A new study is underway to see if drinking fresh-squeezed grapefruit juice every day can help prevent osteoporosis. Scientists are optimistic because a recent study in the journal Nutrition found that rats fed grapefruit pulp had greater bone density and a slower rate of bone loss than those that weren’t.

The high antioxidant level in the fruit may be the key, although no one knows for sure. Eight million American women suffer from osteoporosis—a condition in which bones weaken and become more susceptible to fractures—and the lifetime risk is 1 in 2.

Though there is no legal or medical definition, superfoods are nutrient powerhouses that pack large doses of antioxidants, polyphenols, vitamins, and minerals. Eating them may reduce the risk of chronic disease, and prolong life, and people who eat more of them are healthier and thinner than those who don’t. Read about several foods that are considered super, what health benefits they offer, and how to fit them into your diet.