3.Poultry

Poultry, like chicken or turkey, pack in lean protein, choline, and iron, all of which support cognitive function, research shows. The American Hearst Association suggests opting for lean meat low in saturated fats, like poultry, over red or processed meats to keep your cholesterol at a heart-healthy level.
One serving: 3 ounces
Aim for: 2 servings per week
Try it: Spice-Roasted Chicken With Caramelized Carrots and Shallots
4. Citrus

“Citrus and citrus juice is full of flavanone (plant-based compounds with antioxidant properties), which research shows can improve blood flow to the brain, which in turn improves cognitive function,” says Avena. In fact, one study found that elderly people who eat citrus almost every day are 23% less likely to develop dementia.
One serving: 1 cup
Aim for: At least one serving per day
Try it: Red Citrus Salad