Once your teeth lose enamel, you can’t get it back since enamel is a mineral substance and your body can’t produce any more of it. However, eating some foods can assist in preserving the enamel that is still healthy. Protein and greens can help reduce tooth decay by keeping enamel strong. Green and black tea (without sugar) can neutralize plaque-causing bacteria. Fat-free and low-fat dairy with high amounts of calcium. Apples, strawberries, cranberries, and kiwis have a lot of vitamin C for good gum health.