3. Whole grains:
A study in the American Journal of Clinical Nutrition found that men who ate four or more servings of whole grains a day reduced their risk of periodontal disease by 23 percent. Compared to refined carbohydrates (white bread, white rice), whole grains (oatmeal, brown rice) are digested more slowly, causing a steadier rise in blood glucose, says study author Anwar Merchant, D.M.D., Sc.D., an epidemiologist at the University of South Carolina, Columbia. Avoiding spikes in blood sugar tempers the body’s production of inflammatory proteins—and lowers the risk of both gum and heart disease.