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The complex relationship between omega-3 fatty acids and early neurodevelopment

University of British Columbia

Docosahexaenoic acid (DHA, 22:6ω-3) is an omega-3 fatty acid that is an important component of neural lipids accumulating in neural tissue during development. Decreased brain DHA is accompanied by increased 22:4ω-6 and 22:5ω-6, which has been shown to lead to deficits in neural function. However, dietary and other variables may impact DHA status and the potential for early deficiency to have lasting adverse effects on neurodevelopment remains unclear. Therefore, the effect of prenatal DHA and children’s DHA intake and status on neurodevelopment was examined. Pregnant women, n=271, were enrolled at 16 wk gestation and randomized to 400 mg/day DHA or placebo until delivery. Infant neurodevelopment was assessed at multiple time-points until 18 mo. Children returned for follow-up between 5-6 y (n=98). An additional group of 187 children (5-6 y) was enrolled at the same time to increase the sample size. Venous blood was collected, diet was assessed by food frequency questionnaire, and neurodevelopment was assessed. Infants from the placebo group were less likely to achieve high neurodevelopmental test scores up to 18 mo than infants from the DHA group (OR=2.23-3.22, P<0.05), suggesting that fetal DHA inadequacy occurred in our population. No differences were detected in children (5-6 y, n=98) from the placebo and DHA groups achieving a high neurodevelopment test score (P>0.05). However, child DHA intake and status (n=98) were related to the mother’s intake and status during pregnancy. For all children (n=285), DHA intake was positively associated with erythrocyte DHA. Child DHA status was associated with neurodevelopment test scores, but only short-term memory was associated with dietary DHA. These results suggest that DHA low enough to constrain infant neurodevelopment to 18 mo does occur among pregnant women in Vancouver, but the long-term effects remain unclear. We also provide evidence that DHA status is related to cognitive performance in young children. However, the association of maternal and child DHA intake and status limits the interpretation of whether DHA before or after birth is important. Finally, the variability in erythrocyte DHA was high, raising questions about the relationship between DHA intake and other fatty acids, DHA status, and neural function.

Text

2015-10-24

Attribution-NonCommercial-NoDerivs 2.5 Canada

http://hdl.handle.net/2429/54842

Human Nutrition

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/2.5/ca/