VANCOUVER, CANADA. There is substantial evidence that an adequate maternal intake of the long-chain, unsaturated fatty acid DHA (docosahexaenoic acid) is essential to ensure normal development of an infant's central nervous system. DHA along with EPA (eicosapentaenoic acid) are the main components of fish oils. Recent studies have shown that an adequate maternal intake of seafood, especially oily fish, or fish oil supplements improves verbal communication skills at 6 and 18 months of age, reduces the risk of pre-term birth (low birth weight), improves an infant's problem-solving capacity and eye and hand coordination, and results in a higher intelligence quotient (IQ) in children at 4 years of age.
Now researchers at the University of British Columbia report that maternal DHA supplementation also improves visual acuity in infants at 2 months of age. The randomized, double-blind, placebo-controlled trial involved 135 pregnant women (average age of 33 years) enrolled at 16 weeks gestation. Half the group was assigned to receive 400 mg/day of a DHA supplement, while the other half received a placebo containing linoleic and alpha-linolenic acid (265 mg and 40 mg respectively). Blood samples and dietary information were collected at 16 and 36 weeks of gestation. There were no significant differences in the dietary intake (excluding supplements) of fatty acids between the DHA group and the placebo group at 16 and 36 weeks. The DHA concentration in maternal red blood cells rose between weeks 16 and 36 and at week 36 was 32% higher among women in the DHA group.
Visual acuity in the infants was measured at 60 days of age using the Teller Acuity Card Procedure. Results showed that infants born to mothers in the placebo group were 3 times more likely to have a low visual acuity score than were children born to mothers who received DHA supplementation. The proportion of girls having a higher than average visual acuity score was also significantly higher among infants born to mothers who received DHA supplementation. The researchers conclude that mothers who do not receive DHA supplementation during pregnancy have a significant risk of giving birth to an infant with lower than average visual acuity at 2 months of age.
Innis, SM and Friesen, RW. Essential n-3 fatty acids in pregnant women and early visual acuity maturation in term infants. American Journal of Clinical Nutrition, Vol. 87, 2008, pp. 548-57