Omega-3 fatty acids consumed during pregnancy may reduce the risk of postpartum depression, but a larger study is needed, U.S. researchers say. In a randomized, double-blind, placebo-controlled dietary intervention trial, 52 pregnant women took either a placebo, corn oil, or a fish oil capsule containing 300 milligrams of DHA five days each week from 24-40 weeks of pregnancy -- the same amount a woman would consume if she ate about one-half serving of salmon.

Dr. Michelle Price Judge of the University of Connecticut School of Nursing says dietary DHA intake during pregnancy has been estimated to be 50 to 70 milligrams of DHA daily -- a fraction of the 200 milligrams daily that is considered optimal during pregnancy by most experts.

Judge and colleagues concluded DHA consumed during pregnancy -- at levels that are reasonably attained from food -- has the potential to decrease symptoms of postpartum depression.

The study did not have enough women to investigate whether fish oil consumption resulted in a lower incidence of diagnosable postpartum depression, but the women in the treatment group who consumed the fish oil had significantly lower total Postpartum Depression Screening Scale scores, with significantly fewer symptoms.

Although larger-scale intervention studies will be needed to better understand how fish oil consumption can improve postpartum mental health, women would be wise to eat at least a serving of high-omega-3 fish two to three days per week, Judge says. The findings were presented the Experimental Biology meeting in Washington.