Good Calories, Bad Calories (11 page)

Two years later, the NIH assembled a Task Force on Arteriosclerosis, and it came to similar conclusions in its four-hundred-page, two-volume report.

The task force agreed that a “definitive test” of Keys’s dietary-fat hypothesis “in the general population is urgently needed.” But these assembled experts also did not believe such a study was practical. They worried about the “formidable” costs—perhaps $1 bil ion—and recommended instead that the NIH

proceed with smal er, wel -control ed studies that might demonstrate that it was possible to lessen the risk of coronary heart disease without necessarily relying on diet to do it.

As a result, the NIH agreed to spend only $250 mil ion on two smal er trials that would stil constitute the largest, most ambitious clinical trials ever attempted. One would test the hypothesis that heart attacks could be prevented by the use of cholesterol-lowering drugs. The other would attempt to prevent heart disease with a combination of cholesterol-lowering diets, smoking-cessation programs, and drugs to reduce blood pressure. Neither of these trials would actual y constitute a test of Keys’s hypothesis or of the benefits of low-fat diets. Moreover, the two trials would take a decade to complete, which was longer than the public, the press, or the government was wil ing to wait.

CREATION OF CONSENSUS

In sciences that are based on supposition and opinion…the object is to command assent, not to master the thing itself.

FRANCIS BACON, Novum Organum, 1620

BY 1977, WHEN THE NOTION THAT dietary fat causes heart disease began its transformation from speculative hypothesis to nutritional dogma, no compel ing new scientific evidence had been published. What had changed was the public attitude toward the subject. Belief in saturated fat and cholesterol as kil ers achieved a kind of critical mass when an anti-fat, anti-meat movement evolved independent of the science.

The roots of this movement can be found in the counterculture of the 1960s, and its moral shift away from the excessive consumption represented by fat-laden foods. The subject of famine in the third world was a constant presence in the news: in China and the Congo in 1960, then Kenya, Brazil, and West Africa—where “Vil agers in Dahomey Crawl to Town to Seek Food,” as a New York Times headline read—fol owed by Somalia, Nepal, South Korea, Java, and India; in 1968, Tanzania, Bechuanaland, and Biafra; then Bangladesh, Ethiopia, and much of sub-Saharan Africa in the early 1970s.

Within a decade, the Stanford University biologist Paul Ehrlich predicted in his 1968 best-sel er, The Population Bomb, “hundreds of mil ions of people are going to starve to death in spite of any crash programs embarked upon now.”

The fundamental problem was an ever-increasing world population, but secondary blame fel to an imbalance between food production and consumption. This, in turn, implicated the eating habits in the richer nations, particularly the United States. The “enormous appetite for animal products has forced the conversion (at a very poor rate) of more and more grain, soybean and even fish meal into feed for cattle, hogs and poultry, thus decreasing the amounts of food directly available for direct consumption by the poor,” explained Harvard nutritionist Jean Mayer in 1974. To improve the world situation, insisted Mayer and others, there should be “a shift in consumption in developed countries toward a ‘simplified’ diet containing less animal products and, in particular, less meat.” By doing so, we would free up grain, the “world’s most essential commodity,” to feed the hungry.

This argument was made most memorably in the 1971 best-sel er Diet for a Small Planet, written by a twenty-six-year-old vegetarian named Francis Moore Lappé. The American livestock industry required twenty mil ion tons of soy and vegetable protein to produce two mil ion tons of beef, according to Lappé. The eighteen mil ion tons lost in the process were enough to provide twelve urgently needed grams of protein daily to everyone in the world. This argument transformed meat-eating into a social issue, as wel as a moral one. “A shopper’s decision at the meat counter in Gary, Indiana would affect food availability in Bombay, India,” explained the sociologist Warren Belasco in Appetite for Change, his history of the era.

By the early 1970s, this argument had become intertwined with the medical issues of fat and cholesterol in the diet. “How do you get people to understand that mil ions of Americans have adopted diets that wil make them at best fat, or at worst, dead?” as the activist Jennifer Cross wrote in The Nation in 1974. “That the $139 bil ion food industry has not only encouraged such unwise eating habits in the interest of profit but is so wasteful in many of its operations that we are inadvertently depriving hungry nations of food?” The American Heart Association had taken to recommending that Americans cut back not just on saturated fat but on meat to do so. Saturated fat may have been perceived as the problem, but saturated fat was stil considered to be synonymous with animal fat, and much of the fat in the American diet came from animal foods, particularly red meat.

