The Omega-3 Index and Self-Reported Dietary Intake of DHA and EPA in Highly Trained, Elite and World Class (Tier 3–5) Male and Female Athletes: An Australian Based Cross-sectional Study

BACKGROUND: Long-chain omega-3 fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) support cardiovascular health; however, athletes often exhibit Omega-3 Index (O3I) levels below 8%, a threshold associated with reduced cardiovascular disease (CVD) risk, suggesting insufficient dietary intake of DHA and EPA. Therefore, the objective of this study was to characterise the O3I, dietary intake of DHA and EPA, and supplement use in a large cohort of highly trained, elite and world class (Tier 3-5) Australian based athletes. METHODS: In this multi-site cross-sectional study, 595 male and female athletes (18-45 years) from 17 sports provided a dried blood spot for whole blood fatty acid analysis and completed a dietary survey. The O3I was derived using a validated conversion algorithm. Dietary DHA and EPA intake was assessed using a marine food frequency questionnaire. Group comparisons were conducted using Mann-Whitney U and independent-samples t-tests, and differences across intake quartiles were assessed using Kruskal-Wallis tests. RESULTS: Mean (SD) O3I was 5.88 ± 1.40%, with 3% of athletes < 4%, 60% between 4-6%, 30% between 6-8%, and only 7% ≥ 8%. O3I increased across DHA + EPA intake quartiles (p < 0.001) and was higher in males than females (p < 0.01). Athletes reporting omega-3 supplement use (19%) had higher O3I (Median [IQR]) compared with non-users (7.02 [6.28-8.01%] vs 5.38 [4.82-6.02%]; p < 0.001). Median total daily DHA + EPA intake was 261 mg/day, with 72% of athletes consuming < 500 mg/day. Daily whole-food intake of DHA + EPA was modest and did not differ by sex. CONCLUSION: Most athletes based in Australia had O3I below the ≥ 8% CVD risk reduction threshold, highlighting opportunities for organisations and sporting bodies to support initiatives that increase DHA and EPA intake.