EDITORIAL

Forget About Smarter Kids …
Get Ready for Postpartum Depression

J ust a few days ago, I received a notice from the Journal of the American Medical Association (JAMA) to renew my subscription. It ended up in my wastepaper basket. Then, while looking at the latest issue, my decision was reinforced. In it was a lead article about DHA fish oil supplementation, maternal depression, and the neurodevelopment of young children. Based on my knowledge of prior research, the paper seems to have escaped JAMA’s peer-review process—a clear reminder why I’m learning to live without it.1

In this double-blind, multicenter, randomized controlled trial, the researchers found that consumption of DHA-rich fish oil supplements given from mid-term to delivery does not reduce postpartum depression in mothers or improve cognitive or language outcomes in children up to 18 months.

The Wrong Signal

Given the undisputed importance and critical nature of omega-3 oils during pregnancy and the use of DHA as a necessary structural component in the brain and retina, the principal findings of this study are troublesome. It simply gives the wrong signal to many women, who might through the advice of their physicians, or through poor press coverage, choose not to supplement with fish oil during pregnancy. That would be a grave mistake.

DHA Importance: Before, During and After Pregnancy

The Institute of Medicine (IOM)* recommends fish oil supplements for both pregnant and lactating women in the range of 200–300 mg of DHA daily, throughout pregnancy and not starting at mid-term. IOM reports that infants whose mothers consumed DHA and EPA during pregnancy may gain the benefits of longer gestation, and better vision and brain development. So why did the researchers of the JAMA study not give DHA throughout their entire pregnancy? We know that folic acid will not prevent neural tube defects, unless given during the first trimester; it is not effective when given later.


*IOM is the health arm of the National Academy of Sciences, and one of its four National Academies. It is an independent, nonprofit organization that works outside of government to provide unbiased and authoritative advice to decision makers and the public.


Another problem with the protocol is testing brain development at 18 months. Not only is there little prior evidence for successful measurement at this age, the test used is not, in all likelihood, sufficiently sensitive, as even JAMA in an accompanying editorial admits.2 The new study might have shown no benefit in 18-month-olds because effects in infants might be “hard to measure” or “it may be that the benefit of DHA is not as important as when you’re 4.”

In an earlier small study using fish oil during pregnancy, researchers found IQ increases at age 4, although no cognitive benefit was seen in infants or 7-year-olds.3 The lead author of the study thought that perhaps the benefit shown at age 4 also existed at 7, but was difficult to identify among other developmental factors.

“A large body of scientific evidence has established a strong relationship between the DHA status of mothers and infants and a variety of important pregnancy-related outcomes, including infant development,” said Duffy MacKay, N.D., vice president, scientific & regulatory affairs, Council for Responsible Nutrition.4 “Unfortunately in this trial, we have no idea of the DHA status of the mothers at the beginning of pregnancy or when they were evaluated for depression. Further we have no idea of the DHA status of the infants at 18 months when they were evaluated for neurocognitive outcomes. Without measurements of DHA status, it is difficult to draw conclusions from the study and certainly should not provide definitive advice to consumers.”

Many established variables can impact individual DHA status for the mothers and children of both test and control groups in this study. These include differences in synthesizing DHA from other fats, the rate of maternal to fetal DHA transfer, the status of other nutrients required to synthesize DHA, and other dietary sources of DHA. These were not controlled for, nor was the placebo matched for fish odor, thus blowing the identity of the DHA. Plus, without measuring DHA levels, we have no idea how many women took it outside the study.

Also, it is known that maternal DHA status returns to below pre-pregnancy levels within a few weeks from delivery. Consequently, a mother who started the trial with low DHA status would have returned to pre-pregnancy status by the time she was evaluated for depression at six weeks and six months post delivery. The results almost certainly would have been different if fish oil had been taken consistently leading up to, during, and after pregnancy.

This protocol failure also applies to the findings for the infants. There was no information about what they were given in the eighteen month period following birth, whether through breast milk or DHA-enriched formula.

“Essentially, DHA status needs to be adequate throughout pregnancy for women and their infants to receive the many established benefits,” said Dr. MacKay.

Largely Ignored by the Press

Even though the secondary findings were quite positive, showing that women supplemented with DHA had lower incidence of preterm birth and lower incidence of low birth weight offspring, this hardly appeared in the press coverage. For example, the New York Times barely mentioned it, and then belittles its effects.5 These benefits are significantly associated with positive long-term outcomes, including better cognitive development. Fish oil is also important for mothers-to-be for its conferred heart benefits, as well as for reduced inflammation and the promotion brain, skin, bone and eye health.

You can imagine that JAMA, with only drug company advertisements in its pages, is uncomfortable about fish oil’s success, especially because it has so much to offer. It’s a kind of “wonder drug,” but very safe to use, widely available, and very inexpensive. By the way, there is a prescription fish oil product and it sells for $225 for 90 caps, about 16 times more than the supplement form. And it’s noteworthy that a few choice supplements now use the same proprietary process to produce the recently FDA-approved EPA and DHA ethyl esters combination. Go figure!

References

  1. Makrides M, Gibson RA, McPhee AJ, Yelland L, Quinlivan J, Ryan P; DOMInO Investigative Team. Effect of DHA supplementation during pregnancy on maternal depression and neurodevelopment of young children: a randomized controlled trial. JAMA 2010 Oct 20;304(15):1675-83.
  2. Oken E, Belfort MB. Fish, fish oil, and pregnancy. JAMA 2010 Oct 20;304(25):1717-8.
  3. Helland IB, Smith L, Saarem K, Saugstad OD, Drevon CA. Maternal supplementation with very-long-chain n-3 fatty acids during pregnancy and lactation augments children’s IQ at 4 years of age. Pediatrics 2003 Jan;111(1):e39-44.
  4. Anon. CRN responds to JAMA fish oil study—Association reinforces the importance of DHA before, during and after pregnancy. Council for Responsible Nutrition, Washington, DC, October 19, 2010. http://www.crnusa.org/CRNPR10-FishOil101910.html.
  5. Belluck P. Fish oil use in pregnancy didn’t make babies smart. New York Times, October 19, 2010, www.nytimes.com.

FREE Subscription

  • You're just getting started! We have published thousands of scientific health articles. Stay updated and maintain your health.

    It's free to your e-mail inbox and you can unsubscribe at any time.
    Loading Indicator