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- HEALTH, Page 108Don't Go Back to ButterThe less-cholesterol campaign is under fire, but not discreditedBy 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.