Eating a diet high in omega-3 fatty acids — from fish, soy, nuts, or even high-quality supplements — may help ward off Alzheimer’s disease, the authors of a recent study published in the journal, Neurology, suggest.
Researchers from Columbia University Medical Center in New York, studied 1,219 people over age 65 who were free of dementia. The participants filled out questionnaires about their eating habits for the previous 1.2 years. The researchers focused on the participants’ dietary intake of 10 different nutrients, including saturated fatty acids, omega-3 and omega-6 polyunsaturated fatty acids, monounsaturated fatty acid, vitamin E, vitamin C, beta-carotene, vitamin B12, folate and vitamin D.
The researchers also took blood samples from the participants to test for levels of beta amyloid, a protein generally considered to be the most definite link to the likelihood of a person developing brain diseases such as Alzheimer’s. Because beta amyloid is difficult to measure in the brain, the researchers instead used blood levels, which are thought to be a marker for Alzheimer’s risk.
They found that the more omega-3s a person consumed, the lower their blood levels of beta amyloid.
Specifically, consuming 1 more gram of omega-3 fatty acids a day, on top of the average amount of omega-3s consumed in the study, is linked with a 20 to 30 percent decrease in beta-amyloid levels in the blood. One gram of omega-3 fatty acids can be obtained by eating half a salmon fillet once a week.
Out of all the nutrients studied, only omega-3 consumption was associated with lower beta amyloid levels. The results were consistent even after researchers accounted for the participants’ age, gender, ethnicity and educational background.
The beneficial impact of omega-3s on brain health would fall in line with past studies of the nutrient, according to study author, Dr. Nikolaos Scarmeas. Omega-3s have long been associated with positive benefits for memory and cognition.
Scarmeas speculated that omega-3s may be able to reduce oxidative stress on the brain and the resulting vascular damage, or even have some kind of impact on beta-amyloid in the brain. “There is no threshold here,” says Scarmeas. “The more omega-3s one eats, the less the beta amyloid levels are.”