Erythrocyte Omega-3 Fatty Acid Content in Elite Athletes in Response to Omega-3 Supplementation: A Dose-Response Pilot Study

Impact of fish oil supplementation on plasma levels of highly unsaturated fatty acid-containing lipid classes and molecular species in American football athletes

BACKGROUND

Previous studies have linked sports-related concussions and repeated subconcussive head impacts in contact sport athletes to elevated brain injury biomarkers. Docosahexaenoic acid (DHA), the primary omega-3 (n-3) highly unsaturated fatty acid (HUFA) in the brain, has shown neuroprotective effects in animal models after brain injury, but clinical research has shown mixed results.

METHODS

We conducted a randomized, double-blind, placebo-controlled study on 29 Division 1 collegiate American football players, exploring the impact of DHA (2.5 g) and eicosapentaenoic acid (EPA) (1.0 g) supplied as ethyl esters, on levels of plasma lipids shown to cross the blood-brain barrier. Dietary intake data was collected using food frequency questionnaires (FFQ). Complex lipids and unesterified fatty acids were isolated from plasma, separated via reversed-phase liquid chromatography and analyzed by targeted lipidomics analysis.

RESULTS

FFQ results indicated that participants had low dietary n-3 HUFA intake and high omega-6 (n-6):n-3 polyunsaturated fatty acids (PUFA) and HUFA ratios at baseline. After DHA + EPA supplementation, plasma lysophosphatidylcholine (LPC) containing DHA and EPA significantly increased at all timepoints (weeks 17, 21, and 26; p < 0.0001), surpassing placebo at Weeks 17 (p < 0.05) and 21 (p < 0.05). Phosphatidylcholine (PC) molecular species containing DHA or EPA, PC38:6 PC36:6, PC38:7, PC40:6, and PC40:8, increased significantly in the DHA + EPA treatment group at Weeks 17 (and 21. Plasma concentrations of non-esterified DHA and EPA rose post-supplementation in Weeks 17 and 21.

CONCLUSIONS

This study demonstrates that n-3 HUFA supplementation, in the form of ethyl esters, increased the DHA and EPA containing plasma lipid pools the have the capacity to enrich brain lipids and the potential to mitigate the effects of sports-related concussions and repeated subconcussive head impacts.

TRIAL REGISTRATION

All deidentified data are available at ClinicalTrials.gov #NCT0479207.

Omega-3 Status Evaluation in Australian Female Rugby League Athletes: Ad Libitum Fish Oil Provision Results in a Varied Omega-3 Index

Optimal omega-3 status, influenced by increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), is vital for physiological health. This study investigated the impact of ad libitum fish oil supplementation on the omega-3 status of female athletes in a professional rugby league team during a competitive season. Twenty-four (n = 24) athletes participated, and their omega-3 status was assessed using the Omega-3 Index (O3I) and arachidonic acid (AA) to EPA ratio through finger-prick blood samples taken at the start and end of the season. They were given access to a fish oil supplement (PILLAR Performance, Australia) with a recommended daily dose of four capsules per day (2,160 mg EPA and 1,440 mg docosahexaenoic acid). At the beginning of the season, the group mean O3I was 4.77% (95% confidence interval [CI: 4.50, 5.04]) and the AA to EPA ratio was 14.89 (95% CI [13.22, 16.55]). None of the athletes had an O3I exceeding 8%. By the season's end, the O3I was a significantly increased to 7.28% (95% CI [6.64, 7.93], p < .0001) and AA to EPA ratio significantly decreased to a mean of 6.67 (95% CI [5.02, 8.31], p < .0001), driven primarily by the significant increase in EPA of +1.14% (95% CI [0.77, 1.51], p < .0001). However, these changes were varied between the athletes and most likely due to compliance. This study has demonstrated that using the objective O3I feedback scale is possible with elite female rugby athletes, but individual strategies will be required to achieve daily intake targets of EPA + DHA.

