Personal Health : Making Sense Out of Cholesterol Controversy

For the average American, the controversy surrounding a September Atlantic magazine article that challenges the casting of cholesterol as chief villain in coronary heart disease raises questions over whom to believe and why.

The same people who are eating oat bran by the truckload, downing nonfat milk by the tanker full and sneering at eggs and bacon suddenly may wonder whether these actions will do them any good.

The answer, generally accepted in the medical community: Yes, those things will benefit most people--but the mysteries of genetics make it impossible to determine exactly who and how much.

Anatomy of a Dispute

Further, if one looks to research results for confirmation, it’s easy to see how the dispute developed between magazine writer Thomas J. Moore (who says academics, bureaucrats and drug companies have cooperated in a genteel conspiracy to impose cholesterol-lowering diets and drugs on Americans, even though research is inconclusive, at best) and the medical establishment (which says he misunderstood or misrepresented their results and has little sensitivity to the uncertainties in science).

It’s all in how one chooses to read the numbers.

In sometimes mind-numbing detail, Moore walks readers through statistics illustrating his point: that millions of dollars in studies have failed to show that fat-restricted diets have large effects on patients’ blood cholesterol levels; the effect on overall mortality is even less, he says.

Researchers would agree with those statements but would add that even small effects on blood cholesterol, incidence of heart disease and mortality are worth pursuing as public health policy.

On average, studies show, decreases in blood cholesterol do range from modest to downright small; the number of total deaths in study groups often does not change or even increases slightly.

An article last week in the New England Journal of Medicine gives examples of this and mildly chastises cholesterol researchers for the way they have used numbers to support their case against cholesterol. (The timing of the article so soon after Moore’s was coincidental, journal editors say.)

Lipid Research Findings

A study known as the Lipid Research Clinics trial reported in 1984 that the heart attack rate over a five-year period was 9.8% in a control group and 8.1% in men who took a cholesterol-lowering drug, notes the New England Journal of Medicine article by Dr. Allan S. Brett, of Boston’s New England Deaconess Hospital.

But in characterizing this 1.7 percentage-point difference, cholesterol researchers switch to relative proportions. Comparing the 1.7 to 9.8 and making various statistical adjustments, suddenly they are talking about a 19% drop in fatal and nonfatal heart attacks. “This descriptive language, although technically accurate, may operate subliminally to magnify the effect of the intervention for the reader,” Brett writes.

To Moore, it represents a self-serving use of statistics by physicians and researchers supporting the federal government’s National Cholesterol Education Program. He challenges the way such figures have been used to justify the national program, which has issued guidelines for physicians to intervene with strict diets or drugs in patients’ with cholesterol problems.

But the 19% figure is both useful and valid, said Dr. Daniel Steinberg, a UC San Diego professor who laughingly notes that a scientific journal is about to publish an article he wrote called “The End of the Cholesterol Controversy.”

There are 500,000 fatal heart attacks every year, so even a small percentage effect from lowering blood cholesterol would save many people, Steinberg said. In a letter he wrote last week to the Atlantic, he observed: “If the question is whether 100% of experts agree that the currently recommended (cholesterol treatment) guidelines are right on the mark, the answer is no. If the question is whether 98-plus percent of them agree, the answer is yes. . . . The fact that a handful of skeptics dissociate themselves from the views of the great majority does not necessarily mean they are right.”

Steinberg chaired the national 1984 conference that concluded high blood cholesterol causes coronary heart disease. The group’s findings laid the groundwork for the federal cholesterol program.

Steinberg accused Moore of selectively using studies and statistics to prove his point--the very same charge Moore levels at the cholesterol research community.

The identical nature of charge and countercharge points up an underlying reason for the dispute’s existence: science is made of uncertainty but public policies are cast in terms that imply absolute certainty.

Criticisms of Studies

In large part, Moore’s criticisms of cholesterol studies appear to occur because, taken individually, many of them have ambiguous or inconclusive results that their authors blame on limits in study techniques. He objects to conglomerating research to reach conclusions about cholesterol that no single study would support.

