Don't

By ANDREW PURVIS

Nothing is more appealing than a simple solution to a complex problem. That is why so many people have eagerly embraced the notion that eating right can prevent heart disease. Following the advice of the U.S. Government's National Cholesterol Education Program (NCEP), millions of Americans have lined up to get their cholesterol checked and have purged their refrigerators of fatty foods. Food manufacturers are pumping up sales simply by touting their products as "cholesterol free." Rarely has a health campaign so quickly become a national obsession.

But now a backlash may be in the offing. In the provocative new book Heart Failure, excerpted in the September issue of the Atlantic magazine, Thomas Moore, a Washington-based writer, contends that overzealous crusaders against cholesterol have exaggerated the benefits of low-fat diets. Moore, who spent four years reviewing the scientific literature on the subject, acknowledges that researchers have established a link between high cholesterol and increased risk of heart disease. He argues, however, that diet modification cannot do much to lower cholesterol, that reducing blood levels of the suspect substance has not been proved to prolong life and that cholesterol-lowering drugs may carry more risks than benefits. Moore's readers are likely to come away totally bewildered about what to believe and whose advice to follow.

Is he right? Up to a point, yes. Many of his criticisms of the anticholesterol campaign have been voiced by respected researchers in the New England Journal of Medicine and the Journal of the American Medical Association. Certainly, many people have an overly simplistic view of the relationship between diet and heart disease. Observes Dr. Allan Brett, an assistant professor at the Harvard Medical School: "Some patients have been led to believe that lowering cholesterol is like magic: eat a bowl of oat bran, and you're cured. For most, that's not true."

None of Moore's arguments, however, disprove the basic contention that high- cholesterol diets are potentially hazardous. The evidence against cholesterol is stronger than he implies. If his readers go back to pouring on the gravy and spreading the butter, then the book will have done them a disservice.

Unfortunately, heart disease is a hideously complex phenomenon. Diet is just one of a panoply of risk factors, which also include heredity, smoking, high blood pressure and obesity. Even the idea that cholesterol is "bad" is seriously flawed, since the chemical is produced naturally in the body and is vital to the functioning of human cells. It is carried in the bloodstream by two types of molecules: low-density lipoproteins (LDL) and high-density lipoproteins (HDL). Too much LDL is harmful because it contributes to the accumulation of fatty deposits that block arteries, but large amounts of HDL are thought to be beneficial because they seem to help clean the blood vessels. Moore correctly points out that many routine cholesterol checks may be misleading, since the tests often do not distinguish between LDL and HDL levels, and those that do may be inaccurate.

Moore's contention that diet has little impact on cholesterol levels is an oversimplification. Some patients respond dramatically to diet therapy, others hardly at all. The author cites studies showing that people who change their eating habits generally lower their cholesterol levels by 5% to 10%. But Dr. James Cleeman, coordinator of the NCEP, maintains that the typical reduction range is more like 10% to 15%.

% Even more controversial is Moore's suspicion that lowering cholesterol does not increase one's odds for a longer life. In the major studies that have probed this issue, people with low cholesterol got heart disease less often than those with high levels. But, as Moore points out, the low-cholesterol people did not live longer on average, because some of them died from other ailments. Whether this was by chance or the result of low cholesterol remains an open question. That puzzling outcome does not overly impress most researchers. They feel that as additional, longer studies are completed, it will be proved that lowering cholesterol can prolong life. In the meantime, it makes sense for people to try to reduce their risk of heart disease and take their chances with other illnesses.

Moore is on firmer ground in sounding an alarm about drug therapy. While the NCEP says cholesterol-lowering drugs should be used only after diet modification fails, many doctors are too quick to reach for the prescription pad. Reason: patients find it easier to take pills than to give up steak and eggs. Yet taking drugs for a lifetime can have unintended and perhaps dangerous side effects. The well-established anticholesterol drugs, including cholestyramine and nicotinic acid, seem to be relatively safe, but they can produce such discomforts as nausea and intestinal pain. Newer drugs, like the heavily promoted lovastatin, may be better tolerated, but their long-term safety and effectiveness have not been established. Moreover, reducing cholesterol too far may carry some risk. Some studies, not yet confirmed, have shown a link between abnormally low cholesterol levels and increased danger of cancer and stroke.

So what is the bottom line? Like it or not, there is no simple way to guarantee a life free of heart disease. Someone may swear off French fries for decades and still be struck down. Someone else may eat eggs every day and live to be 100. But in the game of life, smart players look at the odds. And most health professionals remain convinced that a sensible diet, with only moderate amounts of saturated fats and cholesterol, raises the odds of avoiding a heart attack.