Hardly a day goes by anymore without seeing a report exalting a diet rich in omega-3 fatty acids. A diet rich in omega-3 fats has been linked to a wide range health benefits, most notably reduced risk of cardiovascular disease, reduced risk of certain cancers, improved joint health, and improved mood. The typical American diet is very high in red meat, and low in fish. This results in a diet the has a high omega-6 to omega-3 fatty acid ratio, which the opposite of what is believed to be ideal.
Omega-3s have been linked to healthy brain development in humans, but the effects of a diet with a high omega-6 to omega-3 fatty acid ratio on fetal development are largely unknown. A new study has found that a diet low in omega-3 fatty acids may have a negative impact on infant neurological development. 1
The new study involved 135 healthy American women with a diet that was high in meat, but low in fish. The researchers randomly divided the women into two groups; one group received a fatty acid supplement that was the equivalent of adding two fish meals per week, while the other group received a placebo. Both groups of women continued to eat their normal diets. Blood samples were taken from the women during the 16th and 36th weeks of pregnancy and measured for the amount of docosahexaenoic acid (DHA), an omega-3 fatty acid and ethanolamine phosphoglyceride, an omega-6 fatty acid. Sixty days after the babies were born, the researchers used vision tests that evaluate the newborns ability to distinguish lines of different widths; a method of evaluating neurological development in children too young or unable to talk.
The researchers found that the female babies of mothers in the placebo group, had lower than average visual acuity (clearness of vision) than those born to the mothers who received the omega-3 supplement. They also found both male and female children of mothers with high omega-6 levels had below-average vision development. These findings indicate that low omega-3 levels in the mother could possibly affect neurological development of her child. While there is currently no recommendation for the amount of omega-3 that should be eaten during pregnancy, there is a growing body of evidence that indicates it may be important to the child's development. The researchers point out that this study illustrates the importance of eating a wide variety of foods.
1. Innis, S. M. and R. W. Friesen (2008). "Essential n-3 fatty acids in pregnant women and early visual acuity maturation in term infants." Am J Clin Nutr 87(3): 548-57.