3. Diet soda Although replacing sugary drinks with diet soda seems like a smart solution for keeping weight down -- a heart-healthy goal -- it turns out diet soda is likely a major bad guy when it comes to stroke. Why it's bad People who drink a diet soda a day may up their stroke risk by 48 percent. A Columbia University study presented at the American Stroke Association's 2011 International Stroke Conference followed 2,500 people ages 40 and older and found that daily diet soda drinkers had 60 percent more strokes, heart attacks, and coronary artery disease than those who didn't drink diet soda. Researchers don't know exactly how diet soda ups stroke risk -- and are following up with further studies -- but nutritionists are cautioning anyone concerned about stroke to cut out diet soda pop. What to do Substitute more water for soda in your daily diet. It's the healthiest thirst-quencher by far, researchers say.