Fish oil has become one of the most popular dietary supplements sold in the U.S., and a study published in the Nutrition Journal provides a pretty good indication why so many adults supplement their diets with the omega-3 fatty acids known as docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).

Researchers had 40 healthy middle age and elderly subjects supplement daily with either 3 grams of fish oils or a placebo. After 5 weeks, they were given cognitive performance tests that included working memory and selective attention drills. Subjects who supplemented with omega-3s performed better on these metal tests than those given a placebo.

True Strength Moment: DHA and EPA are considered essential fatty acids, meaning your body cannot produce them. They can only be taken in through diet. If you’re not a fan of seafood, or can’t get fresh fish year round, consider supplementing your diet with fish oil. This study suggests it may be a smart move.