hunger suppression and weight loss. Further studies analyzing appetite-controlling metabolic pathways affected by H2 would require monitoring of additional biomarkers of satiation and satiety during different feeding regimens.

• Ostojic, Sergej; Ratgeber, Laszlo; Trunic, Nenad & Rajkovic, Sava (2023). Cataloguing guanidinoacetic acid content in nutritional supplements. Food Science & Nutrition. 11(4), p. 1603–1605. doi: 10.1002/FSN3.3206. Full text in Research Archive Show summary

  Guanidinoacetic acid (GAA, also known as glycocyamine or guanidinoacetate) is a naturally occurring alpha amino acid derivative and newly recognized dietary compound obtainable by different foods and nutritional supplements. Anecdotal evidence suggests that the GAA exposure from supplements might be a major source of GAA supply, out-competing other food sources for several orders of magnitude. This original technical paper summarizes information about GAA levels in different nutritional supplements, as derived from the U.S. National Institutes of Health dietary supplement database.

• Candow, Darren G.; Prokopidis, Konstantinos; Forbes, Scott C.; Rusterholz, Flavia; Campbell, Bill I. & Ostojic, Sergej (2023). Resistance Exercise and Creatine Supplementation on Fat Mass in Adults < 50 Years of Age: A Systematic Review and Meta-Analysis. Nutrients. 15(20). doi: 10.3390/nu15204343. Full text in Research Archive Show summary

  The combination of resistance exercise and creatine supplementation has been shown to decrease body fat percentage in adults ≥ 50 years of age. However, the effect on adults < 50 years of age is currently unknown. To address this limitation, we systematically reviewed the literature and performed several meta-analyses comparing studies that included resistance exercise and creatine supplementation to resistance exercise and placebo on fat mass and body fat percentage Twelve studies were included, involving 266 participants. Adults (<50 years of age) who supplemented with creatine and performed resistance exercise experienced a very small, yet significant reduction in body fat percentage (−1.19%, p = 0.006); however, no difference was found in absolute fat mass (−0.18 kg, p = 0.76). Collectively, in adults < 50 years of age, the combination of resistance exercise and creatine supplementation produces a very small reduction in body fat percentage without a corresponding decrease in absolute fat mass.

• Todorovic, Nikola & Ostojic, Sergej (2023). Reconsidering molecular hydrogen deficits: A potential target for intervention? Medical Hypotheses. ISSN 0306-9877. 177. doi: 10.1016/j.mehy.2023.111116. Full text in Research Archive Show summary

  Molecular hydrogen (H2, dihydrogen) is considered an antioxidant and signaling molecule that possesses potent antioxidative, antiapoptotic, and anti-inflammatory properties. Despite the growing interest in H2 as a potential therapeutic agent, there is a scarcity of fundamental studies on dihydrogen and limited knowledge regarding its effects on cellular health and function. In this paper, we propose a hypothesis concerning the potential link between H2 shortage and overall health status. The primary objective is to address two critical questions: first, what is the overall significance of H2 levels in maintaining optimal cellular function, and second, whether specific health conditions are associated with H2 deficiencies. Further validation is necessary to establish the relationship between H2 levels and health, yet the growing body of evidence indicates that disturbances in H2 turnover may have a modulatory effect on immune function, homeostasis, and the development of neurodegenerative diseases.

• Mishra, Anu; Zhou, Bin; Rodriguez-Martinez, Andrea; Bixby, Honor; Singleton, Rosie K. & Carrillo-Larco, Rodrigo M. [Show all 1,626 contributors for this article] (2023). Diminishing benefits of urban living for children and adolescents’ growth and development. Nature. ISSN 0028-0836. 615(7954), p. 874–883. doi: 10.1038/s41586-023-05772-8. Full text in Research Archive Show summary