Omega-3 Index as a Sport Biomarker: Implications for Cardiovascular Health, Injury Prevention, and Athletic Performance

The composition of polyunsaturated fatty acids (PUFA) in the cell membrane plays a crucial role in cell signaling and function. Physical activity can induce shifts in PUFA metabolism, potentially altering their membrane composition. Given the multifaceted regulatory and structural roles of PUFA, training-related fluctuations in PUFA concentrations may impact health and athletic performance in both elite and non-elite athletes, highlighting the critical role of these fatty acids' nutritional intake. The ω-3 index (O3I), a biomarker reflecting the proportion of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in red blood cell membranes, is considered a marker of cardiovascular risk, gaining increasing interest in sports medicine. Dietary interventions aimed at maintaining an optimal O3I may offer several benefits for elite and non-elite athletes, including cardiovascular health performance optimization, recovery, and injury prevention. Here, we discuss emerging evidence on the application of O3I in sports and physical exercise, highlighting its promising role as a biomarker in a wide range of sports practices.

Biological assessment of the omega-3 status after omega-3 enriched dietary during an active seasonal performance on soccer players

BACKGROUND

To assess the physiological change of blood fatty acid composite during the seasonal performance of soccer players with omega-6/omega-3 polyunsaturated fatty acid balanced dietary supplementation.

METHODS

This study included 20 healthy and trained male soccer players. During the study, data collection was performed three times (pre-, mid-, post-season). Anthropometric data collection and blood sampling for the assessment of the omega index were performed. The mid- and post-seasonal data were compared with baseline data collected before the starting season (pre-seasonal data).

RESULTS

Elevated levels of omega-3, HS-omega, and trans fatty acid were observed in both the mid- and post-seasonal data. During the season, the levels of omega-6/omega-3 and saturated fatty acid decreased, whereas there were no differences in total cholesterol, cholesterol LDL, HDL, BUN/Cr, HbA1c (NGSP), and cystatin C.

CONCLUSIONS

n-3 PUFA-enriched dietary supplementation might alter blood omega-3 indices in soccer players during the season.

Effect of Dietary Supplementation with Omega-3 Fatty Acid on the Generation of Regulatory T Lymphocytes and on Antioxidant Parameters and Markers of Oxidative Stress in the Liver Tissue of IL-10 Knockout Mice

INTRODUCTION

chronic low-grade inflammation, or inflammaging, emerges as a crucial element in the aging process and is associated with cardiovascular and neurological diseases, sarcopenia, and malnutrition. Evidence suggests that omega-3 fatty acids present a potential therapeutic agent in the prevention and treatment of inflammatory diseases, mitigating oxidative stress, and improving muscle mass, attributes that are particularly relevant in the context of aging. The objective of the present study was to evaluate the effectiveness of supplementation with omega-3 fish oil in improving the immune response and oxidative stress in knockout mice for interleukin IL-10 (IL-10-/-).

MATERIAL AND METHODS

female C57BL/6 wild-type (WT) and interleukin IL-10 knockout (IL-10-/-) mice were fed during 90 days with a standard diet (control groups), or they were fed/supplemented with 10% of the omega-3 polyunsaturated fatty acid diet (omega-3 groups). Muscle, liver, intestinal, and mesenteric lymph node tissue were collected for analysis.

RESULTS

the IL-10-/-+O3 group showed greater weight gain compared to the WT+O3 (p = 0.001) group. The IL-10-/-+O3 group exhibited a higher frequency of regulatory T cells than the IL-10-/- group (p = 0.001). It was found that animals in the IL-10-/-+O3 group had lower levels of steatosis when compared to the IL-10-/- group (p = 0.017). There was even greater vitamin E activity in the WT group compared to the IL-10-/-+O3 group (p = 0.001) and WT+O3 compared to IL-10-/-+O3 (p = 0.002), and when analyzing the marker of oxidative stress, MDA, an increase in lipid peroxidation was found in the IL-10-/-+O3 group when compared to the IL-10-/- group (p = 0.03). Muscle tissue histology showed decreased muscle fibers in the IL-10-/-+O3, IL-10-/-, and WT+O3 groups.

