It also contains flavonoids that increase blood flow to the brain. Leafy Greens Spinach, kale, and broccoli are excellent sources of vitamins A, C, K, and folate – nutrients that promote healthy brain function. Nuts and Seeds Almonds, walnuts, flaxseeds, chia seeds – these tasty treats contain high levels of antioxidants like vitamin E that reduce oxidative stress on the brain.