Omega-3 fatty acids in fish and fish oil, already known to reduce heart risk, might also help preserve thinking ability, two observational studies have found. The studies, which involved 2,250 middle-aged people and 210 older people, suggest that omega-3s help prevent mental decline possibly by reducing inflammation and promoting the regeneration of nerve cells.

The American Heart Association recommends that most people eat fish at least twice weekly. If you don’t like fish, consider consuming about 2 grams of omega-3s per week. The new studies, published in the American Journal of Clinical Nutrition, add another possible reason to follow those recommendations. Young children and pregnant or nursing women should avoid or limit their intake of species that might be contaminated with pollutants. (For more on safe fish choices, go to Low mercury seafood: How much is safe?)