In one study, 1,219 people over age 65 without dementia gave doctors information about their diets for 14 months and then took a blood test.
Researchers found a hopeful link: As the levels of omega-3s in the diet increased, blood levels of beta amyloids decreased. Those who consumed 1,000 mg above the average for omega-3s per day—equal to a half-serving of salmon—had 25 percent lower blood levels of beta amyloids than those who got an average amount of omega-3s. Doctors said that regardless of age, gender, race, daily calories, or whether the person had a gene variation, ApoE, that made them more likely to develop AD, everyone benefited equally from omega-3s.