Heart doctors want Americans thinking about cholesterol earlier—and driving it lower—than many are used to. New guidance released Friday from the American College of Cardiology, the American Heart Association, and several other medical groups urges people at risk for heart disease to start actively lowering LDL ("bad") cholesterol by about age 30, reports the New York Times and CNN. The guidelines also suggest tests for LDL levels starting around age 10, which could help identify early those with a genetic condition that puts them at risk for dangerously high levels.