High levels of omega-3 fatty acids, found in fish oil, help to preserve thinking ability in elderly. Researchers from the National Institute for Public Health and the Environment in Bilthoven found that the results were particularly striking among subjects with high blood pressure or high cholesterol levels. Previous evidence suggests that diets that include omega-3 fatty acids, specifically, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), protect against the development of dementia and Alzheimer's disease. However, the effect of EPA+DHA consumption on thinking ability, or "cognitive function," has received less scrutiny. The researchers evaluated data for 210 healthy men in the "Zutphen Study," who were 79 to 89 years old in 1990 and had normal mental capacity. Their diets were assessed in 1990, and cognitive function was tested in 1990 and again in 1995. It was found that subjects who ate fish had a slower decline in cognitive function than subjects who did not eat fish. The findings suggest that fish consumption and EPA+DHA intake are not significantly related to cognitive impairment but are significantly related to cognitive decline. The researchers therefore recommend the daily consumption of roughly 400 mg of EPA and DHA, found in fish, meat, eggs, leeks, and cereal products. In another second study, involving 2,251 older individuals, researchers from the University of North Carolina at Chapel Hill, showed that high blood levels of EPA and DHA in elderly are associated with less decline in verbal ability.
American Journal of Clinical Nutrition,
April 2007