DHAs

DHAs, or docosahexaenoic acids, are a group of long-chain omega-3 fatty acids characterized by a 22-carbon chain with six cis double bonds (22:6(n-3)). They are essential components of cell membranes in the brain and retina and occur predominantly in marine sources and some microalgae. The term DHAs refers to docosahexaenoic acids in the plural.

Dietary DHA comes mainly from fatty fish such as salmon, mackerel, and sardines, and from algae-based supplements. Some DHA is synthesized in the body from alpha-linolenic acid, but the conversion efficiency is low in humans; vegetarians and vegans often rely on algae-derived DHA. Fortified foods also provide DHA.

In membranes, DHA influences fluidity and function of neural and retinal cells and participates in signaling pathways and inflammatory regulation. It is especially important during fetal and early postnatal development for brain and visual cortex maturation; DHA levels in infancy relate to cognitive and visual outcomes.

Evidence supports DHA's role in prenatal development and potentially in cardiovascular health, though results are mixed for other outcomes. Most guidelines recommend a daily intake of EPA+DHA or DHA for adults, and higher intake for pregnant or lactating individuals. The optimal dose varies by country and organization.

Common safety considerations include contamination in fish products and oxidation in supplements. Sourcing from reputable, tested products is advised. DHA can also be obtained from algal sources for those avoiding animal products; excessive intake is uncommon but may interact with bleeding risk at very high doses.