In a recent review published in the journal Nutrients, researchers evaluated the evidence on the effects of two omega-3 polyunsaturated fatty acids (n-3 PUFAs), namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the health of athletes. They also discussed the risks and benefits associated with DHA and EPA supplementation in this population.
Study: Athletes Can Benefit from Increased Intake of EPA and DHA—Evaluating the Evidence. Image Credit: UfaBizPhoto / Shutterstock
Athletes should approach supplement use cautiously, prioritizing safety and efficacy evaluation. The Australian Institute of Sport (AIS) framework classifies dietary supplements, placing fish oil (EPA and DHA) in Category B. It indicates a supportive scientific background but emphasizes the need for further research to understand its benefits for athletes fully.
n-3PUFAs are essential for the human body but cannot be produced de novo. Plant sources like nuts and seeds provide a precursor named alpha-linolenic acid (ALA), but its conversion to EPA and DHA is limited. The omega-3 index (O3I), reflecting EPA and DHA levels, is considered optimal above 8%. Athletes, like the general population, often have a suboptimal O3I, emphasizing the potential benefits of EPA and DHA supplements for inflammation control, cognitive function, neuroprotection, muscle maintenance, and training adaptations. Therefore, researchers in the present review aimed to discuss the effects, pros, and cons of EPA and DHA supplementation in athletes.
Effects and underlying mechanisms
EPA and DHA have unique molecular structures and exert multifaceted effects on human physiology. Acting through various receptors and transcription factors, they modulate inflammation while influencing cell membrane structure and the production of bioactive oxylipins. Their conversion to specialized pro-resolving mediators (SPMs) plays a pivotal role in resolving inflammation, impacting immunity, tissue repair, and homeostasis. Additionally, these fatty acids form bioactive molecules like endocannabinoids, influencing appetite, inflammation, and cognition. DHA, constituting 10–20% of the human brain's lipid content, plays a vital role in nerve impulse transmission, neuroplasticity, membrane stability, and cell communication. Its neuro-supportive functions may provide benefits in sports-related traumatic brain injury, cognition, neuromuscular performance, training-induced muscle adaptations, and recovery from injury.
Therefore, inadequate levels of EPA and DHA may compromise inflammation resolution, affecting health conditions ranging from arthritis to aging-related disorders.
EPA and DHA are primarily present in oily fish, such as mackerel, salmon, and certain algae. However, the variability, taste preferences, and concerns about heavy metal contamination in these sources contribute to their insufficient consumption, impacting EPA and DHA intake. Despite these challenges, the health benefits of fish consumption appear to outweigh the associated risks.
Microalgae species like Schizochytrium spp., Crytthecodiniumcohnii, and Phaeodactylumtricornutum serve as plant sources for the production of EPA and DHA supplements. While current guidelines suggest an adequate intake of 250 mg/day for adults, studies propose that optimal EPA + DHA intake, necessary for an O3I ≥ 8%, may require doses higher than existing recommendations. Backing this notion, scoping reviews suggest 1000–1500 mg/day for 12 weeks or longer. Currently, the International Olympic Committee (IOC) suggests a daily dose of approximately 2 g of EPA + DHA for potential health and performance benefits in athletes.
Status and use of EPA and DHA in athletes
Studies conducted on professional and amateur athletes practicing football, basketball, and other winter sports show suboptimal O3I levels in them, indicating the need for potential EPA and DHA supplementation. There are several potential benefits of this supplementation. Studies indicate improved reaction time, cognitive performance, and reduced negative mood. In sports-related traumatic brain injury, DHA supplementation is shown to lower the biomarkers associated with head trauma. Moreover, during recovery from injury, EPA and DHA may attenuate muscle atrophy and enhance skeletal muscle volume and mass, demonstrating promising application in athletes undergoing recovery. Over a range of doses, supplementation consistently reduces muscle soreness after exercise-induced damage, with potential dose-dependent effects on power and strength recovery. Additionally, recent studies suggest that supplementation of DHA and EPA enhances resistance training adaptations and increases muscle strength without affecting lean body mass. Improvements in running economy and peak oxygen uptake have also been observed, indicating potential benefits for athletes in both resistance and endurance-based sports.
Potential adverse effects of supplementation
The adverse effects of EPA and DHA supplementation include gastrointestinal disturbances like fishy aftertaste, altered platelet function (increased bleeding risk), and concerns about lipid peroxidation. However, evidence suggests that these effects may be minimal or absent at standard doses, with several health authorities considering EPA and DHA supplementation safe at recommended doses for the general population.
The recommendations for athletes regarding EPA and DHA supplementation involve considerations of dose, timing, chemical formulation, and the relative concentration of these fatty acids. Optimal intake should align with specific athletic goals. Further, bioavailability may be enhanced when supplements are taken with meals. Both EPA and DHA offer similar qualitative benefits, and supplement selection should prioritize high content of EPA, DHA, or both.
In summary, considering the diverse benefits of EPA and DHA, their supplements at recommended doses appear reasonable for use in athletes without adverse effects. However, further research is essential to determine optimal doses, durations, and consistent effects relevant to athletes before categorizing them as sports supplements above AIS category B.