Why are walnuts considered a source of 'brainpower'?

Walnuts and walnut oil are abundant with polyunsaturated fatty acids, which contain more than one double bond in their makeup. These acids make up the majority of the fats in walnut oil and include alpha-linolenic acid and linoleic acid. These are the two essential fatty acids which your body cannot generate. Alpha-linolenic acid (ALA) is an omega-3 fatty acid which the body later reformulates into eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) which are long-chain omega-3 fatty acids that have been found to help prevent deterioration in cognitive function.

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