For the study, researchers followed about 6,800 adults in Iran for five years, starting when the subjects were 50 to 75 years old. All the participants received information on lifestyle habits that can prevent heart disease, like maintaining a healthy weight, avoiding cigarettes, getting plenty of exercise, and eating a diet low in salt, sugar, and fat. Roughly half of them also got a daily “polypill” combining two blood pressure drugs, cholesterol medicine, and aspirin. Overall, 6 percent of the people taking the polypill had a heart attack, stroke, or heart failure by the end of the study, compared with 9 percent of the participants who got only lifestyle advice. That translated into a 34 percent lower risk of events like a heart attack or stroke with the polypill. Even when people took other heart drugs, the polypill was still associated with a 22 percent lower risk of heart attacks, strokes, or heart failure. “In resource-poor settings where many patients cannot afford to buy multiple medications, the polypill has the potential to help prevent heart attacks or heart disease,” says Reza Malekzadeh, MD, the senior author of the study and a researcher at Tehran University of Medical Sciences in Iran. The polypill is available in about 20 countries and costs less than 5 cents a day, Dr. Malekzadeh says. It costs one-fifth what it would cost to take four separate pills. It’s also a convenient option for people who can afford medicines but refuse to swallow four pills a day. In the study, median medication adherence was 80.5 percent in the polypill group. People who took the polypill at least 70 percent of the time — the “high adherence” group — were 57 percent less likely to have a heart attack, stroke, or heart failure during the study than participants who didn’t receive the pill. With high adherence, 21 people would need to take a daily polypill to prevent one person from having a heart attack, stroke, or heart failure. For everyone on the polypill — including people who took it regularly as well as those who took it sporadically — 35 people would need to use the pill to prevent one heart attack, stroke, or heart failure. More than 422 million people worldwide have cardiovascular diseases, and an estimated 17 million people die of heart problems each year, the researchers noted in The Lancet. The idea of combining several drugs to prevent heart problems into a single pill has been around for more than 15 years, the study team notes. Since then, several small, short-term studies in a number of countries have shown a polypill could reduce blood pressure and cholesterol levels. But this is the first study large enough to show that a polypill can prevent heart disease and strokes — and not just risk factors for these events. The polypill included aspirin, Lipitor (atorvastatin), and two drugs to lower blood pressure (hydrochlorothiazide and enalapril). After five years, 202 participants in the polypill group had a heart attack or stroke, compared with 301 people who received only lifestyle advice. Some people on the polypill complained of side effects like dizziness, muscle pain, or indigestion — but these complaints were just as common among people who didn’t receive the polypill. Given how many millions of people worldwide might potentially take the polypill, and how many decades they might be on treatment, longer and larger studies are still needed to be sure the benefits of the polypill outweigh any side effects, says Jeremy Van’t Hof, MD, a cardiology researcher at the University of Minnesota who wasn’t involved in the study. “Until we have more data on the safety of the polypill, those treated with the medications included in the polypill should continue to be monitored by a trained healthcare provider,” Dr. Van’t Hof says. People who do have access to regular primary care — especially in the developed world and more affluent countries — may benefit more from getting screened for high blood pressure and high cholesterol and taking only the drugs they need at the doses they need, says Ian Kronish, MD, MPH, of the center for behavioral cardiovascular health at Columbia University Irving Medical Center in New York City. In low-income countries where most people have little, if any, access to primary care or routine cholesterol or blood pressure screenings, the polypill may make more sense, says Samuel Wann, MD, a cardiologist at Ascension Healthcare in Milwaukee, who wasn’t involved in the study. “Using a polypill to treat high blood pressure and high cholesterol in an entire population is analogous to adding fluoride to the water supply to prevent dental cavities,” Dr. Wann says. “It’s in everyone’s drinking water, regardless of whether or not they are susceptible to cavities.”