Consuming fish has many health benefits, with brain health being one of the most important ones. Fish contain an omega-3 fatty acid called docosahexaenoic acid (DHA), which is important for brain and nervous system function. Research suggests that getting enough DHA may help improve memory, slow cognitive decline, and potentially reduce the risk of Alzheimer's disease later in life. Adults are encouraged to eat approximately 8 ounces of seafood per week, or two 4-ounce servings.
Fatty fish—such as salmon, tuna, trout, and mackerel—are especially good sources of DHA. Many fish provide us with lean protein. Fish is also lower in saturated fat than red meat, which may help support heart health. For vegetarians and vegans, alternatives for consuming DHA include algae-based DHA supplements, flaxseeds, walnuts, and chia seeds. Overall, regularly including omega-3 fatty acids in our diets can support brain function, memory, and overall health.
Source: www.eatright.org/health/essential-nutrients/fats/brain-health-and-fish