Walnuts are known for their powerful impact on heart-health. Their rich levels of omega-3 fatty acids help decrease risk of arrhythmias (abnormal heartbeats), triglyceride levels, and lower blood pressure. Now, a new study from the University of California, Los Angeles, suggests adults who consistently eat walnuts can improve their cognitive function, too.

This study is the first large-scale analysis of walnut intake and cognitive function, and it’s the only study to include all of the available cognitive data from two rounds of the National Health and Nutrition Examination Surveys (NHANES): 1988 to 1994 and 1999 to 2002. NHANES "draw from a large sampling of the U.S. population, typically ages 1 to 90 years old” and researchers included adult participants aged 20 and older. Regardless of age, gender, or ethnicity, the results showed higher walnut consumption significantly increased adults' performance on a series of six cognitive tests.

Previously, similar results were achieved in mouse model studies, where eating walnuts promoted brain health and slowed or prevented the progression of Alzheimer’s disease. “It is exciting to see the strength of the evidence from this analysis across the U.S. population supporting the previous results of animal studies that have shown the neuroprotective benefit from eating walnuts,” said Dr. Lenore Arab, lead study author from the David Geffen School of Medicine at UCLA, in a press release.

Arab added the amount of walnuts an adult should eat is realistic, too: It’s less than a handful (13 grams) per day. In addition to omega-3s, walnuts are high in antioxidants, vitamin E, folate, and melatonin. It’s also the only nut to contain alpha-linolenic acid, a kind of omega-3 found in plants. One study found people who ate a diet high in alpha-linolenic acid were less likely to have a fatal heart attack.

"It isn't every day that research results in such simple advice — eating a handful of walnuts daily as a snack, or as part of a meal, can help improve your cognitive health," Arab said.

According to a 2014 study published in the Journal of the American Heart Association, people with poor cardiovascular health are at a higher risk of cognitive impairment, such as learning and memory problems. So walnuts improve cognitive and heart health, which may be a better deal than we realize.

Source: Arab L, Ang A. A cross sectional study of the association between walnut consumption and cognitive function among adult us populations represented in NHANES. The Journal of Nutrition, Health & Aging. 2014.