Proper diet, exercise and a healthful lifestyle are well-known benefactors to a long, healthy life.
Who you are reflects both what you inherited from your parents (DNA/genes/genetics) and your environment (where you live, your lifestyle, your diet, etc.).
Think of it this way: The humidity and temperature of a room may impact how made-from-scratch bread rises, looks and tastes. Similarly to how the dough’s environment impacts its form, the place that you live and the foods that you eat can impact your genetics and the way they are expressed.