Researchers at Columbia followed more than a thousand cognitively healthy adults over age 65, asking them questions about their diets and running blood tests for beta amyloid, which forms amyloid plaques in people with Alzheimer's.
The more omega-3 fatty acids a participant ate during the study, the lower her blood levels of beta amyloid, even after adjusting for other factors, including age, weight, and the status of APOE, the gene that's been associated with Alzheimer's. Researchers didn't find a similar association with any of the other nutrients they were looking for, including vitamin E and vitamin D.
Not a big seafood fan? Researchers said that just half a filet of salmon per week was associated with a 20 to 30 percent drop in beta amyloid levels. Or, if even that much fish is too much, nuts and chicken are also good sources of omega-3s.