Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are essential omega-3 fatty acids. The body cannot produce them efficiently, making dietary intake necessary. They play significant roles in maintaining overall health.
Understanding EPA and DHA
EPA and DHA are classified as long-chain polyunsaturated fatty acids (PUFAs), distinct from alpha-linolenic acid (ALA), another omega-3 found in plants like flaxseed and walnuts. While ALA can convert into EPA and then DHA, this conversion is often inefficient, with less than 15% of ALA typically transforming into EPA and even less into DHA. Directly consuming EPA and DHA is a more effective way to increase their levels.
These fatty acids integrate into cell membranes, influencing fluidity and cell signaling. This structural role allows cells to communicate effectively and maintain integrity. Their presence helps regulate various cellular processes, contributing to diverse health benefits.
Brain and Eye Development
DHA plays a significant role in brain and eye development and health. It is a major structural component of the brain, making up about 60% of its fat content, predominantly in gray matter, involved in sensory perception and intelligence. Its rapid accumulation occurs during the last trimester of pregnancy and continues through the first two years of life, making DHA crucial for neural development, supporting nerve cell growth and myelin sheath insulation.
For infants, adequate DHA intake is associated with improved visual acuity, enhanced learning, and better cognitive, social, emotional, and behavioral development. Studies link higher maternal DHA levels during pregnancy to advanced attention spans in infants and improved hand-eye coordination in children. In adults, DHA contributes to maintaining normal brain function, supporting memory, and potentially mitigating age-related cognitive decline.
The retina contains a high concentration of DHA (up to 65%), enhancing photoreceptor development and maintaining visual acuity and retinal health. EPA also contributes to eye health by reducing inflammation and oxidative stress.
Cardiovascular and Inflammatory Support
EPA and DHA contribute to cardiovascular health and modulate inflammatory responses. They help maintain healthy blood pressure and reduce triglyceride levels, which are fats in the blood that can contribute to heart disease. Research indicates that consuming EPA and DHA can lower the risk of coronary heart disease.
These omega-3 fatty acids exert their anti-inflammatory effects through multiple mechanisms. They become incorporated into cell membranes, altering fatty acid composition and influencing signaling molecule production. EPA and DHA give rise to specialized pro-resolving mediators (e.g., resolvins, protectins, maresins), which actively help resolve inflammation. They also inhibit pro-inflammatory transcription factors, reducing inflammatory gene expression and cytokine production.
While both EPA and DHA are anti-inflammatory, DHA shows a broader effect in attenuating pro-inflammatory cytokines, while EPA is effective in improving the balance between pro- and anti-inflammatory proteins.
Sources and Recommended Intake
Sufficient EPA and DHA are primarily obtained through diet and supplementation. Fatty fish (salmon, mackerel, tuna, herring, sardines) are rich sources of these omega-3s. These fish acquire EPA and DHA from microalgae. Algae oil, derived directly from microalgae, is a vegetarian and vegan-friendly source of both DHA and, in some formulations, EPA.
For healthy adults, many health organizations recommend a combined daily intake of 250–500 mg of EPA and DHA. During pregnancy and lactation, the need for omega-3 fatty acids increases, with recommendations often including an additional 200–300 mg of DHA per day to support fetal development. The Dietary Guidelines for Americans suggest consuming 8-12 ounces of seafood per week, typically providing approximately 250 mg of EPA and DHA daily.
When considering supplements, check for purity and dosage to ensure adequate EPA and DHA intake.