Caffeine from coffee and tea, blueberries, fish, whole grains, and dark chocolate can increase brain activity. Blueberries help protect the brain from oxidative stress and may reduce conditions like dementia and Alzheimer's. Fish contains omega-3 fatty acids essential for brain function and development. Whole grains provide dietary fiber and vitamin E to reduce cardiovascular disease risk. Dark chocolate helps maintain the health of small blood vessels and connective tissue in the brain.