2. Cut back on red meat and dairy products
Red meat is a good source of protein as well as essential vitamins and minerals, including B12, iron and zinc. But many cuts are high in unhealthy saturated fats, as are whole-milk dairy products. Saturated fats raise blood levels of the "bad" LDL cholesterol linked to heart disease and impaired memory. Harvard's Tanzi thinks the evidence to limit meat is strong: He's been a vegetarian for years.
Tip: If you can't live in a world without greasy cheeseburgers, indulge occasionally. Meanwhile, choose leaner cuts of beef, such as those with "loin" or "round" on the label, such as sirloin and round roast or steak. Avoid chuck. Other good sources of protein: beans and legumes, such as kidney beans, split peas and lentils. Nosh on an ounce a day of almonds, walnuts or cashews.
3. Ramp up foods rich in omega-3s
Your brain needs a certain amount of fat to function properly. Fats provide energy, help the body absorb essential vitamins and protect nerve cells and connections. But there are good and bad fats, and too much of the wrong kind throws a monkey wrench into the works, speeding the formation of beta-amyloid plaques.
Omega-3s are among the good fats. Research shows that they fight inflammation and support the structure of brain cells. Last year, a report in Neurology by Gene Bowman's team at Oregon Health & Science University found that study participants (average age: 87) who had high blood levels of healthy fats, including omega-3s and a variety of vitamins (including B, C, D and E) and low levels of trans fats had less brain shrinkage and scored better on cognitive tests than those who ate less nutritious diets.
Tip: The body doesn't produce fatty acids naturally, so you must add them to your diet. If you're like most people, you are eating far too many inflammation-promoting omega-6 fatty acids and far too few omega-3s. What to do? In addition to eating more fish, add flaxseed to your cereal and smoothies and chia seeds to stir fries and salads. Both are stuffed with omega-3s (and have little taste). How much should you eat? According to the Cleveland Clinic, one to two tablespoons is a healthy daily dose.
Next page: Choose colorful fruits. »