  Optimal growth and development in childhood and adolescence is crucial for lifelong health and well-being1,2,3,4,5,6. Here we used data from 2,325 population-based studies, with measurements of height and weight from 71 million participants, to report the height and body-mass index (BMI) of children and adolescents aged 5–19 years on the basis of rural and urban place of residence in 200 countries and territories from 1990 to 2020. In 1990, children and adolescents residing in cities were taller than their rural counterparts in all but a few high-income countries. By 2020, the urban height advantage became smaller in most countries, and in many high-income western countries it reversed into a small urban-based disadvantage. The exception was for boys in most countries in sub-Saharan Africa and in some countries in Oceania, south Asia and the region of central Asia, Middle East and north Africa. In these countries, successive cohorts of boys from rural places either did not gain height or possibly became shorter, and hence fell further behind their urban peers. The difference between the age-standardized mean BMI of children in urban and rural areas was <1.1 kg m–2 in the vast majority of countries. Within this small range, BMI increased slightly more in cities than in rural areas, except in south Asia, sub-Saharan Africa and some countries in central and eastern Europe. Our results show that in much of the world, the growth and developmental advantages of living in cities have diminished in the twenty-first century, whereas in much of sub-Saharan Africa they have amplified.

• Korovljev, Darinka; Javorac, Dejan; Todorovic, Nikola; Ranisavljev, Marijana; Engeset, Dagrun & Stea, Tonje Holte [Show all 15 contributors for this article] (2023). The Effects of 12-Week Hydrogen-Rich Water Intake on Body Composition, Short-Chain Fatty Acids Turnover, and Brain Metabolism in Overweight Adults: A Randomized Controlled Trial. Current Topics in Nutraceuticals Research. ISSN 1540-7535. 21(3), p. 235–241. doi: 10.37290/235-241. Full text in Research Archive Show summary

  The aim of this randomized controlled trial was to analyze the effects of medium-term supplementation with hydrogen-rich water on brain metabolism, appetite-regulating hormones, body composition, and safety biomarkers in overweight adults. Twenty (n = 20, 10 females) apparently healthy adults with a body mass index >24.9 kg/m2 were assigned to receive 0.5 L per day of hydrogen-rich water (7.5 mg of hydrogen) or hydrogen-free water (tap water) for 12 weeks. Two-way analysis of variance with repeated measures revealed a significant difference between the two interventions in several body composition indices (P ≤ 0.05), with hydrogen-rich water superior to placebo to reduce waist circumference and mid-upper arm circumference by 1.31 cm (95% confidence interval, from –0.23 to 2.85) and 0.65 cm (95% confidence interval, from –0.10 to 1.40), respectively. Hydrogen-rich water outcompeted placebo to raise serum ghrelin levels, as the mean difference from the placebo group was 17.28 pmol/L (95% confidence interval, from 1.81 to 32.75) (P = 0.02). A non-significant strong positive trend (P = 0.10) was reported toward hydrogen-rich water being superior to placebo in augmenting total serum short-chain fatty acid levels, with a mean difference from the control group of 195.6 μmol/L (95% confidence interval, from –64.55 to 275.85). The mean fecal calprotectin levels were significantly reduced after hydrogen-rich water intervention for 19.7 μg/mg (95% confidence interval, from 0.31 to 39.09) (P = 0.03). Our findings advance hydrogen-rich water as a promising metabolic intervention in overweight adults, but further validation via multicentric longitudinal randomized controlled trials in metabolic and nutritional disorders is required.

• Stajer, Valdemar; Todorovic, Nikola; Conic, Branislava Srdenovic; Kladar, Nebojsa; Engeset, Dagrun & Stea, Tonje Holte [Show all 12 contributors for this article] (2023). The Effects of Medium-Term Intake of Hydrogen-Rich Water on Sperm Quality Biomarkers in Normospermic and Oligospermic Men: A Randomized Controlled Pilot Trial. Current Topics in Nutraceuticals Research. ISSN 1540-7535. 21(2), p. 182–186. doi: 10.37290/182-186. Full text in Research Archive
• Ostojic, Sergej; Grasaas, Erik & Jelena, Cvejic (2023). Dietary creatine and cancer risk in the U.S. population: NHANES 2017–2020. Journal of Functional Foods. ISSN 1756-4646. 108. doi: 10.1016/j.jff.2023.105733. Full text in Research Archive Show summary