CONCLUSION

the findings show a decrease in inflammation, an increase in oxidative stress markers, and a decrease in antioxidant markers in the IL-10-/-+O3 group, suggesting that supplementation with omega-3 fish oil might be a potential intervention for inflammaging that characterizes the aging process and age-related diseases.

Competitive season effects on polyunsaturated fatty acid content in erythrocyte membranes of female football players

BACKGROUND

An optimal and correctly balanced metabolic status is essential to improve sports performance in athletes. Recent advances in omic tools, such as the lipid profile of the mature erythrocyte membranes (LPMEM), allow to have a comprehensive vision of the nutritional and metabolic status of these individuals to provide personalized recommendations for nutrients, specifically, the essential omega-3 and omega-6 fatty acids, individuating deficiencies/unbalances that can arise from both habitual diet and sportive activity. This work aimed to study the LPMEM in professional female football players during the football season for the first time and compare it with those defined as optimal values for the general population and a control group.

METHODS

An observational study was carried out on female football players from the Athletic Club (Bilbao) playing in the first division of the Spanish league. Blood samples were collected at three points: at the beginning, mid-season, and end of the season for three consecutive seasons (2019-2020, 2020-2021, and 2021-2022), providing a total of 160 samples from 40 women. The LPMEM analysis was obtained by GC-FID by published method and correlated to other individual data, such as blood biochemical parameters, body composition, and age.

RESULTS

We observed a significant increase in docosahexaenoic acid (DHA) (p 0.048) and total polyunsaturated fatty acid (PUFA) (p 0.021) in the first season. In the second season, we observed a buildup in the membrane arachidonic acid (AA) (p < .001) and PUFA (p < .001) contents when high training accumulated. In comparison with the benchmark of average population values, 69% of the football players showed lower levels of omega-6 dihomo-γ-linolenic acid (DGLA), whereas 88%, 44%, and 81% of the participants showed increased values of AA, eicosapentaenoic acid (EPA), and the ratio of saturated and monounsaturated fatty acids (SFA/MUFA), respectively. Regarding relationships between blood biochemical parameters, body composition, and age with LPMEM, we observed some mild negative correlations, such as AA and SFA/MUFA ratio with vitamin D levels (coefficient = -0.34 p = .0019 and coefficient = -.25 p = .042); DGLA with urea and cortisol (coefficient = -0.27 p < .006 and coefficient = .28 p < .0028) and AA with age (coefficient = -0.33 p < .001).

CONCLUSION

In conclusion, relevant variations in several fatty acids of the membrane fatty acid profile of elite female football players were observed during the competitive season and, in comparison with the general population, increased PUFA contents were confirmed, as reported in other sportive activities, together with the new aspect of DGLA diminution, an omega-6 involved in immune and anti-inflammatory responses. Our results highlight membrane lipidomics as a tool to ascertain the molecular profile of elite female football players with a potential application for future personalized nutritional strategies (diet and supplementation) to address unbalances created during the competitive season.

The Effects of Omega-3 Fatty Acid Supplementation on the Lipid Profile and Cardiovascular Markers Following Downhill Running in Long-Distance Runners

