Docosahexaenoic acid (commonly known as DHA; 22:6 omega-3) is an omega-3 fatty acid. It is most often found in fish oil.
DHA can reduce the level of blood triglycerides in humans, which may reduce the risk of heart disease. Low levels of DHA have been associated with ADHD, Alzheimer's disease, and depression, among other diseases, although at present there is little evidence that DHA supplementation is effective in combating such diseases.
DHA in infant formula and breast milk
DHA has been an ingredient in several brands of premium infant formula sold in North America since 2001, after approval by the Food and Drug Administration and Health Canada. It, together with arachidonic acid (ARA), are permitted in infant formula because both are components of breast milk found around the world. DHA concentrations in breast milk range from 0.07% to greater than 1.0% of total fatty acids, with a mean of about 0.34%. DHA levels in breast milk are higher if a mother's diet is high in fish.
DHA makes infant formula more like human milk than "conventional" formula containing linolenic acid and linoleic acid, which are precursors. Formula sold in North America uses lipids from microorganisms grown in bioreactors as sources of DHA.