Omega-3 fatty acids are a family of fats that occur naturally; three of them, α-linolenic acid (ALA), eicosapentaenoic acid, and docosahexaenoic acid (DHA), are important components of the human diet.  Some recent studies have concluded that being deficient omega-3 fatty acids may affect brain physiology and increase the risk of cognitive decline.  Superficially, this claim makes sense.  After all, DHA is abundant in the brain and is involved in numerous critical functions.  ALA, or something that it’s converted into once consumed, exhibits a potent anti-inflammatory effect in the brain.  Finally, DHA might be able to enhance learning and memory processes in the brain.

Dietary intake of omega-3’s, mainly from fish, have been claimed to either slow, or have no effect upon, cognitive decline and the incidence of dementia. The problem is that thus far all of the clinical trials have either included too few patients or were conducted for quite brief periods of time. Thus, the results tended to be rather variable and potentially misleading. Over time, as the studies became more sophisticated and involved more and more patients for longer periods of time, the effects of omega-3s became far less apparent.

Recently, a study published in Alzheimer’s & Dementia followed almost three thousand people (from an initial group of 5600), aged 60 to 80 years, for 40 months. Their daily diets, medications, and health status were carefully monitored. The patients and their controls were carefully matched for education level, smoking habits, alcohol use, etc.

Simply stated, omega-3 intake (as fish or supplement) provided no benefits. Cognitive decline was unaffected. 

What does all of this mean? A single good dietary habit is not enough to provide protection for your brain! Forget about expensive supplements and just eat small amounts of lots of different foods. Avoid almost anything from a cow or pig. Obviously, suggesting that you should not purchase expensive dietary supplements goes against everything that you’ve heard from the people who sell these products. My mantra: Save your money and save your brain.

© Gary L. Wenk, Ph.D. Author of Your Brain on Food (Oxford University Press)

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