April 19, 2007
Omega-3 Fatty Acid May Help Prevent Alzheimer's Brain LesionsTopics: Medical Science News
UC Irvine scientists have discovered that Docosahexaenoic acid (DHA), a type of omega-3 fatty acid, may slow the growth of two brain lesions that are hallmarks of Alzheimer's disease. The finding suggests that diets rich in DHA can help prevent the development of Alzheimer's disease later in life. DHA is one of three principle omega-3 fatty acids found mainly in seafood and particularly in fatty, cold-water fish like salmon, sardines, mackerel and herring. Eicosapentaenoic acid (EPA), a second principle omega-3 fatty acid, is also found mainly in seafood, while alpha-linolenic acid (ALA), the third principle omega-3 fatty acid, is found in flax seed and its oil. DHA, EPA. and ALA are also found in smaller varying amounts in algae and other water-based plants:
[...] This study with genetically modified mice is the first to show that DHA, an omega-3 fatty acid, can slow the accumulation of tau, a protein that leads to the development of neurofibrillary tangles. Such tangles are one of two signature brain lesions of Alzheimer's disease. DHA also was found to reduce levels of the protein beta amyloid, which can clump in the brain and form plaques, the other Alzheimer's lesion.Continue reading here ...
Previous studies have shown that DHA may have therapeutic value for Alzheimer's patients, but this research is among the first to show that it may delay the onset of the disease. DHA is found in fish, eggs, organ meats, micro-algae, fortified foods and food supplements.
[...] Mice in three test groups were given food with a 1:1 ratio of omega-6 fatty acids to omega-3 fatty acids. One of these groups received supplemental DHA only, and two groups received DHA plus additional omega-6 fatty acids. After three months, mice in all of the test groups had lower levels of beta amyloid and tau than mice in the control group, but at nine months, only mice on the DHA diet had lower levels of both proteins. These results suggest that DHA works better on its own than when paired with omega-6 fatty acids.
The scientists also determined the mechanism by which DHA leads to lower levels of beta amyloid. DHA, they found, leads to lower levels of presenilin, an enzyme responsible for cutting beta amyloid from its parent, the amyloid precursor protein. Without presenilin, beta amyloid cannot be generated. When clumped into plaques, beta amyloid disrupts communication between cells and leads to symptoms of Alzheimer's disease.
Related: Beware the Omega-3 Bait-and-Switch -
... Many food manufacturers engage in a bait-and-switch tactic that exploits consumers' understandable confusion regarding the distinctions between types of omega-3s.
The labels on many food packages now proclaim, proudly, that the product is rich in omega-3s. However, most of these products are not fortified with the long-chain omega-3s found only in fish and other seafood, which are the only kind proven to confer preventive health benefits regarding the brain, heart, and overall health. (The terms "long-chain" and "short-chain" refer to the number of carbon atoms in the omega-3 molecules in seafood and plants, respectively.)
Instead, most manufacturers fortify their foods with short-chain, plant-derived omega-3s. These substitutes, though better than nothing, are not proven to confer the strong health benefits associated with long-chain "marine" omega-3s. And, while the body can convert them to long-chain omega-3s, the amounts produced are very small.For readers that either don't eat cold water fish or don't eat it often enough, I recommend only one brand of fish oil supplement - Carlson's Liquid Fish Oil (it comes in a pleasant-tasting lemon flavor - use the capsule form if you can't handle taking the liquid)
Cross posted from Hyscience
Posted by Richard at April 19, 2007 8:03 PM
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