What is DHA? It's also commonly known as Docosahexaenoic acid which is an omega-3 essential fatty acid. In chemical structures, it composes of carboxylic acid with a 22-carbon chain and six cis (cis-trans isomerism) double bonds. Docosahexaenoic acid is most often found in fish oil which is originates on various photosynthetic and heterotrophic microalgae, and concentrates in organisms as it moves up the food chain.

Docosahexaenoic acid (DHA) may regulate stress mediators, such as catecholamine's (high levels in the blood are associated with stress) and pro-inflammatory cytokines (intercellular messengers responsible for signaling many cellular functions), and it may help reduce perceived stress, according to a study reported in Nutrition Journal.

Members of a university staff who were stressed (measured by a score of 17 on the Perceived Stress Scale) were randomized to two groups for a six-week trial. Group one took six grams of fish oil containing 1.5 grams per day of DHA. Group two took a placebo (six grams of olive oil). The groups were compared to one another and also to a wider cross-sectional study population that did not receive any treatment.

The subjects had significant reductions in perceived stress in both the treatment and placebo groups from baseline to the study's conclusions. However, the fish-oil group had a significantly better rate of stress reduction compared to the control group while the placebo group did not. The researchers stated that DHA appeared to have adaptogenic effects but that a larger study was needed to support the findings.