Sorry Nemo, but eating more fish is an easy way to prevent age-related memory loss, finds recent research published in the American Journal of Preventive Medicine.

Omega-3 fatty acids, rich in fatty fish like salmon, sardines, walnuts, and soybeans, are a nutritional darling. Prior studies have shown they can reduce risk for heart disease, breast cancer, and chronic disease, as well as cut rheumatoid arthritis risk in half and slow down aging.

The latter is what the present study found in relation to memory. Researchers analyzed data from an existing 10-year study that followed 260 adults, ages 65 and older. Participants began the study in 1989 without reported cognitive problems or dementia and were given routine blood tests and an MRI when the study was finished.

One hundred sixty-three participants ate baked or broiled fish at least once a week, whereas 97 participants ate much less. And the results showed those who ate more fish had 14 percent more gray brain matter, which is comprised of the tissue and cells that play a vital role in maintaining healthy memory and cognition. “People have said for a hundred years that fish is brain food, and now we have more evidence that it could be good for health,” Dr. William Harris, a professor from the Sanford School of Medicine at the University of South Dakota in Sioux Falls, told Reuters.

According to The American Occupational Therapy Association, cognitive disorders are a growing problem in the United States, citing the 5.3 million people living with Alzheimer’s in 2010. Up to an additional five million people were living with a form of dementia, a majority of whom were over the age of 65. So the study’s takeaway isn’t just that eating fish benefits your health. It's that memory and cognition suffer as we age, and any preventive measures a person can take are worthwhile.

Is there a catch (pun intended)? According to the American Heart Association (AHA), some fish does contain high levels of mercury and other contaminants. And the AHA says the benefits of eating fish outweigh the risks for older men and women.

Vegetarians and vegans needn’t worry. While the AHA’s recommendation is to eat at least two servings of fish a week, fish oil supplements boost your brain and memory, too. Pay special attention to ingredients to ensure it complies with your diet.

Source: Rail C, Erickson K, Lopez O et al. Regular Fish Consumption and Age-Related Brain Gray Matter Loss. American Journal of Preventive Medicine. 2014.