These potent seeds hail from South American countries like Venezuela, Colombia, and more. They may not be as common as peanuts or walnuts, but there's good reason to seek them out at your local health food store or online: "One ounce of brazil nuts, which is about six to eight nuts, has 777 percent of the daily value for selenium, an antioxidant that plays a critical role in DNA synthesis and helps protect our body from oxidative damage and infection," says Alexandra Miller, a corporate dietitian at Medifast. "Inadequate concentrations of selenium may be associated with age-related declines in brain function," she adds. Selenium concentrations in your body naturally decline with age, so load up.

Sesame Seeds

"These are high in calcium and rich in other minerals like iron, magnesium, phosphorous, fiber, and more," says Annie Kay, lead nutritionist at Kripalu Center for Yoga & Health. "Bones are made of more than calcium, so a mineral-rich diet, along with adequate and appropriate movement are a recipe for healthy bones for life." Try using tahini (which is made from sesame seeds) as a base in vinaigrettes or sprinkling a handful or two into pasta salads for a nice element.

"Mushrooms are one of the few foods that naturally contain vitamin D, a vitamin most people don't have enough of," say Lyssie Lakatos and Tammy Lakatos Shames, The Nutrition Twins. "Without vitamin D, you can't properly absorb calcium, which will lead to osteoporosis, broken bones and a hunched spine, and nothing ages you more than that."

Dark Chocolate

Sorry, milk chocolate doesn't count. "Dark chocolate is loaded with flavanols, which are believed to benefit appearance by increasing blood flow to the skin," says nutritionist Mitzi Dulan. "Flavanols also absorb UV radiation, protecting your skin from the damaging effects of the sun." It is high in calories, though, so to avoid weight gain, be sure to eat it in moderate amounts - a square or two as a afternoon treat is all you need.