Scientists Crack Open Insights Into How Walnuts Provide Food for Thought

Walnuts have long been linked to better heart health. Research from the David Geffen School of Medicine at UCLA shows these tasty tree nuts may be good for the brain, too. 

Study scientists used data from the National Health and Nutrition Examination Survey, which includes a large sampling of the U.S. population, to connect the dots between walnut consumption and better cognition. The March 2015 study, done with partial funding from the California Walnut Commission and published in the Journal of Nutrition, Health and Aging, found that among people over 60, those who ate 13 grams of walnuts (about 6-7 walnut halves) a day performed better on a series of six brain function tests, including tests of memory, concentration and information-processing speed. "We saw an effect in people who ate a handful of walnuts per day," says head researcher Lenore Arab, a professor of epidemiology at the school.

Scientists haven't yet isolated the walnut's key brain-boosting compounds. "There are numerous possible active ingredients, ranging from the high antioxidant content of walnuts or the combination of numerous vitamins and minerals, as well as the fact that they are the only nut that contains a significant source of alpha-linolenic acid (ALA), a plant-based omega-3 fatty acid," says Arab. Omega-3 fatty acids have been shown to lower risk of heart disease and improve cholesterol, while also relieving conditions such as depression and arthritis. "For now, we just know that walnut eaters in the U.S. population perform better on tests of cognitive function than those who don't eat walnuts." 

Studies in mice have shown that walnuts may prevent or slow the progression of Alzheimer's disease, a finding that may one day be borne out in people, Arab says. Thus, public health researchers have good reason to promote the nut. Says Arab: "It's not every day that research results in such simple advice — that eating a handful of walnuts a day can help improve your cognitive health."