  While creatine is generally considered a safe dietary compound, there have been concerns about excessive creatine intake and its possible link to cancer. The main of this study was to examine the relationship between dietary creatine intake and cancer risk in the general US population using data from the 2017–2020 National Health and Nutrition Examination Survey (NHANES). We extracted a dataset that included information on medical conditions and dietary intake from 7,344 NHANES respondents. We used individual data files containing detailed information about each food and beverage item consumed to calculate creatine intake from meat- and milk-based food sources. In a subset of NHANES respondents who reported their cancer status, the average daily creatine intake was 11.6 ± 11.5 mg per kg body mass (95 % CI, 11.3 to 11.8); all participants in the subset were 20 years or older. Cancer-free individuals consumed significantly more creatine per day than those with cancer (11.7 ± 11.6 mg/kg body mass vs. 10.6 ± 10.2 mg/kg body mass; P = 0.01). The odds ratio for having cancer in the subset of participants consuming < 10.5 mg of creatine per kg body mass daily (the 50th percentile of consumption) compared to those with higher intake (≥10.5 mg) was 1.18 (95 % CI, from 1.01 to 1.37), indicating a significant association between lower dietary creatine intake and increased cancer risk (P = 0.03). Our findings suggest that consuming a diet that includes more creatine may be associated with a reduced risk of cancer or malignancy in U.S. adults aged 20 years and over, with the average difference in creatine intake between cancer-free individuals and cancer groups was relatively small (1.1 mg/kg body mass). Further studies are necessary to confirm the potential benefits of creatine-rich foods or dietary supplements in the management of cancer.

• Candow, Darren G.; Forbes, Scott C.; Ostojic, Sergej; Prokopidis, Konstantinos; Stock, Matt S. & Harmon, Kylie K. [Show all 7 contributors for this article] (2023). “Heads Up” for Creatine Supplementation and its Potential Applications for Brain Health and Function. Sports Medicine. ISSN 0112-1642. doi: 10.1007/s40279-023-01870-9. Full text in Research Archive Show summary

  There is emerging interest regarding the potential beneficial effects of creatine supplementation on indices of brain health and function. Creatine supplementation can increase brain creatine stores, which may help explain some of the positive effects on measures of cognition and memory, especially in aging adults or during times of metabolic stress (i.e., sleep deprivation). Furthermore, creatine has shown promise for improving health outcome measures associated with muscular dystrophy, traumatic brain injury (including concussions in children), depression, and anxiety. However, whether any sex- or age-related differences exist in regard to creatine and indices of brain health and function is relatively unknown. The purpose of this narrative review is to: (1) provide an up-to-date summary and discussion of the current body of research focusing on creatine and indices of brain health and function and (2) discuss possible sex- and age-related differences in response to creatine supplementation on brain bioenergetics, measures of brain health and function, and neurological diseases.

• Ostojic, Sergej & Jorga, Jagoda (2023). Guanidinoacetic acid in human nutrition: Beyond creatine synthesis. Food Science & Nutrition. 11(4), p. 1606–1611. doi: 10.1002/fsn3.3201. Full text in Research Archive Show summary

  Guanidinoacetic acid (GAA) is a nutrient that has been used in human nutrition since the early 1950s. Recommended for its role in creatine biosynthesis, GAA demonstrated beneficial energy-boosting effects in various clinical conditions. Dietary GAA has also been suggested to trigger several creatine-independent mechanisms. Besides acting as a direct precursor of high-energy phosphagen creatine, dietary GAA is suggested to reduce blood glucose concentration by acting as an insulinotropic food compound, spare amino acid arginine for other metabolic purposes (including protein synthesis), modulate taste, and perhaps alter methylation and fat deposition in various organs including the liver. GAA as a food component can have several important metabolic roles beyond creatine biosynthesis; future studies are highly warranted to address GAA overall role in human nutrition.

• Slankamenac, Jelena; Ranisavljev, Marijana; Todorovic, Nikola; Ostojic, Jelena; Stajer, Valdemar & Ostojic, Sergej (2023). Effects of six-month creatine supplementation on patient- and clinician-reported outcomes, and tissue creatine levels in patients with post-COVID-19 fatigue syndrome. Food Science & Nutrition. doi: 10.1002/fsn3.3597. Full text in Research Archive Show summary

