En español | You think of yourself as reasonably healthy, but your doctor has told you that your cholesterol is too high. Should you be taking a cholesterol-lowing drug called a statin to ward off heart disease?

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It sounds like a simple question, but getting a straight answer could prove surprisingly elusive.

Doctors usually urge patients to first try to lower their cholesterol by eating better, losing weight and getting more exercise. But lifestyle changes such as those may not be enough, so statins like Lipitor, Crestor, Zocor and Pravachol — proven lifesavers for those who have already suffered a heart attack — are often prescribed for millions of otherwise healthy people with high cholesterol. It's a practice called primary prevention.

Although a large new British study released yesterday seems to indicate that statins are safe for long-term use, some medical experts question whether the practice really saves lives. And they point out that statins, while generally well tolerated, are not without risks.

The debate over statins is bound to intensify in the coming months. The biggest-selling statin — Lipitor, made by Pfizer — which has been prescribed to more than 17 million people and made more than $100 billion in sales over the past decade, is scheduled to come off patent Nov. 30. Over the next year prices are expected to drop gradually as generic forms of Lipitor become available, which could encourage many more people to use them.

In fact, Crestor at about $5 a pill, soon will be the only remaining statin still under patent. But even if you take cost out of the picture, says Mark Hlatky, M.D., a cardiologist and professor at Stanford University School of Medicine, "you could still have questions about" the use of statins.

"The first question is, 'Does it work and how do the risks and benefits balance out for individual people?' " he says.

Dangers of high doses

That question was highlighted in June, when the Food and Drug Administration (FDA) warned that no new patients should start taking an 80 mg dose of simvastatin — the generic name for Zocor — because it carries a higher risk of serious muscle damage that could lead to kidney failure and death. Meanwhile, a review of five major drug trials showed that high-dose statin users were slightly more likely to develop diabetes than those on a lower dose.

Still, many researchers see statins, which have other effects besides lowering cholesterol, as miracle drugs. Intriguing studies have linked statins to a lower risk of colorectal cancer, rheumatoid arthritis, cataracts and multiple sclerosis. Statin users see fewer kidney complications after serious surgery and have better recovery from brain injury. They also are 60 percent less likely to develop high-grade prostate cancer. Overall, their risk of dying is reduced, largely because of fewer deaths from infection and respiratory illness.

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