For far too long, the medical community had assumed that how a person will age is "written in the genes." But the more we know about genetics, our biologic inheritance, the more we know that this is not true. Studies continue to show that for most of us, our lifestyle choices and behaviors have far more impact on longevity and health than our genetic inheritance. Twin studies from Denmark, Finland, the United States and Asia all show the same thing -- about 25 percent of how you age is in your genes and 75 percent is your choices. Genes (the elements that carry inherited information) define your basic biology, but how you interact with the world around you -- whether through food choices, exercise, or social connections -- is how you control the way your genes will affect your body.
More Answers from Michael Roizen, MD