Exercise-induced injury may intensify inflammatory response and reduce the cardiovascular protection mechanisms of omega 3 polyunsaturated fatty acids (ω 3 PUFA). Therefore, this study aimed to determine the erythrocyte content of fatty acids (ω 3 and ω 6), the levels of cardiac damage markers (CKMB, hsTnT, H - FABP), the concentration of inflammation mediators (IL-6, TNF α) in long distance runners supplemented with ω 3 PUFA. Twenty-four male long distance runners, who were randomly assigned to a placebo group (GrP) or a group supplemented (GrSuppl) with a daily dose of 3,000 mg of ω 3 PUFA for three weeks, participated in the study. Participants performed a downhill running exercise test. Blood samples were collected at rest and after the exercise protocol to analyse the levels of cardiac markers and inflammatory cytokines. The erythrocyte membrane content of EPA and DHA in the GrSuppl at the 3rd week of supplementation was significantly higher than at the baseline (p < 0.001). The erythrocyte membrane content of ω 3 PUFA in the GrSuppl was significantly higher at the completion of supplementation (p < 0.001). Supplementation with ω 3 PUFA improved blood lipid profiles and reduced the concentration of inflammation mediators measured after the eccentric exercise tests. The increased ω 3 PUFA content in the erythrocyte membrane and lower blood concentrations of cardiac damage markers and inflammation mediators in distance runners supplemented for three weeks with ω 3 PUFA suggest that the cardiovascular function has been improved.

Dietary Intake, Biological Status, and Barriers towards Omega-3 Intake in Elite Level (Tier 4), Female Athletes: Pilot Study

Omega-3 polyunsaturated fatty acids (n-3 PUFA) have unique properties which benefit athlete populations. The literature investigating NCAA collegiate, rugby sevens and German endurance athletes indicates suboptimal n-3 PUFA dietary intake and biological status. The aims of this study were: (i) to explore the dietary intakes and FA profiles of elite level, team-based, female athletes and (ii) to understand perceived barriers towards achieving n-3 dietary guidelines. A total of 35 athletes (24.8 ± 4.5 years) completed both a questionnaire and a finger prick test. All the participants reported consuming fish and seafood over the previous six months however only nine athletes consumed ≥ 2 servings of fish per week. Four participants reported using an n-3 supplement. The mean omega-3 index (O3I; including supplementers) was below target levels of >8% (5.19 ± 0.86%). O3I was significantly higher (p < 0.001) in those consuming ≥ 2 servings of fish per week and/or supplements (5.91 ± 0.81%) compared with those who did not (4.82 ± 0.63%). The main barriers reported by those not consuming two servings of fish per week were sensory (n = 11; 42%), cooking skills (n = 10; 38%) and knowledge of n-3 benefits (n = 7; 27%). The current study shows that elite level female athletes present with suboptimal n-3 dietary intake and O3I due to their food preferences, cooking skills and n-3 knowledge.

Omega-3 index and AA/EPA ratio as biomarkers of running-related injuries: An observational study in recreational runners

ABSTRACTThe aim of this study was to examine the association between biomarkers of polyunsaturated fatty acids (PUFA), such as omega-3 (ω-3) index and arachidonic acid (AA; 20:4 ω-6)/eicosapentaenoic acid (EPA; 20:5ω-3) ratio (AA/EPA), and the prevalence of running-related injuries (RRI) in a cohort of recreational runners. We performed a retrospective, observational study of 275 non-elite runners (mean age: 41.20 ± 12.47 years) who were not supplemented with ω-3 fatty acids. The training characteristics and RRI were recorded over a period of 12 months through a self-reported questionnaire. Using whole blood samples collected by finger prick, PUFA were quantified by gas chromatography and ω-3 index and AA/EPA ratio measured. A total of 191 RRI cases were reported, with an injury prevalence rate of 50.9% in the overall population. The injured runners ran a significantly greater weekly distance than uninjured subjects (53.54 ± 25.27 km/week; p = 0.007). In a multivariate regression analysis, the lowest number of RRI was associated with higher values of ω-3 index (β = - 0.237; 95% CI - 0.308 to - 0.164; R² = 0.172; p < 0.0001), while a higher AA/EPA ratio was correlated with higher number of RRI (β = 0.019; 95% CI 0.007-0.031; R² = 0.038; p = 0.003). This study identifies ω-3 index and AA/EPA ratio as potential parameters associated with the risk of RRI. Future research is needed to confirm these results and apply specific nutritional strategies to successfully modify these biochemical variables.Trial registration: ISRCTN.org identifier: ISRCTN12847156..

