Cholesterol: How Low Should It Be?
Doctors have long repeated the mantra that when it comes to "bad" low-density lipoprotein, or LDL, cholesterol, lower is better. But two large studies released in the last month are redefining how low is low.
It now appears that reducing LDL to ultralow levels of 60 to 80 milligrams per deciliter of blood significantly reduces heart attacks, strokes, and bypass operations -- and not just for high-risk patients. Healthy people with no evident risks had far fewer cardiac events when LDL dropped below 100 milligrams -- the bottom of the range set by federal guidelines.
That means a lot of people who thought they didn't need to worry may now have to consider reducing their cholesterol level. The easy solution is statins. These wonder drugs, taken by some 11 million Americans, block the liver from processing cholesterol. Under existing U.S. government guidelines, at least 25 million more people with LDL levels above 130 should be on statins. If 100 becomes the new touchstone, statins would almost have to be added to the water supply to cover everyone who would benefit.
But before you run out to start a $100-a-month statin habit, cardiologists advise that you first evaluate your risk factors for heart disease. If both risk and cholesterol are even moderately high, drug therapy may be warranted. But patients must consider that they will likely be on statins for decades, and the long-term health effects of these drugs, if any, aren't known. Cholesterol can be lowered through lifestyle, too, and if your level is only moderately elevated, that might be a solution. "People should try to solve their health problems without drugs whenever possible," says Dr. Richard A. Parker of Beth Israel Deaconess Medical Center in Boston.
It is certainly important to guard against heart disease. According to the American Heart Assn. (AHA), 13 million Americans suffer from coronary artery disease and 1 million die from it each year. The major risk factors are smoking, being overweight, high blood pressure, family history -- and high cholesterol.
Cholesterol, a waxy, fat-like substance, is essential to the production of cell membranes, hormones, and other bodily functions. The body makes some of what it needs, and most of the rest comes from meat and dairy products. Because cholesterol doesn't dissolve in the blood, too much can build up and clog the arteries, increasing risk of heart attack and stroke.
RETHINKING THE REVISE
LDL is one of two types of cholesterol. It's known as the bad kind because it is more likely to accumulate in the arteries. Doctors have long thought that higher levels of "good cholesterol," or high-density lipoprotein (HDL), balance LDL because it carries cholesterol away from the arteries. Based on this thinking, the government revised its guidelines three years ago, raising the danger level for HDL to more than 40 milligrams from more than 35. Under the same guidelines, optimal total cholesterol -- HDL and LDL combined -- is less than 200.
However, recent studies indicate that neither HDL nor the total reading may matter and that patients would be better off focusing on a lower LDL reading. The cardiology community was particularly riveted by a Harvard Medical School study released on Mar. 8 that found that patients with heart disease who took Lipitor, one of the most powerful statins, lowered their LDL to a median of 62, while those on the less potent Pravachol reached a median LDL level of 95. The Pravachol patients may have been well into the optimal range under federal guidelines, but their number of adverse coronary events was 26.3%, compared with 22.4% for the Lipitor group. The death rate among the Lipitor patients was 28% lower than the Pravachol group, evidence that an LDL well below 100 can make a bigger difference than had been thought.
Statins are not without side effects, however. Because they interfere with the liver, patients must be checked at least annually for normal liver function. The drugs can also cause muscle aches and exhaustion. One statin, Baycol, was taken off the market in 2001 because it was associated with a rare and sometimes fatal muscle reaction.
There is another way. Cutting back on butter, egg yolks, and red meat and eating more whole grains and vegetables can make a major difference. "Choosing healthy foods is the best protection from heart disease for the vast majority," says Dr. James W. Anderson, professor of medicine and clinical nutrition at the University of Kentucky. He says that reducing animal fat and increasing fiber can decrease total cholesterol by 40 points or more in just four to six weeks.
Sticking to such a diet isn't easy. A Hong Kong study reported last year demonstrated both the benefits of long-term lifestyle changes and the difficulty of maintaining them. The researchers followed 102 patients at high risk for heart disease for 12 years. All were placed on statins, heart-healthy diets, and exercise plans. Twelve years later, most had stayed on the statins, but only 27 also stuck with the lifestyle changes. Those 27 had less than half the rate of calcium buildup in the arteries as those on statins alone. So while statins do a great job of lowering cholesterol, they can't replace a healthy lifestyle.
By Catherine Arnst