Keep drinking orange and grapefruit juice. Research from Texas A&M University finds that citrus may protect you from osteoporosis and other diseases. Co-author Bhimu Patil, director of the Vegetable and Fruit Improvement Center, says rats that regularly consumed orange or grapefruit juice showed an increase in bone density and strength compared to those animals that did not drink juice. "We found both grapefruit juice and orange juice help increase the antioxidant activity, which in turn [promotes] bone density."

The antioxidants -- vitamins, minerals and naturally occurring compounds -- are t hought to be effective in helping prevent cancer, heart disease and stroke. But Patil is not sure which compound in citrus is responsible for strengthening bones. "In citrus alone there are 400 active compounds. We need to go further in human beings to determine what happens [with those compounds]," he says

Patil suspects the compound could be limonoid which is the focus of several studies for its potential to prevent various human diseases. Patil says limonoids will be included in the next phase of his study, but notes that with at least 40 different types of the compound it may take a while to identify the active agent.