Optimization of Omega-3 Index Levels in Athletes at the US Naval Academy: Personalized Omega-3 Fatty Acid Dosage and Molecular Genetic Approaches

The Dietary Guidelines for Americans recommend increasing the intake of omega-3 polyunsaturated fatty acids. The Omega-3 Index (O3I) is one marker used to assess omega-3 status. The O3I national average is 4.3%, which translates into a high risk for developing cardiovascular disease. Research has reported an association between variants in the two desaturase encoding genes, fatty acid desaturase 1 and fatty acid desaturase 2 (FADS1/2), and the concentration of O3I. The aim of this study was to assess whether a personalized dosage of omega-3 supplementation would lead to an O3I ≥ 8%. A secondary aim was to identify if changes in O3I levels would be associated with either of the two FADS1/2 variants. Methods: This interventional study had a pre- and post-intervention design to assess changes in O3I. Ninety participants completed demographic, biometrics, O3I, and genetic testing. Participants were provided a personalized dose of omega-3 supplements based on their baseline O3I. Results: The majority (63%) of participants were 20 year old white males with an average O3I at baseline of 4.6%; the post-supplementation average O3I was 5.6%. The most frequent genetic variants expressed in the full sample for FADS1/2 were GG (50%) and CA/AA (57%). Conclusions: O3I was significantly increased following omega-3 supplementation. However, it was not possible to conclude whether the two FADS1/2 variants led to differential increases in OI3 or if a personalized dosage of omega-3 supplementation led to an O3I ≥ 8%, due to our study limitations.

Whole blood long-chain n-3 fatty acids as a measure of fish oil compliance in children with acute lymphoblastic leukemia: a pilot study

Long-chain n-3 fatty acids (n-3 LCPUFA) may prevent chemotherapy-induced hyperlipidemia in children with acute lymphoblastic leukemia (ALL). However, compliance could be a problem and intake-biomarker correlations may be affected by bodyweight and blood transfusions. We assessed whole blood n-3 LCPUFA three times during the first 83 days of treatment in six 1-17-year-old children with ALL, who received 2.4-4.9 g/d n-3 LCPUFA depending on bodyweight. Mean compliance was 73%, which resulted in a 2.5-fold increase in blood n-3 LCPUFA irrespective of blood transfusions. The correlation between relative blood content of n-3 LCPUFA and intake in g/d across the study period was strong (r=0.76, p=0.001). When n-3 LCPUFA was expressed in absolute concentrations and intake per kg bodyweight the correlation decreased (r=0.39, p=0.164) and was driven by baseline values. Thus, relative content of n-3 LCPUFA in blood reflects fish oil compliance in children with ALL despite blood transfusions and differences in bodyweight.

Krill-Oil-Dependent Increases in HS-Omega-3 Index, Plasma Choline and Antioxidant Capacity in Well-Conditioned Power Training Athletes

There is evidence that both omega-3 polyunsaturated fatty acids (n-3 PUFAs) and choline can influence sports performance, but information establishing their combined effects when given in the form of krill oil during power training protocols is missing. The purpose of this study was therefore to characterize n-3 PUFA and choline profiles after a one-hour period of high-intensity physical workout after 12 weeks of supplementation. Thirty-five healthy power training athletes received either 2.5 g/day of Neptune krill oil^TM (550 mg EPA/DHA and 150 mg choline) or olive oil (placebo) in a randomized double-blind design. After 12 weeks, only the krill oil group showed a significant HS-Omega-3 Index increase from 4.82 to 6.77% and a reduction in the ARA/EPA ratio (from 50.72 to 13.61%) (p < 0.001). The krill oil group showed significantly higher recovery of choline concentrations relative to the placebo group from the end of the first to the beginning of the second exercise test (p = 0.04) and an 8% decrease in total antioxidant capacity post-exercise versus 21% in the placebo group (p = 0.35). In conclusion, krill oil can be used as a nutritional strategy for increasing the HS-Omega-3 Index, recover choline concentrations and address oxidative stress after intense power trainings.

