Seven months later, researchers used ultrasound to measure fatty deposits and the thickness of the participants’ artery walls. The TM group had a decrease in artery wall thickness, which could reduce heart attack risk by up to 11 percent and stroke risk by up to 15 percent. Artery wall thickness increased in the education group (Stroke, 2000). There’s “very strong evidence from this and other studies that meditation has health-promoting effects,” says Prevention advisor John Astin, PhD, assistant professor at the University of Maryland School of Medicine in Baltimore. And benefits could extend to all ethnic groups. To learn more about transcendental meditation, visit their Web site. More from Prevention: 3 Weird Ways to Meditate