Study: Fish Oil Doesn't Affect Postpartum Depression
Nor Does Fish Oil Boost Children's Learning
DHA and Effects: Industry Speaks
The study findings are inconsistent with those of many previous studies, says Duffy MacKay, ND, vice-president of scientific and regulatory affairs for the Council for Responsible Nutrition in Washington, D.C., a trade association representing manufacturers and ingredient suppliers of dietary supplements.
He also sees some weaknesses in the study. "The timeliness of the intervention may be off," he says, explaining that starting the supplements earlier than 21 weeks may have been better.
Some researchers question whether the most valuable nutrient for depression is DHA or another fatty acid, EPA. So knowing the levels of both EPA and DHA in mothers and infants would have been good information, he says.
Makrides' plan to assess the children later is a good one, he says.
His advice on DHA and EPA? "Make sure you get these nutrients, whether getting them from food or supplements."
DHA During Pregnancy: Conclusions
''This is the largest and most well conducted study of its type," Makrides says, "so we have a conclusive result about the fact that there is little or no effect of DHA supplementation during normal pregnancy on postpartum depression or early childhood neurodevelopment."
She does concede that further work is needed to determine the benefits of DHA for women with a history of depression or those at risk of delivering prematurely.
DHA During Pregnancy: Second Opinion
The final word is not yet in, says Emily Oken, MD, MPH, associate professor of population medicine at Harvard Medical School in Boston, who co-authored an editorial to accompany the study. She writes that the topic requires more investigation, including additional trials such as the Australian one.
It could be that the Australian study did not include women most at risk of postpartum depression, she says.
Until more study is done, Oken says, she advises pregnant women to get the recommended 200 milligrams a day of DHA, preferably by eating fish low in mercury and high in DHA.
"Most women can get [the recommended amount] by eating one or two fish servings a week of fattier fish, such as salmon or herring," she says. "If they can't or won't, it's reasonable and safe to take a supplement."