Eating fish, chicken, nuts, salad dressing and other foods that contain omega-3 fatty acids may lower blood levels of a protein related to Alzheimer's disease and memory problems, a new study finds.
Researchers, writing in the journal Neurology, said their findings indicate the more omega-3 fatty acids a person takes in, the lower his or her blood levels of beta-amyloid deposits – substances linked to Alzheimer’s disease.
"While it's not easy to measure the level of beta-amyloid deposits in the brain in this type of study, it is relatively easy to measure the levels of beta-amyloid in the blood, which, to a certain degree, relates to the level in the brain," said lead researcher Dr. Nikolaos Scarmeas, with Columbia University Medical Center in New York and a member of the American Academy of Neurology.
For the new study, researchers tracked 1,219 people older than age 65 – gathering information about their diets and testing their blood for beta-amyloid levels. Researchers also examined 10 nutrients, including saturated fatty acids, omega-3 and omega-6 polyunsaturated fatty acids, mono-unsaturated fatty acid, vitamin E, vitamin C, beta-carotene, vitamin B12, folate and vitamin D.
They found study participants with diets high in omega-3 fatty acids had the lowest blood beta-amyloid levels. Consuming just one gram of omega-3s per day – the amount in a half a fillet of salmon per week -- boosted beta-amyloid levels up to 30 percent.
"Determining through further research whether omega-3 fatty acids or other nutrients relate to spinal fluid or brain beta-amyloid levels or levels of other Alzheimer's disease related proteins can strengthen our confidence on beneficial effects of parts of our diet in preventing dementia," said Scarmeas.
The study was funded by the National Institute on Aging.