  Dietary creatine has been recently put forward as a possible intervention strategy to reduce post-COVID-19 fatigue syndrome yet no clinical study so far evaluated its efficacy and safety for this perplexing condition. In this parallel-group, randomized placebo-controlled double-blind trial, we analyzed the effects of 6-month creatine supplementation (4 g of creatine monohydrate per day) on various patient- and clinician-reported outcomes, and tissue creatine levels in 12 patients with post-COVID-19 fatigue syndrome. Creatine intake induced a significant increase in tissue creatine levels in vastus medialis muscle and right parietal white matter compared to the baseline values at both 3-month and 6-month follow-ups (p < .05). Two-way analysis of variance with repeated measures revealed a significant difference (treatment vs. time interaction) between interventions in tissue creatine levels (p < .05), with the creatine group was superior to placebo to augment creatine levels at vastus medialis muscle, left frontal white matter, and right parietal white matter. Creatine supplementation induced a significant reduction in general fatigue after 3 months of intake compared to baseline values (p = .04), and significantly improved scores for several post-COVID-19 fatigue syndrome-related symptoms (e.g., ageusia, breathing difficulties, body aches, headache, and difficulties concentrating) at 6-month follow-up (p < .05). Taking creatine for 6 months appears to improve tissue bioenergetics and attenuate clinical features of post-COVID-19 fatigue syndrome; additional studies are warranted to confirm our findings in various post-COVID-19 cohorts.

• Korovljev, Darinka; Todorovic, Nikola; Ranisavljev, Marijana; Andjelic, Bogdan; Kladar, Nebojsa & Stajer, Valdemar [Show all 7 contributors for this article] (2023). Hydrogen-rich water upregulates fecal propionic acid levels in overweight adults. Nutrition - The International Journal of Applied and Basic Nutritional Sciences. ISSN 0899-9007. 116. doi: 10.1016/j.nut.2023.112200. Full text in Research Archive
• Momtazmanesh, Sara; Moghaddam, Sahar Saeedi; Ghamari, Seyyed-Hadi; Rad, Elaheh Malakan; Rezaei, Negar & Shobeiri, Parnian [Show all 50 contributors for this article] (2023). Global burden of chronic respiratory diseases and risk factors, 1990–2019: an update from the Global Burden of Disease Study 2019. EClinicalMedicine. 59. doi: 10.1016/j.eclinm.2023.101936. Full text in Research Archive Show summary

  Background Updated data on chronic respiratory diseases (CRDs) are vital in their prevention, control, and treatment in the path to achieving the third UN Sustainable Development Goals (SDGs), a one-third reduction in premature mortality from non-communicable diseases by 2030. We provided global, regional, and national estimates of the burden of CRDs and their attributable risks from 1990 to 2019. Methods Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we estimated mortality, years lived with disability, years of life lost, disability-adjusted life years (DALYs), prevalence, and incidence of CRDs, i.e. chronic obstructive pulmonary disease (COPD), asthma, pneumoconiosis, interstitial lung disease and pulmonary sarcoidosis, and other CRDs, from 1990 to 2019 by sex, age, region, and Socio-demographic Index (SDI) in 204 countries and territories. Deaths and DALYs from CRDs attributable to each risk factor were estimated according to relative risks, risk exposure, and the theoretical minimum risk exposure level input. Findings In 2019, CRDs were the third leading cause of death responsible for 4.0 million deaths (95% uncertainty interval 3.6–4.3) with a prevalence of 454.6 million cases (417.4–499.1) globally. While the total deaths and prevalence of CRDs have increased by 28.5% and 39.8%, the age-standardised rates have dropped by 41.7% and 16.9% from 1990 to 2019, respectively. COPD, with 212.3 million (200.4–225.1) prevalent cases, was the primary cause of deaths from CRDs, accounting for 3.3 million (2.9–3.6) deaths. With 262.4 million (224.1–309.5) prevalent cases, asthma had the highest prevalence among CRDs. The age-standardised rates of all burden measures of COPD, asthma, and pneumoconiosis have reduced globally from 1990 to 2019. Nevertheless, the age-standardised rates of incidence and prevalence of interstitial lung disease and pulmonary sarcoidosis have increased throughout this period. Low- and low-middle SDI countries had the highest age-standardised death and DALYs rates while the high SDI quintile had the highest prevalence rate of CRDs. The highest deaths and DALYs from CRDs were attributed to smoking globally, followed by air pollution and occupational risks. Non-optimal temperature and high body-mass index were additional risk factors for COPD and asthma, respectively. Interpretation Albeit the age-standardised prevalence, death, and DALYs rates of CRDs have decreased, they still cause a substantial burden and deaths worldwide. The high death and DALYs rates in low and low-middle SDI countries highlights the urgent need for improved preventive, diagnostic, and therapeutic measures. Global strategies for tobacco control, enhancing air quality, reducing occupational hazards, and fostering clean cooking fuels are crucial steps in reducing the burden of CRDs, especially in low- and lower-middle income countries.

