Omega-3s may not give kids 20/20 vision, says study

19-Apr-2011 - Last updated on 20-Apr-2011 at 12:42 GMT

Now cover one eye and read the line underlined in red...

Supplements containing the omega-3 DHA (docosahexaenoic acid) during pregnancy may not improve the eyesight of the infants, says a new study from Australia.

No difference in the clarity of vision was observed between children born to mothers taking a vegetable oil supplement or those taking an 800 milligram daily DHA supplement during pregnancy, according to results of a double-blind, randomized controlled trial published in the American Journal of Clinical Nutrition.

“The results of this study indicated that it is not possible to endorse routine DHA supplementation in pregnancy for the improvement of infant visual acuity at four months of age,” wrote Lisa Smithers, Robert Gibson, and Maria Makrides from the Women’s and Children’s Health Research Institute in North Adelaide.

Don’t dismiss DHA: GOED

Commenting on the study, Harry Rice, PhD, VP Regulatory & Scientific Affairs for the Global Organization for EPA and DHA Omega-3s (GOED) told NutraIngredients-USA that the new study’s findings should not detract from the “large body of scientific evidence in support of long-chain omega-3 supplementation during pregnancy”.

Dr Rice noted that many organizations and government agencies recommend omega-3 supplementation for pregnant women, including ISSFAL (International Society for the Study of Fatty Acids and Lipids, 200 mg/day), March of Dimes (200 mg/day), EFSA (European Food Safety Agency, 350 - 450 mg/day), and the FAO/WHO Expert Consultation (at least 200 mg/day).

“Regardless of the effects of maternal supplementation on visual development, a large body of scientific evidence exists supporting a role of DHA in normal visual development of infants,” said Dr Rice. “EFSA has reviewed the science and provided a positive opinion on the following claim-‘Docosahexaenoic acid (DHA) intake contributes to the normal visual development of infants up to 12 months of age’,” he added.

Study details

The Adelaide-based researchers behind the Australian study, known as the DHA for Maternal and Infant Outcomes (DOMInO) trial, also note that they found no evidence that this relatively high DHA dose adversely affected the infants’ eyesight – an important fact supporting the safety of DHA supplementation.

Prof Makrides and her co-workers randomly assigned 185 women to consume a daily DHA supplement (Incromega 500TG, Croda Chemicals) or a vegetable oil placebo capsule from the half-way point of their pregnancy until the delivery of their child.

Results showed no significant differences between the children of mothers from the DHA or vegetable oil groups. The only factor that was found to affect the clarity of vision of the infants was if the mother was a smoker – the infants of smokers were found to have poorer eyesight.

“DHA supplementation in women with singleton pregnancies does not enhance infant visual acuity in infants at 4 mo of age,” wrote the researchers.

“We are implementing follow-up studies of the [study’s] children to examine whether other areas of child development are influenced by DHA supplementation in pregnancy,” they concluded.

Conflict?

Earlier findings from the same study, published in the Journal of the American Medical Association (Vol. 304, Issue 15), indicated that the daily 800 mg dose of DHA did not lower levels of postpartum depression in mothers, nor did it improve the cognitive and language development in their offspring.

Challenges to DHA are not limited to the scientific community. The EFSA claim reference by GOED’s Dr Rice was recently defended from a challenge from certain Members of the European Parliament (MEPs) to prohibit the EFSA and European Commission (EC)-approved DHA omega-3 eye health claim on breast milk substitute products.

The vote means Mead Johnson’s claim: "DHA intake contributes to the normal visual development of infants up to 12 months of age" can now enter the EU legislature and be used on breast milk substitute products like follow-on formulas aimed at infants between the ages of 6-12 months.

Infant formulas aimed at 0-6 month-olds will not be able to carry the claims and must continue to contain statements about the superiority of breast feeding.

Source: American Journal of Clinical Nutrition
Published online ahead of print, doi: 10.3945/ajcn.110.009647
“Maternal supplementation with docosahexaenoic acid during pregnancy does not affect early visual development in the infant: a randomized controlled trial”
Authors: L.G. Smithers, R.A. Gibson, M. Makrides