Martin Winn's cholesterol level was inching up. Cycling up hills, he felt chest pain that might have been angina. So he and his doctor decided he should be on a cholesterol-lowering medication called a statin. He was in good company. Such drugs are the best-selling medicines in history, used by more than 13 million Americans and an additional 12 million patients around the world, producing $27.8 billion in sales in 2006. Half of that went to Pfizer for its leading statin, Lipitor. Statins certainly performed as they should for Winn, dropping his cholesterol level by 20%. "I assumed I'd get a longer life," says the retired machinist in Vancouver, B.C., now 71. But here the story takes a twist. Winn's doctor, James M. Wright, is no ordinary family physician. A professor at the University of British Columbia, he is also director of the government-funded Therapeutics Initiative, whose purpose is to pore over the data on particular drugs and figure out how well they work. Just as Winn started on his treatment, Wright's team was analyzing evidence from years of trials with statins and not liking what it found.

Yes, Wright saw, the drugs can be life-saving in patients who already have suffered heart attacks, somewhat reducing the chances of a recurrence that could lead to an early death. But Wright had a surprise when he looked at the data for the majority of patients, like Winn, who don't have heart disease. He found no benefit in people over the age of 65, no matter how much their cholesterol declines, and no benefit in women of any age. He did see a small reduction in the number of heart attacks for middle-aged men taking statins in clinical trials. But even for these men, there was no overall reduction in total deaths or illnesses requiring hospitalization--despite big reductions in "bad" cholesterol. "Most people are taking something with no chance of benefit and a risk of harm," says Wright. Based on the evidence, and the fact that Winn didn't actually have angina, Wright changed his mind about treating him with statins--and Winn, too, was persuaded. "Because there's no apparent benefit," he says, "I don't take them anymore."

Wait a minute. Americans are bombarded with the message from doctors, companies, and the media that high levels of bad cholesterol are the ticket to an early grave and must be brought down. Statins, the message continues, are the most potent weapons in that struggle. The drugs are thought to be so essential that, according to the official government guidelines from the National Cholesterol Education Program (NCEP), 40 million Americans should be taking them. Some researchers have even suggested--half-jokingly--that the medications should be put in the water supply, like fluoride for teeth. Statins are sold by Merck (Mevacor and Zocor), AstraZeneca (Crestor), and Bristol-Myers Squibb (Pravachol) in addition to Pfizer. And it's almost impossible to avoid reminders from the industry that the drugs are vital. A current TV and newspaper campaign by Pfizer, for instance, stars artificial heart inventor and Lipitor user Dr. Robert Jarvik. The printed ad proclaims that "Lipitor reduces the risk of heart attack by 36%...in patients with multiple risk factors for heart disease."

So how can anyone question the benefits of such a drug?

For one thing, many researchers harbor doubts about the need to drive down cholesterol levels in the first place. Those doubts were strengthened on Jan. 14, when Merck and Schering-Plough revealed results of a trial in which one popular cholesterol-lowering drug, a statin, was fortified by another, Zetia, which operates by a different mechanism. The combination did succeed in forcing down patients' cholesterol further than with just the statin alone. But even with two years of treatment, the further reductions brought no health benefit.