Compared to people who don’t drink coffee, those who sip 3 or 4 cups a day have 41% less coronary artery calcium (CAC), the study data show. CAC is a well-established marker of heart disease; the more of it you have, the more likely you are to suffer a heart attack. “Even for people who drank one cup a day, there was a reduction in coronary artery calcium,” says study coauthor Eliseo Guellar, MD, of the Johns Hopkins Bloomberg School of Public Health. On the other hand, the benefits of drinking coffee started to reverse among people who drank more than four or five cups a day, Guellar says. It’s not clear exactly how coffee may improve your heart health. But Guellar says there are many antioxidants in java. Some of these may reduce your body’s sensitivity to insulin, or improve cell function—two possible explanations for coffee’s heart-strengthening abilities. MORE: 4 Cups of Coffee Lowers Your Skin Cancer Risk 20% This news may seem confusing for those who remember a time when health authorities thought coffee was bad for your heart. But those old warnings have been contradicted by a wave of recent research. Guellar says his study is one of many papers that have linked moderate coffee consumption to a healthier heart. The key word in that last sentence is “moderate.” That means 3 or 4 8-ounce cups a day, Guellar says. It’s not clear whether decaf coffee offers the same heart benefits as full-strength java. “Our study looked at a South Korean population, where decaffeinated coffee is rare,” Guellar explains. Also, don’t expect any heart benefits if you’re loading your joe with sugar or other unhealthy additives (or even putting butter in your coffee, though some wellness experts swear by it). But if you enjoy coffee, you’ve got another reason to feel good about your habit. MORE: Infographic: Your Body On Coffee