• Todorovic, Nikola; Fernández-Landa, Julen; Santibañez, Asier; Kura, Branislav; Stajer, Valdemar & Korovljev, Darinka [Show all 7 contributors for this article] (2023). The Effects of Hydrogen-Rich Water on Blood Lipid Profiles in Clinical Populations: A Systematic Review and Meta-Analysis. Pharmaceuticals. 16(2). doi: 10.3390/ph16020142. Full text in Research Archive Show summary

  Over the last two decades, a plethora of disease models and human studies have confirmed the beneficial effects of molecular hydrogen (H2), a simple biotherapeutic gas. Recent small-scale studies evaluating the effects of hydrogen-rich water (HRW) on various metabolic conditions pointed to advantageous effects of HRW in regulating blood lipid profiles. However, to the best of the authors’ knowledge, no systematic review and/or meta-analysis (SRMA) were published considering HRW consumption and lipid/lipoprotein status. Therefore, the aim of this SRMA was to assess the effects of HRW consumption on blood lipid panel in clinical populations. The search strategy was designed using PRISMA guidelines, and the databases PubMed/Medline, Web of Science, and Scopus were explored from inception until 4 October 2022. A total of seven studies satisfied all the eligibility criteria and were included in SRMA. The results for the pooled meta-analysis showed a significant reduction in total cholesterol, low-density lipoprotein, and triglycerides after HRW intake (p = 0.01), with small to moderate effects (pooled SMD = −0.23 (from −0.40 to 0.05); pooled SMD = −0.22 (from −0.39 to 0.04); pooled SMD = −0.38 (from −0.59 to 0.18), respectively). Our findings indicate that drinking HRW can significantly improve lipid status in the clinical populations. Additional studies are warranted to further validate this connection.

• Ostojic, Sergej; Ratgeber, Laszlo; Betlehem, Jozsef & Acs, Pongrac (2023). Molecular nutrition in life course perspective: Pinpointing metabolic pathways to target during periconception. Maternal & Child Nutrition. ISSN 1740-8695. 20(52). doi: 10.1111/mcn.13474. Full text in Research Archive Show summary

  Lifecourse nutrition encompasses nourishment from early development into parenthood. From preconception and pregnancy to childhood, late adolescence, and reproductive years, life course nutrition explores links between dietary exposures and health outcomes in current and future generations from a public health perspective, usually addressing lifestyle behaviours, reproductive well-being and maternal-child health strategies. However, nutritional factors that play a role in conceiving and sustaining new life might also require a molecular perspective and recognition of critical interactions between specific nutrients and relevant biochemical pathways. The present perspective summarises evidence about the links between diet during periconception and next-generation health and outlines the main metabolic networks involved in nutritional biology of this sensitive time frame.

• Fernández-Landa, Julen; Santibañez-Gutierrez, Asier; Todorovic, Nikola; Stajer, Valdemar & Ostojic, Sergej (2023). Effects of Creatine Monohydrate on Endurance Performance in a Trained Population: A Systematic Review and Meta-analysis. Sports Medicine. ISSN 0112-1642. 53(5), p. 1017–1027. doi: 10.1007/s40279-023-01823-2. Full text in Research Archive
• Milovancev, Aleksandra; Avakumovic, Jovana; Drid, Patrik; Todorovic, Nikola; Stajer, Valdemar & Ostojic, Sergej (2022). Hydrogen-rich water alleviates inflammation and fatigue in COVID-19: A pilot study. European Journal of Inflammation. ISSN 1721-727X. 20. doi: 10.1177/1721727X221094197. Full text in Research Archive
• Ostojic, Sergej (2022). Malproduction of endogenous hydrogen gas in COVID-19. Frontiers in Cellular and Infection Microbiology. 12. doi: 10.3389/fcimb.2022.924832. Full text in Research Archive
• Todorovic, Nikola; Korovljev, Darinka; Stajer, Valdemar; Jorga, Jagoda & Ostojic, Sergej (2022). Creatine consumption and liver disease manifestations in individuals aged 12 years and over. Food Science & Nutrition. doi: 10.1002/fsn3.3151. Full text in Research Archive
• Forbes, Scott C; Cordingley, Dean; Cornish, Stephen; Gualano, Bruno; Roschel, Hamilton & Ostojic, Sergej [Show all 11 contributors for this article] (2022). Effects of Creatine Supplementation on Brain Function and Health. Nutrients. 14(5). doi: 10.3390/nu14050921. Full text in Research Archive Show summary

