High doses of fish oil supplements in pregnant women improved eye and hand coordination in their babies at age 21/2 years, according to a randomized controlled trial published Dec. 21.
Researchers said their trial (Arch. Dis. Child. Fetal Neonatal Ed. 2006 Dec. 21 [Epub doi 10.1136/adc.2006.099085)] is the first to show improvements in eye-hand coordination with fish oil supplements, and said the results suggest that research into the beneficial effects of fish oil supplementation during pregnancy may require higher dosages.
“These preliminary data indicate that supplementation with a relatively high-dose fish oil during the last 20 weeks of pregnancy is not only safe but also seems to have potential beneficial effects that need to be explored further,” wrote the researchers, led by Jan Dunstan, research fellow with the University of Western Australia's school of pediatrics and child health. “Given the scarcity of data to support the efficacy of fish oil supplementation during pregnancy, our data have a potentially important role in informing on the effects of fish oil supplementation on early postnatal infant development.”
The researchers randomized 52 pregnant women into a group supplementing their diets with 2.2 g of docosahexaenoic acid (DHA) and 1.1 g eicosapentaenoic acid (EPA) per day. A control group of 46 received olive oil supplements. Women were excluded from the study if their normal diet exceeded two meals of fish per week.
The researchers measured phospholipids in the red blood cells of the cord blood of the babies, and conducted tests measuring the babies' development at 21/2 years.
Of the 72 babies that made it to the follow-up at 21/2 years, all of the babies in the intervention group had significantly elevated DHA and EPA levels and significantly lower levels of arachidonic acid in their cord blood, compared with the control babies.
At 21/2 years (mean age of 34.7 months), researchers could not identify significantly higher scores for the 33 babies in the fish oil group in growth, development, receptive language, and behavior, except for the eye and hand subscale of the Griffiths Mental Development Scales. On the eye and hand subscale, the intervention group's mean score was 114, compared with 108 for the control group.
“Although the underlying mechanism is not understood, DHA is known to facilitate rapid phototransduction in the retinal membrane, and deficiencies are associated with reduced retinal function in infant primates,” the researchers write. “Furthermore, effects on visual evoked potential could indicate that DHA may also have an effect on the development of the visual cortex.”
The researchers said the small size of their sample is a weakness of the study. Although theirs could be a chance finding, they said they found no adverse effects of fish oil supplementation in any of the measures of development.