“That’s the way it is on most of these public health issues,” said Michael Goldstein, chairman of the Department of Community Health Sciences at the UCLA School of Public Health. “We don’t have data on a lot of things, and we’re extrapolating and trying to make conclusions.”

The very act of taking a research paper full of qualifications and nuances and turning it into a definitive statement for a policy paper or even a newspaper article can make conclusions appear stronger than they are, he said: “It isn’t so much that the research said something else. What it said was ‘X’ but much less strongly and it had a lot of qualifications attached to it. If you add up all the qualifications, that’s a long list . . . so when you add all these qualifications up you might have what appears to be a misleading view.”

Similarly, a study indicating an average improvement in cholesterol levels or longevity in a group of people doesn’t mean a physician can promise an individual patient the same benefit. Also figuring prominently in the equation are an individual’s genetic susceptibility to heart disease and to changes in eating habits, exercise patterns and life style.

But communicating this uncertainty is no easy matter. Paul Saltman, a UC San Diego biochemist noted for his iconoclastic nutrition advice, contends this communications problem led medical authorities to turn high cholesterol into a simple symbol of poor health: “When I talk to people who are in this business, and I say to them, ‘Why don’t you say that (reducing heart disease) is very difficult and it’s not a simple system?’ They say, ‘People can’t understand all that. It’s too complicated. It’s easier if they do what we say.’ ”

Role of Cholesterol

He advises people confused by the Atlantic fuss to consider cholesterol only in a broad context of facts about its role in human metabolism:

--Cholesterol is essential to every cell in the body, particularly those in the brain and nervous system. The goal is not to eliminate cholesterol from the diet or the bloodstream but to keep its concentration from soaring over the short- or long-term.

--Eighty-five percent of the cholesterol in the bloodstream comes not from outside sources, such as eggs, but is made by the body itself.

--The body’s cholesterol production system in the liver is stimulated by excess calories, which trigger the body to begin storing calories as fat. Overeating increases levels of bloodstream cholesterol. (Individual needs vary but the average woman needs about 1,800 calories daily and the average man about 2,400 calories a day. But yo-yo dieting--the practice of alternatively following, then sharply falling off eating regimens--raises cholesterol to levels higher than would be normal for a given caloric intake; that’s because when dieters quit their regimen after at least a week, their bodies’ fat storing mechanism is in high gear as a result of their diets.)

--Cholesterol accumulates in arteries at microscopic lesions of uncertain origin. But recent studies indicate that the lesions themselves are encouraged by the presence of excess blood cholesterol.

--A low-fat diet minimizing saturated fats and emphasizing carbohydrates, fruits and vegetables makes sense not just because it cuts down on cholesterol, but because it tends to eliminate obesity.

Obesity Problem

“The biggest problem we have in food in America,” Saltman said, “is not that it’s poisoned. It’s not that it’s junk. It’s that we have too much of it, it’s too cheap and it’s too good. The net result is that the biggest national problem is obesity. If we could deal with that we could deal with all the other health problems as well.”

Obesity--when individuals are 20% or more over optimal weight for their age, sex and height--is linked not only to heart disease but to diabetes, stroke, hypertension and cancer.

But Saltman labels as “stupid” the National Cholesterol Education Program’s advice that Americans should limit red meat consumption because it is high in saturated fat, which generally raises cholesterol levels more than other types of fats do. He advises eating sensibly to enjoy life, keeping trim and optimizing genetically linked health limits.

“I don’t eat defensively,” he said. “If I eat oat bran, it’s because I enjoy eating breakfast food. But I eat meat and cheese and fish and I’m not afraid of pizzas and hamburgers. I stay away from fried foods--not because I don’t like them but because they’re rich in calories and I have to watch my calories.”

Goldstein said studies have shown people are aware of information about healthy life styles they should adopt. But that generally doesn’t change their behavior. Consequently, if Americans react to Moore’s article in the Atlantic, it is likely to be as justification for existing eating habits, he suggested.

Indeed, at the Atlantic’s administrative offices in New York, public relations director Jim Long noted a change: “You see people walking down the hall now eating Snickers bars with a smile on their face.”