Fish, they say, is brain food—although it is not evident in some of our friends who claim to be “fish-tarian.”

Dumb friends aside, a new study is supporting the claim that fish-rich diets, particularly the omega-3 fatty acids found in fish—prevents the occurrence of dementia.

The dietary habits of nearly 15,000 people, ages 65 and up, living in seven different countries: China, India, Cuba, the Dominican Republic, Venezuela, Mexico, and Peru, have been examined by scientists.

The American Journal of Clinical Nutrition determined the results, and these revealed an inversely proportional relationship between eating fish and the incidence of dementia.  Such is true in all countries except in India.  According to the researchers, this data goes along with the theory that omega-3 protects our neurons.

But if you’re not really into fish fillets, tuna, or anything with scales that breathe through their gills, you have another option for brain food.  Walnuts, which also contain a lot of omega-3s, might just have the same effect on you.