People who eat a diet rich in omega-3 fatty acids may significantly lower their risk of developing memory problems and Alzheimer's disease, a new study has found.
Researchers recruited 1,219 people over age 65, and followed their dietary habits for more than a year. Then they tested the subjects' blood for a protein called beta-amyloid, a protein is associated with memory problems and Alzheimer's disease. In fact, plaques and tangles which are found in the brains of Alzheimer's patients are actually clumps of this substance.
"We know that the amyloid mechanisms are out of control in a person with Alzeimer's disease," said the study's lead author, Dr. Nikolaos Scarmeas, associate professor of clinical neurology at New York's Columbia University Medical Center.
"We wanted to see if different nutrients influenced those levels."
Interestingly, the people in the study who consumed omega-3 had significantly lower levels of amyloid in their blood.
The effects are continuous researchers say. The levels decreased by 20-to 30% for each gram of omega-3 fatty acid added to their diet. One gram is equivalent to a handful of walnuts, or half a piece of salmon.
"The more you eat, the lower the amyloid level will be," said Scarmeas.
The study -- published in the medical journal of the American Academy of Neurology - also evaluated beta-carotene, vitamin D, vitamin B12, vitamin E, omega-6, saturated fatty acids, and non-unsaturated fatty acids in the participants diets.
Omega-3 was the only nutrient that showed an association with lower amyloid levels.
A 2010 study found that people who ate food high in omega-3 acids had a nearly 40% lower risk of developing Alzheimer's compared to people who didn't. However, the reason why couldn't be determined. Researchers believe this new study may help explain the connection.
Foods rich in omega-3 fatty acids are often the crux of a Mediterranean diet. Choose fatty fish like mackerel, trout, herring, tuna or salmon. Non-fish options include kale, tofu, soybeans, walnuts and flaxseed.
Although it is best to get nutrients from natural resources, omega-3 supplements can also be effective. Consult with your doctor before adding fish oil supplements to your diet because they may interact with other medications.