Docosahexaenoic acid

Docosahexaenoic acid (DHA) is an omega-3 fatty acid with 22 carbon atoms and six double bonds. It is abundant in marine oils and a major structural lipid in the brain and retina.

Fatty acid: A carboxylic acid with a hydrocarbon chain, serving as a building block of many lipids. DHA is a long-chain fatty acid whose carbon chain carries six double bonds.
Alpha-linolenic acid: An essential omega-3 fatty acid with 18 carbon atoms and three double bonds. Humans can convert this dietary precursor into DHA, though conversion is limited.
Retina: The light-sensitive neural tissue lining the back of the eye. DHA is highly concentrated in retinal photoreceptor membranes.
Eicosapentaenoic acid: An omega-3 fatty acid with 20 carbon atoms and five double bonds, commonly abbreviated EPA. EPA is the other prominent long-chain omega-3 in fish oil, with a shorter chain and distinct roles.
Polyunsaturated fatty acid: A fatty acid containing two or more carbon–carbon double bonds. DHA belongs to this class because its chain contains six double bonds.
Fatty acid synthesis: A set of biochemical pathways that build fatty acids from acetyl-CoA and related precursors. DHA production uses elongation and desaturation steps beyond ordinary fatty-acid synthesis.
Photoreceptor cell: A retinal cell that converts light into electrical signals. DHA-rich membranes support the structure and function of these light-sensing cells.
Docosapentaenoic acid: An omega-3 fatty acid with 22 carbon atoms and five double bonds, abbreviated DPA. DPA has the same chain length as DHA but one fewer double bond.
Omega-3 fatty acid: A polyunsaturated fatty acid whose first double bond is three carbons from the methyl end. DHA’s omega-3 position distinguishes it from omega-6 fatty acids.
Elongation of very long-chain fatty acids protein 2: An enzyme that elongates long-chain fatty acids, including intermediates in DHA synthesis. ELOVL2 catalyzes key chain-lengthening steps on the route from alpha-linolenic acid to DHA.

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Infant formulaRelated: Some formulas include it as a long-chain fatty acid associated with neural and visual development.