Ironical y, by 1968, when Paul Ehrlich had declared in The Population Bomb that “the battle to feed al humanity” had already been lost, agricultural researchers led by Norman Borlaug had created high-yield varieties of dwarf wheat that ended the famines in India and Pakistan and averted the predicted mass starvations. In 1970, when the Nobel Foundation awarded its Peace Prize to Borlaug, it justified the decision on the grounds that, “more than any other single person,” Borlaug had “helped to provide bread for a hungry world.”

Other factors were also pushing the public toward a belief in the evils of dietary fat and cholesterol that the medical-research community itself stil considered questionable. The American Heart Association revised its dietary recommendations every two to three years and, with each revision, made its advice to eat less fat increasingly unconditional. By 1970, this prescription applied not just to those high-risk men who had already had heart attacks or had high cholesterol or smoked, but to everyone, “including infants, children, adolescents, pregnant and lactating women, and older persons.” Meanwhile, the press and the public came to view the AHA as the primary source of expert information on the issue.

The AHA had an important al y in the vegetable-oil and margarine manufacturers. As early as 1957, the year Americans first purchased more margarine than butter, Mazola corn oil was being pitched to the public with a “Listen to Your Heart” campaign; the polyunsaturated fats of corn oil would lower cholesterol and so prevent heart attacks, it was said. Corn Products Company, the makers of Mazola, and Standard Brands, producers of Fleischmann’s margarine, both initiated programs to educate doctors to the benefits of polyunsaturated fats, with the implicit assumption that the physicians would pass the news on to their patients. Corn Products Company col aborated directly with the AHA on releasing a “risk handbook” for physicians, and with Pocket Books to publish the revised version, in 1966, of Jeremiah Stamler’s book Your Heart Has Nine Lives. By then, ads for these polyunsaturated oils and margarines needed only to point out that the products were low in saturated fat and low-cholesterol, and this would serve to communicate and reinforce the heart-healthy message.

This al iance between the AHA and the makers of vegetable oils and margarines dissolved in the early 1970s, with reports suggesting that polyunsaturated fats can cause cancer in laboratory animals. This was problematic to Keys’s hypothesis, because the studies that had given some indication that cholesterol-lowering was good for the heart—Seymour Dayton’s VA Hospital trial and the Helsinki Mental Hospital Study—had done so precisely by replacing saturated fats in the diet with polyunsaturated fats. Public-health authorities concerned with our cholesterol dealt with the problem by advising that we simply eat less fat and less saturated fat, even though only two studies had ever tested the effect of such low-fat diets on heart disease, and they had been contradictory.

It’s possible to point to a single day when the controversy was shifted irrevocably in favor of Keys’s hypothesis—Friday, January 14, 1977, when Senator George McGovern announced the publication of the first Dietary Goals for the United States. The document was “the first comprehensive statement by any branch of the Federal Government on risk factors in the American diet,” said McGovern.

This was the first time that any government institution (as opposed to private groups like the AHA) had told Americans they could improve their health by eating less fat. In so doing, Dietary Goals sparked a chain reaction of dietary advice from government agencies and the press that reverberates stil , and the document itself became gospel. It is hard to overstate its impact. Dietary Goals took a grab bag of ambiguous studies and speculation, acknowledged that the claims were scientifical y contentious, and then official y bestowed on one interpretation the aura of established fact. “Premature or not,” as Jane Brody of the New York Times wrote in 1981, “the Dietary Goals are beginning to reshape the nutritional philosophy of America, if not yet the eating habits of most Americans.”

The document was the product of McGovern’s Senate Select Committee on Nutrition and Human Needs, a bipartisan nonlegislative committee that had been formed in 1968 with a mandate to wipe out malnutrition in America. Over the next five years, McGovern and his col eagues—among them, many of the most prominent politicians in the country, including Ted Kennedy, Charles Percy, Bob Dole, and Hubert Humphrey—instituted a series of landmark federal food-assistance programs. Buoyed by their success fighting malnutrition, the committee members turned to the link between diet and chronic disease.

