Statins can help to prevent heart attacks for people with high cholesterol and preexisting heart disease, but they may also up your chances of muscle problems and sprains. "Something about statins interferes with muscle performance, and it seems to get worse the longer you're on them," says Dr. Paul D. Thompson, chief of cardiology at Hartford Hospital in Connecticut. To add to the problem, the same mechanism statins use to protect you from heart attacks may also slow down healing the already susceptible muscles. "Statins prevent the collagen in artery walls from breaking down, which leads to heart attacks," he says, "but they also stop your muscles from dissolving the collagen necessary to repair strains and sprains." If you need to take statins, "just go on the lowest dose possible," says Thompson, "and be aware you might have muscle issues."