By Philip A. Ades, M.D., EatingWell Editors, EatingWell for a Healthy Heart Cookbook (2008)

Having multiple factors for heart disease increases your risk exponentially. For example, if you smoke, have high blood pressure or high cholesterol, any one of these factors doubles your likelihood of developing heart disease in the next six years. But having all three increases your chance eightfold. The good news: treating any one of these risk factors effectively—say, you quit smoking or bring your cholesterol into a healthy range—halves your likelihood of developing heart disease (i.e., you’ll have four times, rather than eight times, the risk of someone who doesn’t have any of these risk factors).