The operative force at work, however, was the committee staff, composed of lawyers and ex-journalists. “We real y were total y naïve,” said the staff director Marshal Matz, “a bunch of kids, who just thought, Hel , we should say something on this subject before we go out of business.”*13 McGovern had attended Nathan Pritikin’s four-week diet-and-exercise program at Pritikin’s Longevity Research Institute in Santa Barbara, California. He said that he lasted only a few days on Pritikin’s very low-fat diet, but that Pritikin’s philosophy, an extreme version of the AHA’s, had profoundly influenced his thinking.

McGovern’s staff were virtual y unaware of the existence of any scientific controversy. They knew that the AHA advocated low-fat diets, and that the dairy, meat, and egg industries had been fighting back. Matz and his fel ow staff members described their level of familiarity with the subject as that of interested laymen who read the newspapers. They believed that the relevant nutritional and social issues were simple and obvious. Moreover, they wanted to make a difference, none more so than Nick Mottern, who would draft the Dietary Goals almost single-handedly. A former labor reporter, Mottern was working as a researcher for a consumer-products newsletter in 1974 when he watched a television documentary about famine in Africa, decided to do something meaningful with his life, and was hired to fil a vacant writing job on McGovern’s committee.

In July 1976, McGovern’s committee listened to two days of testimony on “Diet and Kil er Diseases.” Mottern then spent three months researching the subject and two months writing. The most compel ing evidence, Mottern believed, was the changing-American-diet story, and this became the underlying foundation of the committee’s recommendations: we should readjust our national diet to match that of the turn of the century, at least as the Department of Agriculture had guessed it to be. The less controversial recommendations of the Dietary Goals included eating less sugar and salt, and more fruits, vegetables, and whole grains.

Fat and cholesterol would be the contentious points. Here Mottern avoided the inherent ambiguities of the evidence by relying for his expertise almost exclusively on a single Harvard nutritionist, Mark Hegsted, who by his own admission was an extremist on the dietary-fat issue. Hegsted had studied the effect of fat on cholesterol levels in the early 1960s, first with animals and then, like Keys, with schizophrenic patients at a mental hospital. Hegsted had come to believe unconditional y that eating less fat would prevent heart disease, although he was aware that this conviction was not shared by other investigators working in the field. With Hegsted as his guide, Mottern perceived the dietary-fat controversy as analogous to the specious industry-sponsored “controversy” over cigarettes and lung cancer, and he equated his Dietary Goals to the surgeon general’s legendary 1964 report on smoking and health. To Mottern, the food industry was no different from the tobacco industry in its wil ingness to suppress scientific truth in the interests of greater profits. He believed that those scientists who lobbied actively against dietary fat, like Hegsted, Keys, and Stamler, were heroes.

Dietary Goals was couched as a plan for the nation, but these goals obviously pertained to individual diets as wel . Goal number one was to raise the consumption of carbohydrates until they constituted 55–60 percent of the calories consumed. Goal number two was to decrease fat consumption from approximately 40 percent, then the national average, to 30 percent of al calories, of which no more than a third should come from saturated fats. The report acknowledged that no evidence existed to suggest that reducing the total fat content of the diet would lower blood-cholesterol levels, but it justified its recommendation on the basis that, the lower the percentage of dense fat calories in the diet, the less likely people would be to gain weight,*14 and because other health associations—most notably the American Heart Association—were recommending 30 percent fat in diets. To achieve this low-fat goal, according to the Dietary Goals, Americans would have to eat considerably less meat and dairy products.

Though the Dietary Goals admitted the existence of a scientific controversy, it also insisted that Americans had nothing to lose by fol owing the advice.

“The question to be asked is not why should we change our diet but why not?” explained Hegsted at a press conference to announce publication of the document. “There are [no risks] that can be identified and important benefits can be expected.” But this was stil a hugely debatable position among researchers. After the press conference, as Hegsted recal ed, “al hel broke loose…. Practical y nobody was in favor of the McGovern recommendations.”