“Silent” brain damage may be contributing to a form of dementia or stroke. What happens is that the brain suffers from “silent brain infarcts” when small areas of brain tissue die from an insufficient supply of blood. This subtle form of brain damage is linked to dementia or stroke. Most of the time there are no symptoms and can only be detected by an MRI.
A study used data from 3,660 patients in the Cardiovascular Health study of people 65 and older who underwent at least one brain scan of which 2,313 participants had two scans five years apart. They all completed food frequency questionnaires.
The results indicated that those who ate the most tuna and other non-fried fish had a 26% reduced risk of silent infarcts compared to those eating the least, less than one serving a month. For each additional servings of tuna or other baked/broiled fish the risk of infarct fell by 7%. Those eating at least three servings of fish per week also scored 10.6% better on a test of white matter in the brain. No protective effect was seen from fried fish like fish sticks made from pollack or cod. The authors speculated that the higher omega-3 content of the protective fish such as tuna was involved as pollack or cod is typically low in omega-3 fatty acids.
EPA and DHA (eicosapentaenoic and docosohexaenoic acids), respectively, are two omega-3 fatty acids that have been shown in precious studies to be linked to lower risks of dementia and Alzheimer’s disease. The authors concluded: “Our findings suggest that the prevention of subclinical infarcts and white matter anomalies may be one mechanism by which fish or omega-3 fatty acid consumption may decrease the development of these debilitating conditions”. This study was published in the journal Neurology, August 5, 2008.