The Effect of Omega-3 Fatty Acid Supplementation on Serum Adipocytokines, Lipid Profile and Biochemical Markers of Inflammation in Recreational Runners

BACKGROUND

The study aimed to evaluate the effects of a 3-week ω-3 PUFA supplementation on serum adipocytokines (i.e., adiponectin, leptin), neuregulin-4 (NRG4) and erythrocyte omega-3 (ω-3) fatty acid content, as well as the blood antioxidant defense capacity in non-elite endurance runners.

METHODS

Twenty-four runners were randomized into two groups: the supplemented group, who received omega free fatty acids extract containing 142 mg of EPA, 267 mg of DHA, 12 mg of vitamin E and 5 µg of vitamin D, each administrated at a dose of six capsules twice a day for three weeks, or the placebo group. Venous blood samples were withdrawn at the start and at the end of the study protocols to estimate serum biochemical variables.

RESULTS

A significantly higher ω-3 index and lower AA/EPA ratio was observed after ω-3 PUFA compared to pre-supplementation levels (p < 0.001 and p < 0.001, respectively). An increase in baseline adiponectin and NRG4 levels, as well as a decrease of leptin concentration and lipid profile improvement, were observed in subjects after a ω-3 PUFA diet. The increased ω-3 index had a significant effect on TNFα levels and a serum marker of antioxidant defense.

CONCLUSIONS

The ω-3 PUFA extract with added vitamin E and D supplementation may have a positive effect on the function of the adipocyte tissue, as well as the ability to prevent cardiovascular complications in athletes.

Are There Benefits from the Use of Fish Oil Supplements in Athletes? A Systematic Review

Despite almost 25 y of fish oil supplementation (FS) research in athletes and widespread use by the athletic community, no systematic reviews of FS in athletes have been conducted. The objectives of this systematic review are to: 1) provide a summary of the effect of FS on the athlete's physiology, health, and performance; 2) report on the quality of the evidence; 3) document any side effects as reported in the athlete research; 4) discuss any risks associated with FS use; and 5) provide guidance for FS use and highlight gaps for future research. Electronic databases (PubMed, Embase, Web of Science, Google Scholar) were searched up until April 2019. Only randomized placebo-controlled trials (RCTs) in athletes, assessing the effect of FS on a health, physiological/biochemical, or performance variable were included. Of the 137 papers identified through searches, 32 met inclusion criteria for final analysis. Athletes varied in classification from recreational to elite, and from Olympic to professional sports. Mean age for participants was 24.9 ± 4.5 y, with 70% of RCTs in males. We report consistent effects for FS on reaction time, mood, cardiovascular dynamics in cyclists, skeletal muscle recovery, the proinflammatory cytokine TNF-α, and postexercise NO responses. No clear effects on endurance performance, lung function, muscle force, or training adaptation were evident. Methodological quality, applying the Physiotherapy Evidence Database (PEDro) scale, ranged from 6 to a maximum of 11, with only 4 RCTs reporting effect sizes. Few negative outcomes were reported. We report various effects for FS on the athlete's physiology; the most consistent findings were on the central nervous system, cardiovascular system, proinflammatory cytokines, and skeletal muscle. We provide recommendations for future research and discuss the potential risks with FS use.

Dietary and Biological Assessment of the Omega-3 Status of Collegiate Athletes: A Cross-Sectional Analysis

