Fish oil supplements do not boost babies’ cognitive development or prevent postpartum depression

The New York Times reports, “Many women take fish oil supplements during pregnancy, encouraged by obstetricians, marketing campaigns, or the popular view that a key fish oil ingredient — docosahexaenoic acid, or DHA — is beneficial to a baby’s cognitive development.” However, a study published “in the Journal of the American Medical Association suggests that the DHA supplements taken by pregnant women show no clear cognitive benefit to their babies.” What’s more, researchers “found no evidence that DHA can reduce postpartum depression, except perhaps for women already at high risk for it.”

“In the new study, 2,399 women at the midpoint of their pregnancies were divided into two groups,” the Los Angeles Times reports. “One took a daily capsule of 800 mg of DHA derived from fish oil until giving birth; the other took an identical capsule filled with vegetable oil.”

Then, “six weeks and six months after each woman delivered her baby, researchers had her complete a psychological inventory to check for symptoms of depression.” Next, when the babies were about 18 months old, investigators subjected them to comprehensive batteries of tests to measure their cognitive ability.

The Wall Street Journal reports that the study authors found no evidence that the fish oil supplements prevented new mothers from postpartum depression or enhanced cognitive development in their babies. However, the study indicated that 800 mg of fish oil daily appeared to decrease the chances of developing postpartum depression by about four percent in women who already had a history of clinical depression. This was not considered a statistically significant difference, however.

According to a report in Bloomberg News, an editorial accompanying the study “said pregnant women shouldn’t give up eating low-mercury fish or taking recommended doses of fish oil, as the mineral does help prevent preterm labor and may have benefits not shown in the study.”

“The study did find that significantly fewer infants from the DHA group spent time in the neonatal intensive care unit, compared to infants in the control group — something that researchers attributed to fewer preterm births in the DHA group,” HealthDay reported. “DHA supplementation was associated with a ‘small to modest increase in the duration of gestation,’ they reported.”

WebMD reported that, despite the study’s conclusions, the authors “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,” a concession echoed by the authors of the accompanying editorial.

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