Wednesday, October 20, 2010
Babies No Smarter From Fish Oil Pills
This new study, published this week in the prestigious Journal of the American Medical Association (JAMA) by researchers of the University of Adelaide in Australia, reports on the results of a well designed randomized double blind trial correlating the use of fish oil supplements during pregnancy with the baby's cognitive development and the mother's risk of post partum depression.
Some studies in the past have found a link between higher intake of fish oil and improved cognitive development for the baby along with less incidence of post partum depression for the mother. None of these studies, however, were truly authoritative: some were observational (post facto analysis), while others used small sample sizes. As a result of these studies, many national and international health agencies have come out with recommendations for pregnant women to take fish oil supplements. The key fish oil component is assumed to be docosahexaenoic acid, or DHA.
This study was the first clinical trial of significant size to actually test the causality link between taking fish oil supplements and assumed health and cognitive benefits. It used a double blind randomized trial approach with a statistically large population of subjects. The researchers followed 2,320 women, who were randomly assigned to take 1,500 mg of fish oil pills or of vegetable oil pills (control group), starting on the 21st week of pregnancy. After giving birth, mothers took standard evaluation test for depression 6 weeks and 6 months after giving birth, while 694 children were evaluated at age 6 months.
The conclusions were disappointing. The children's cognitive, language, motor development and social emotional behavior scores were the same across both groups. Of the women in the trial, 9.67% of those who took DHA supplements developed post partum depression, while 11.02% of those in the trial group did. The conclusions of the authors were that DHA supplements did not influence either the baby's cognitive development, of the mother's risk to develop post partum depression, although there appeared to be some positive influence for women at high risk. The researchers conclude: "The results of [this trial] do not support routine DHA supplementation for pregnant women to reduce depressive symptoms or to improve cognitive or language outcomes in early childhood."
Why is the outcome of this study so unexpected to many? Some experts, such as Dr. Emily Orken of Harvard Medical School, suggest that dosage might be a possibility. Some mention that eating fish may be better than taking supplements. The study authors suggest that previous observational studies have other impacting factors, and that past clinical trials might have used too small population samples. Finally, some, like Dr. William Barth of Massachussetts General Hospital, were skeptical all along: “I wish it were so simple, that there was a pill we could take to make our children smarter.”
The study was considered important enough by the Journal of the American Medical Association to warrant an editorial. This editorial recognizes the value of the study, yet suggest that, for now, recommendations to pregnant women not be changed: "For now, pregnant women should take care to get the recommended intake of 200 mg/d of DHA, either by including low-mercury, high-DHA fish in their diets or by taking a daily n-3 PUFA supplement," write Dr. Emily Orken of Harvard Medical School and Dr. Many Belfort of Children's Hospital in Boston for Editorial Board of JAMA.
Want to read more about it? Try Medical News Today, Reuters, WebMD, Food Consumer, International Federation of Gynecology and Obstetrics, The Age, the New York Times, US News, Time Magazine, Medscape, the LA Times, and ABC News.