  While the vast majority of research involving creatine supplementation has focused on skeletal muscle, there is a small body of accumulating research which has focused on creatine and the brain. Preliminary studies indicate that creatine supplementation (and guanidinoacetic acid; GAA) has the ability to increase brain creatine content in humans. Further, creatine has shown some promise for attenuating symptoms of concussion, mild traumatic brain injury and depression but its effect on neurodegenerative diseases appears lacking. The purpose of this narrative review is to summarize the current body of research pertaining to creatine supplementation on total creatine and phophorylcreatine content, explore GAA as an alternative or adjunct to creatine supplementation on brain creatine uptake, assess the impact of creatine on cognition with a focus on sleep deprivation, discuss the effects of creatine supplementation on a variety of neurological and mental health conditions, and outline recent advances on creatine supplementation as a neuroprotective supplement following traumatic brain injury or concussions.

• Ostojic, Sergej (2022). Guanidinoacetic Acid as a Nutritional Adjuvant to Multiple Sclerosis Therapy. Frontiers in Human Neuroscience. 16. doi: 10.3389/fnhum.2022.871535. Full text in Research Archive
• Ostojic, Sergej; Ostojic, Jelena; Zanini, Dragana; Jezdimirovic, Tatjana & Stajer, Valdemar (2022). Guanidinoacetate–creatine in secondary progressive multiple sclerosis: a case report. Journal of International Medical Research. ISSN 0300-0605. 50(1), p. 1–5. doi: 10.1177/03000605211073305. Full text in Research Archive Show summary

  Acute secondary progressive multiple sclerosis (SPMS) is characterized by escalating neurological disability, with limited disease-modifying therapeutic options. A 48-year-old woman with acute SPMS being treated with interferon beta-1a and oral corticosteroids presented as a clinical out- patient with no disease-modifying effects after treatment. A decision was made to treat her with a combination of guanidinoacetate and creatine for 21 days. She had made clinical progress at follow-up, with the intensity of fatigue dropping from severe to mild. Magnetic resonance spec- troscopy revealed increased brain choline, creatine, N-acetylaspartate, and glutathione. Patients with SPMS may benefit from guanidinoacetate–creatine treatment in terms of patient- and clinician-reported outcomes; this requires additional study.

• Ostojic, Sergej (2022). Low tissue creatine: a therapeutic target in clinical nutrition. Nutrients. 14(6). doi: 10.3390/nu14061230. Full text in Research Archive Show summary

  Low tissue creatine characterizes many conditions, including neurodegenerative, cardiopulmonary, and metabolic diseases, with a magnitude of creatine shortfall often corresponds well to a disorder’s severity. A non-invasive monitoring of tissue metabolism with magnetic resonance spectroscopy (MRS) might be a feasible tool to evaluate suboptimal levels of creatine for both predictive, diagnostic, and therapeutic purposes. This mini-review paper summarizes disorders with deficient creatine levels, and provides arguments for assessing and employing tissue creatine as a relevant target in clinical nutrition.

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• Nedeljkovic, David; Todorovic, Nikola; Stea, Tonje Holte; Engeset, Dagrun & Ostojic, Sergej (2025). Association between dietary creatine intake and serum biomarkers of spermatogenesis in males aged 12 years and older. doi: 10.1530/raf-25-0009. Full text in Research Archive Show summary

  Creatine is a nutrient that helps provide energy to different parts of the body, including the testes. Since making sperm takes a lot of energy, creatine might play a role in supporting sperm health. Some studies suggest it could help, while others raise concerns. However, it is still unclear what effect, if any, creatine from food has on sperm. To learn more, we looked at data from over 1,300 males in the US, aged 12 and older. We compared how much creatine they got from their diet with levels of two hormones in the blood that are related to sperm production. We found no strong link between dietary creatine and these hormone levels. This suggests that creatine from food probably does not have a major effect – good or bad – on male reproductive health. Since this study used existing data and did not test creatine directly in an experiment, we cannot say for sure if creatine causes any changes. More research, especially studies that look directly at sperm, is needed to better understand how creatine might affect fertility.

