omega3

Omega-3 fatty acids are a group of polyunsaturated fats that are important for normal cellular function and development. The trio most discussed for human health consists of alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). ALA is an an essential fatty acid, meaning the body cannot synthesize it and must obtain it from the diet. EPA and DHA are primarily obtained from marine sources and can be formed in small amounts from ALA in the body, though the conversion is limited.

Dietary sources include fatty fish and fish oil for EPA and DHA, and plant oils such as flaxseed, chia seeds, walnuts, and canola oil for ALA. Algal oil provides a vegetarian source of EPA and DHA. ALA can be converted to EPA and DHA to some extent, but this process is inefficient in humans.

Omega-3s are components of cell membranes and influence membrane fluidity and cell signaling. DHA is especially enriched in the brain and retina. EPA and DHA have anti-inflammatory properties and can modestly affect triglyceride levels and, to a lesser extent, blood pressure and heart rhythm.

Evidence for health benefits varies by outcome. Substantial evidence supports cardiovascular benefits with EPA and DHA, particularly for triglyceride reduction and in people with elevated risk. Benefits for cognitive function in healthy adults are less clear, while adequate DHA intake is important for fetal and infant development. Potential risks include bleeding at high doses and contamination in some fish products; supplements should be used with caution by those on anticoagulants.

General advice often cites about 250–500 mg per day of EPA+DHA for healthy adults, with higher amounts for certain conditions, and at least two servings of fatty fish weekly as a practical goal.