The risk of cognitive decline and stroke in older adults may be reduced by eating tuna and other kinds of fish, according to study by researchers in Finland.
The study used a sample of 3,660 men and women aged 65 or older and subjected them to brain scans to look for silent brain infarcts, stroke or dementia. 5 years later, 2,313 members of the sample were tested again with scans, and all participants were given questionnaires on fish in their diets.
Findings of the study showed that participants who ate broiled or baked tuna or other fish high in omega-3 fatty acids (DHA and EPA) three or more times a week were at a 26% lower risk of experiencing the silent brain lesions that cause dementia and stroke than people who were not regular fish eaters. Even one fish meal weekly reduced the risk by 13%, and the study found that regular consumption of these types of fish reduced the changes of white matter in the brains of fish eaters.
“While eating tuna and other types of fish seems to help protect against memory loss and stroke, these results were not found in people who regularly ate fried fish,” said Jyrki Virtanen, PhD, RD, with the University of Kuopio in Finland. “More research is needed as to why these types of fish may have protective effects, but the omega-3 fatty acids EPA and DHA would seem to have a major role.” Types of fish that contain high levels of DHA and EPA nutrients include salmon, mackerel, herring, sardines, and anchovies.
“Previous findings have shown that fish and fish oil can help prevent stroke, but this is one of the only studies that looks at fish’s effect on silent brain infarcts in healthy, older people,” said Virtanen. Research shows that silent brain infarcts, which are only detected by brain scans, are found in about 20 percent of otherwise healthy elderly people.
Source: Neurology, August 5, 2008