Fish Reduces Risk of Dementia and Alzheimer’s

Fish and dementia, alzheimersFish and Omega-3 Fats Reduce Risk of Dementia and Alzheimer’s

Fish consumption has been associated with lower risk of dementia and alzheimer’s. Fish is the best source of omega-3 fatty acids, which have been shown to be essential for neurocognitive development and normal brain functioning.

Several studies have demonstrated that consumption of one omega-3 fatty acid in particular, docosahexaenoic acid (DHA), is important for memory performance.

According to a article by reporter Mollie Martin, over 1,200 patients participated in an epidemiological (population) study showing that people with high DHA levels were 45 percent less likely to develop dementia than people with low DHA levels.

This suggests that proper DHA intake may reduce the risk of developing Alzheimer’s disease.

DHA is the most abundant omega-3 fatty acid in most tissues, and it is present in large amounts in the brain and retina. When an omega-3 fatty acid deficiency exists, the body compensates by replacing it with the corresponding omega-6 fatty acids.

Our ancestor’s diet comprised of equal proportions of omega-3 fatty acids and omega-6 fats. In the past 100 years, Western diets have lowered the ratio of omega-3 to omega-6 to about 1:25.

The following is a November 14, 2006 news release from the United States Department Of Agriculture (USDA), Agricultural Research Service (ARS) by Rosalie Marion Bliss (last modified on 14/8/2007).

People who ate the most fish on a weekly basis – putting them in the top quarter of a study population – were nearly 50 percent less likely to develop the mental deterioration known as dementia over time than participants in any of the other three quarters.

The observational study was led by Ernst J. Schaefer, an Agricultural Research Service-funded scientist. ARS is the U.S. Department of Agriculture’s chief scientific research agency. Schaefer is a physician specializing in nutrition and health with the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University in Boston, Mass.

He and co-authors were looking for a relationship between blood levels of the fatty acid DHA and the risk of developing dementia.

DHA is short for docosahexaenoic acid, a so-called “heart-healthy” omega-3 fatty acid. Several different studies have linked either low DHA, or low fish intake levels, with the incidence of dementia.

The study was published in the November 13 issue of the Archives of Neurology. Schaefer and colleagues analyzed available dietary questionnaires and blood levels of DHA of nearly 900 men and women, aged 55 to 88, who participated in the longitudinal Framingham (Mass.) Heart Study.

At the beginning of a nine-year period, all of the participants were found to be free of dementia.

Using proportional regression analysis, the researchers determined the relative impact not only of blood levels of DHA, but also of potential “confounding” variables such as age, gender, homocysteine and apolipoprotein-E levels, genotype and education.

They found that the participants who reported consuming an average of about three servings of oily fish a week – equivalent to blood levels of DHA at 180 milligrams daily – were associated with a significantly reduced risk of developing dementia of all types, including Alzheimer’s disease.

No other fatty acid blood level was independently linked to the risk of dementia. The study suggests that relatively higher fish consumption over time correlates with a lower incidence of dementia in the over-55 set.

Part of this Article and photo courtesy of the USDA, Agricultural Research Service
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