‘No valid conclusions’: Omega-3 trade body fires back over prenatal DHA supplementation findings

A randomised trial follow-up found little benefit of prenatal DHA supplementation on the IQ of children at age seven, academics in Australia have reported.

But trade body the Global Organization for EPA and DHA Omega-3s (GOED) said it had significant concerns about its scientific validity, arguing the experimental design failed to include measurements for omega-3 status at any time for either the mothers or the offspring

The long-term study has been undertaken by Dr Maria Makrides and colleagues from the South Australian Health and Medical Research Institute, Adelaide.

The team randomised pregnant women to receive 800mg of DHA daily or a placebo during the last half of pregnancy and found no group differences in cognitive, language, and motor development at 18 months of age.

At four years of age they claimed there was no benefit of DHA supplementation in general intelligence, language, and executive functioning, and a possible negative effect on parent-rated behavior and executive functioning.

This follow-up was designed to evaluate the effect of prenatal DHA on IQ at seven years, the earliest age at which adult performance can be indicated, they noted in the Journal of the American Medical Association (JAMA).

Of those eligible, 543 children (85%) participated in the follow-up. Average IQ of the DHA and control groups did not differ (98.31 for the DHA group vs 97.32 for the control group), said the researchers.

They added direct assessments consistently demonstrated no significant differences in language, academic abilities, or executive functioning.  

Although perceptual reasoning was slightly higher in the DHA group, parent-reported behavioural problems and executive dysfunction were worse with prenatal DHA supplementation, they claimed.

Experimental design

However, the findings from Australia were criticised by Harry Rice, PhD, VP of scientific and regulatory affairs at GOED. He told us: “ I don't think there's any way the investigators can draw any scientifically valid conclusions given that the experimental design failed to include measurements for omega-3 status at any time for either the mothers or the offspring. Among other things, it's unknown if mothers and/or offspring were receiving a sufficient dose of DHA. “

The organisation fears post-pregnancy diets of mothers (if breastfeeding) and offspring, as well as their omega-3 status, could skew any results.

The Council for Responsible Nutrition in the US raised similar concerns, while also reiterating the broader benefits of omega-3.

Duffy MacKay, senior vice president, scientific and regulatory affairs, said: “Every human has a basic nutritional need for omega-3 fatty acids, and pregnant women are no exception. In fact, pregnant women are an at-risk population for which shortfalls of any nutrient, including omega-3s, can lead to devastating effects. The benefits of omega-3 fatty acids for overall health of both mother and child are numerous, but first and foremost, they are critically important for brain and eye development.

“Recommendations for pregnant and breastfeeding women to consume adequate levels of DHA, a type of omega-3 fatty acid, by the March of Dimes and the American Academy of Pediatrics, respectively, reinforce the importance of this nutrient.”

 

Source: JAMA

“Seven-Year Follow-up of Children Born to Women in a Randomized Trial of Prenatal DHA Supplementation”

doi:10.1001/jama.2016.21303

Authors: Maria Makrides, et al.