Fish Oil and Alzheimer's Disease, Dementia

Benefits of DHA

NEW ORLEANS, LOUISIANA. DHA (docosahexaenoic acid), a major component of fish oils, is an absolute requirement for the development of the human central nervous system and the continuous maintenance of brain cell function. DHA is an important part of the plasma membranes of nerve (neuronal) cells and is essential in the maintenance of their fluidity and integrity. It is also involved in the generation of certain metabolites (docosanoids) of which the most important is neuroprotection D1 or NPD1. Both DHA and NPD1 are involved in ensuring membrane stability and fluidity and inhibiting the activation of inflammatory signaling mediators such as cyclooxygenase-2 (COX-2). NPD1 is also beneficial in preventing excessive oxidative stress from degrading DHA. Furthermore, one clinical trial concluded that supplementation with DHA and lutein significantly improved cognitive abilities in elderly people. Researchers in Louisiana sought to determine if there was a significant relationship between DHA and Alzheimer’s disease.

DHA and Alzheimer’s Disease

Unfortunately, as DHA is a highly unsaturated fatty acid, it is subject to lipid peroxidation which, in turn, is associated with retinal and neurological dysfunction and visual and cognitive decline. The free radical initiated oxidation of DHA is also believed to be one of the first steps in the cascade of events (brain cell membrane instability and neural cell dysfunction) leading to Alzheimer's disease with the characteristic formation of amyloid plaques. On the other hand, the DHA metabolite, NPD1 has been found to be neuroprotective by inhibiting oxidative stress, cell death, and inflammation-triggered neuronal decline while promoting brain cell survival and maximizing cognitive function throughout the human lifespan.
Lukiw, WJ and Bazan, NG. Docosahexaenoic acid and the aging brain. Journal of Nutrition, Vol. 138, 2008, pp. 2510-14

Editor's note: There is no question that DHA is crucial for the development and maintenance of the central nervous system and its neuronal cells. This article further suggests that there is a relationship between DHA and Alzheimer’s disease: an adequate DHA supply may also help prevent cognitive decline and progression of Alzheimer's disease. However, since DHA is easily oxidized its intake should always be accompanied by supplementation with vitamin E (gamma-tocopherol) and its regenerator, vitamin C.

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