• Baltic, Sonja; Todorovic, Nikola; Popovic, Sanela; Galic, Vladimir; Semnic, Marija & Ostojic, Sergej (2025). Breath hydrogen levels in patients with Parkinson's disease: A pilot cross-sectional study. Parkinsonism & Related Disorders. ISSN 1353-8020. 133. doi: 10.1016/j.parkreldis.2025.107353. Full text in Research Archive
• Ranisavljev, Marijana; Stajer, Valdemar; Todorovic, Nikola; Ostojic, Jelena; Cvejic, Jelena Helena & Steinert, Robert E. [Show all 7 contributors for this article] (2025). Correction to: The effects of 3-month supplementation with synbiotic on patient-reported outcomes, exercise tolerance, and brain and muscle metabolism in adult patients with post-COVID-19 chronic fatigue syndrome (STOP-FATIGUE): a randomized Placebo-controlled clinical trial (European Journal of Nutrition, (2025), 64, 1, (28), 10.1007/s00394-024-03546-0). European Journal of Nutrition. ISSN 1436-6207. 64(2). doi: 10.1007/s00394-025-03591-3. Full text in Research Archive
• Ostojic, Sergej (2024). Preterm Babies: Predicting the Consequences. Journal of Pediatric Neurology. ISSN 1304-2580. 22(1), p. 85–85. doi: 10.1055/s-0043-1761933. Full text in Research Archive
• Ostojic, Sergej (2024). Creatine metabolism during pregnancy: advancing toward understanding. American Journal of Clinical Nutrition. ISSN 0002-9165. 119(3), p. 591–592. doi: 10.1016/j.ajcnut.2023.12.026. Full text in Research Archive
• Todorovic, Nikola; Javorac, Dejan & Ostojic, Sergej (2024). Comment on: “Can hydrogen prevent stress fractures in athletes?” Exploring the discussion of hydrogen use in sport medicine. Medical Hypotheses. ISSN 0306-9877. 192. doi: 10.1016/j.mehy.2024.111492. Full text in Research Archive
• Candow, Darren G.; Forbes, Scott C.; Ostojic, Sergej; Prokopidis, Konstantinos; Stock, Matt S. & Harmon, Kylie K. [Show all 7 contributors for this article] (2023). Correction to: “Heads Up” for Creatine Supplementation and its Potential Applications for Brain Health and Function (Sports Medicine, (2023), 10.1007/s40279-023-01870-9). Sports Medicine. ISSN 0112-1642. doi: 10.1007/s40279-023-01888-z. Full text in Research Archive
• Ostojic, Sergej; Korovljev, Darinka; Todorovic, Nikola & Stajer, Valdemar (2023). Dietary creatine intake and head circumference among very young U.S. children. Progress in Nutrition. ISSN 1129-8723. 25(1), p. e2023028–e2023028. doi: 10.23751/pn.v25i1.11595. Full text in Research Archive
• Ostojic, Sergej & Øverby, Nina Cecilie (2023). Editorial: Scientific integrity in nutritional research. Frontiers in Nutrition. 10. doi: 10.3389/fnut.2023.1323265. Full text in Research Archive
• Todorovic, Nikola & Ostojic, Sergej (2023). Molecular hydrogen as a potential adjuvant therapy for alleviating long COVID. Medical Hypotheses. ISSN 0306-9877. 180. doi: 10.1016/j.mehy.2023.111188. Full text in Research Archive
• Ostojic, Sergej (2022). Hydrogen-Rich Water as a Dietary Activator of Brown Adipose Tissue and UCP1? Annals of Nutrition and Metabolism. ISSN 0250-6807. 78(4), p. 242–243. doi: 10.1159/000525175. Full text in Research Archive

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