Jennifer Loftus did everything she could think of to bring down her high cholesterol. But nothing - not diet, not exercise, not even natural supplements - helped her control the problem.

After six years of trying, the otherwise healthy 36-year-old nurse from Marlton was ready to take her doctor's advice: start a lifelong, daily regimen of cholesterol-lowering statins.

It's what millions of Americans do - turning statins into huge moneymakers for drug companies.

The cholesterol-lowering drugs have been shown in clinical studies to reduce the risk of death, heart attack and other problems in patients with cardiovascular disease, but it is less clear that they help patients such as Loftus who don't yet have heart disease.

"It is a very common response - not just of primary-care doctors, but also cardiologists - that everybody with high cholesterol is put on a statin," said David Becker, a Flourtown cardiologist.

Becker thinks that quick-fix approach has led to the drugs' overprescription.

Now a recent study that compared two cholesterol drugs has many patients and doctors asking the same thing.

The study compared the combination drug Vytorin - a mix of two cholesterol busters, Zetia and Zocor - to Zocor alone. It found that Vytorin did not do better than Zocor in preventing the buildup of arterial plaque.

Vytorin is made by a Merck and Schering Plough partnership aimed at adding a new cholesterol drug to the market as Merck's Zocor went generic. Zetia blocks cholesterol absorption in the stomach, while Zocor limits cholesterol production in the liver.

The buildup of plaque from too much cholesterol can lead to heart attack and stroke. It has long been assumed that by lowering cholesterol, patients would lessen their risk of death - even in people without heart disease.

But analyses of studies that compare otherwise healthy patients on statins with those not taking the drugs reveal that dozens of people must be treated with the medications over many years to avoid a single heart attack or other "major coronary event."

Between 200 and 250 people with high cholesterol but no known cardiovascular disease must take the drugs daily for three to five years to prevent one death, two analyses of the available scientific literature reveal.

On the other hand, if 68 such patients followed a more careful diet, one death could be avoided, according to a similar analysis that tracked patients for an average of more than 61/2 years.

Becker's office was among those deluged by calls from worried patients in the two weeks since the Vytorin study was released.

In almost every case, he persuaded his patients to stick with their meds.

Becker isn't concerned about the safety or even the efficacy of Vytorin, which did lower so-called bad LDL cholesterol more than Zocor alone.

But he wonders whether the long delay in the release of the Vytorin study was because the companies weren't eager to publicize the less-than-stellar results.

The study reported no significant difference in the buildup of arterial plaque after two years. For some, that raised the question of just how important it is to lower cholesterol.

Given the financial stakes - cholesterol-lowering drugs generated $21.6 billion from U.S. sales in 2006 - some wonder whether studies that question the benefits of the medications ever reach the public.

Last week, a New England Journal of Medicine article found that nearly one-third of the studies of antidepressant drugs were never published. The results of unpublished studies tend to be more negative.

Loftus is getting married in March and hopes to get pregnant. So before taking statins, she went to get a second opinion from Daniel Rader, a University of Pennsylvania cardiologist and cholesterol expert.

She was surprised by his recommendation.

Rader told her to hold off on the drugs and give diet and exercise another shot. He sent her to a nutritionist.

"I rarely put new patients on a drug on their first visit and almost always counsel lifestyle changes," Rader said. "It really comes down to an individual patient and assessing their personal risk of developing cardiovascular disease not just for the next 10 years, but for 20 to 30 years."

While Loftus has a total cholesterol of 254 and a "bad" LDL cholesterol of 185 - both well above the recommended levels - she has few other risk factors for heart disease.

But every patient is different.

That same morning, Rader and a colleague had persuaded - after months of trying - a retired computer programmer from Roxborough that it was time for him to go on a statin.

Kai Schroeder is 61; his total cholesterol was 206, and his LDL was 132. But in addition to his age and gender, Schroeder had vascular disease.

Rader said that given his risk factors for developing a life-threatening problem, Schroeder's need to be on the medication was a "no-brainer."