Omega-3 fatty acids (ω-3 FA) are associated with cardiovascular health, brain function, reduction of inflammation, and several other physiological roles of importance to competitive athletes. The ω-3 FA status of National Collegiate Athletic Association (NCAA) Division I athletes has not been well-described. The purpose of this study was to evaluate the ω-3 FA status of NCAA Division I athletes using dietary and biological assessment methodology. Athletes from nine NCAA Division I institutions from throughout the U.S. (n = 1,528, 51% male, 34 sports represented, 19.9 ± 1.4 years of age) completed a food frequency questionnaire (FFQ) to assess ω-3 FA from diet and supplements. Omega-3 Index (O3i) was evaluated in a sub-set of these participants (n = 298, 55% male, 21 sports represented, 20.0 ± 1.3 years of age) using dried blood spot sampling. Only 6% (n = 93) of athletes achieved the Academy of Nutrition & Dietetics’ recommendation to consume 500 mg DHA+EPA per day. Use of ω-3 FA supplements was reported by 15% (n = 229) of participants. O3i was 4.33 ± 0.81%, with no participants meeting the O3i benchmark of 8% associated with the lowest risk of cardiovascular disease. Every additional weekly serving of fish or seafood was associated with an absolute O3i increase of 0.27%. Overall, sub-optimal ω-3 FA status was observed among a large, geographically diverse group of male and female NCAA Division I athletes. These findings may inform interventions aimed at improving ω-3 FA status of collegiate athletes. Further research on athlete-specific ω-3 FA requirements is needed.

Blood Biomarker Profiling and Monitoring for High-Performance Physiology and Nutrition: Current Perspectives, Limitations and Recommendations

Blood test data were traditionally confined to the clinic for diagnostic purposes, but are now becoming more routinely used in many professional and elite high-performance settings as a physiological profiling and monitoring tool. A wealth of information based on robust research evidence can be gleaned from blood tests, including: the identification of iron, vitamin or energy deficiency; the identification of oxidative stress and inflammation; and the status of red blood cell populations. Serial blood test data can be used to monitor athletes and make inferences about the efficacy of training interventions, nutritional strategies or indeed the capacity to tolerate training load. Via a profiling and monitoring approach, blood biomarker measurement combined with contextual data has the potential to help athletes avoid injury and illness via adjustments to diet, training load and recovery strategies. Since wide inter-individual variability exists in many biomarkers, clinical population-based reference data can be of limited value in athletes, and statistical methods for longitudinal data are required to identify meaningful changes within an athlete. Data quality is often compromised by poor pre-analytic controls in sport settings. The biotechnology industry is rapidly evolving, providing new technologies and methods, some of which may be well suited to athlete applications in the future. This review provides current perspectives, limitations and recommendations for sports science and sports medicine practitioners using blood profiling and monitoring for nutrition and performance purposes.

Cross-sectional study of the combined associations of dietary and supplemental eicosapentaenoic acid + docosahexaenoic acid on Omega-3 Index

Studies have linked an Omega-3 Index (O3I), which measures eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) in red blood cell membranes, of ≥8% with improved health. Previous studies found that the American Heart Association (AHA) recommendation of 1-2 seafood meals per week does not achieve an O3I ≥8% even with an EPA + DHA supplement; however, these studies did not assess the frequency or amount of supplemental intake. Among participants in a predominantly US and Canadian cohort with high nutrient supplement use, we hypothesized that those adhering to the AHA guidelines would not have an average O3I ≥8% but that those taking a daily supplement would. Fish consumption and EPA + DHA supplement use were reported by 1795 participants; 985 also completed a blood spot test for O3I. A majority (71%) consumed <2 servings per week of fatty fish, and 61% took an EPA + DHA supplement. The amount of EPA + DHA for 1 serving (based on the product label) significantly differed among the >400 supplement products (50-3570 mg). O3I was ≥8.0% in 19% of participants. Among non-supplement takers, 3% of those consuming 1 fish serving per week and 17% consuming ≥2 achieved an O3I ≥8.0%. Among those consuming ≥2 fish servings per week, only those also taking an average of 1100 mg/d of supplemental EPA + DHA had a median O3I ≥8.0%. Based on the relationship between supplemental EPA + DHA intake and O3I for non-fish eaters (R² = 0.40, P < .0001), an average of ~1300 mg/d of EPA + DHA achieved an O3I of 8.0%. This study suggests that following the AHA guidelines does not produce an O3I ≥8% nor does taking 1 serving per day of most omega-3 supplements.