A recent study done in Japan determined that consuming dairy products containing lactic acid (milk, yogurt, cheese, etc.) can lower your risk for gum disease. The participants who consumed 55 grams or more of yogurt or lactic acid drinks a day had lower incidence of periodontal disease. The study found that eating milk and cheese did not have as much positive results. The researchers hypothesized that the acid has probiotic effects that could link to healthier gums.
The study also found several other food and drink items that can contribute to positive dental health: black tea (minus sugar, lemon, or milk), and foods high in vitamin C (citrus fruits, tomatoes, broccoli) .