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Mainely Tipping Points

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Mainely Tipping Points 13: The Failure of the Low-Fat, High-Carbohydrate American Diet

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(Oops!  Read TP 12 first; it’s part of a series in the essays) 

Tipping Points 13

The Failure of the Low-Fat, High-Carbohydrate American Diet

 

 When Luise Light and her team of experts attempted to scientifically formulate the 1980 USDA Food Guide, they accepted two current dietary ideas as truth:  fat should be no more than 30 percent of the diet, and since the end of World War II, and especially in the 1960s, Americans had been experiencing “rising rates of heart disease, high blood pressure, stroke, and diabetes” (13, Luise Light, WHAT TO EAT:  THE TEN THINGS YOU REALLY NEED TO KNOW TO EAT WELL AND BE HEALTHY).

Current historians show us that the low-fat premise that has governed the American diet for the past fifty years sprang from belief, not science, and became part of American cultural and economic practices when the stars aligned around a constellation that included the political power of a congressional committee, media acceptance of its recommendations, and the firmly-held beliefs of a handful of people.

Science writer Gary Taubes, in his myth-exploding article “The Soft Science of Dietary Fat,” published in “Science” magazine in March 2001, questioned the idea that there ever was an epidemic of heart disease after World War II (http://www.nasw.org/awards/2001/The%20soft%20science.pdf).  When Taubes interviewed Harry Rosenberg, Director of the National Center for Health Statistics (NCHS), Rosenberg said a heart disease epidemic never existed.  First, in 1949 the International Classification of Diseases (ICD) added arteriosclerotic heart disease as a new category under the general category of heart diseases.  Between 1948-1949, the new category appeared to raise coronary disease death rates about 20 percent for males and 35 percent for females. 

Again, In 1965, the ICD added a category for coronary heart disease, which added more deaths to the statistical data as physicians began using the new categories.  Furthermore, Rosenberg explained, by the 1950s, Americans were healthier, so more were living to be 50-year-olds who would go on to die of chronic diseases like heart disease, which physicians were now listing on death certificates under the new categories.  Taubes reports that Rosenberg said that, in actuality, risk rates of dying from a heart attack remained unchanged.

Taubes also discussed the fact that between 1989 and 1992, three independent research groups (Harvard Medical School; The University of California, San Francisco, funded by the U.S. Surgeon General’s Office; and McGill University, Montreal) used computer models to work out added life expectancy for a person eating a low-fat diet that controlled saturated fats.  All three models agreed, but their conclusions have been ignored by media. 

The Harvard study showed that if a person’s total fat consumption was less than 30 percent of their daily total calories and if their saturated fat consumption was 10 percent of that 30 percent, a healthy nonsmoker might add from 3 days to 3 months of life.  The latter two studies showed net increase of life expectancy would be from three to four months.  Taubes noted that the U.S. Surgeon General’s office tried to prevent the University of California study from being published in “The Journal of the American Medical Association (JAMA), but JAMA published it in June 1991.

The Lipid Hypothesis is the “scientific” paradigm calling for a low-fat diet.  The Lipid Hypothesis is the premise that ingested fat, especially saturated fat, raises blood cholesterol levels, and high cholesterol levels cause chronic heart disease (CHD).  Yet, many, many scientists now have argued that these cause-and-effect links have never been proven and, in fact, cannot be proven.  More recently than Taubes, Michael Pollan, in IN DEFENSE OF FOOD (2008), traces this history and current thinking on dietary fats in a section entitled “The Melting of the Lipid Hypothesis” (40-50). 

So how did the Lipid Hypothesis and the low-fat paradigm get installed with scant scientific data to support it?  Biochemist Ancel Keys is a key player.  In the mid 1950s, Keys (University of Minnesota) claimed that his epidemiological Seven Countries Study showed a correlation between the consumption of dietary fat and heart disease.  But, an epidemiological study cannot control or eliminate variables, and correlation is not proved causation.  Furthermore, many now, among them Taubes and Uffe Ravnskov, claim that Keys eliminated countries whose statistics did not fit his hypotheses, like France, Holland, Switzerland, Norway, Denmark, Sweden, and West Germany, where national populations ate 30 to 40 percent of their calories as fat and whose death rates from CHD were half that of the United States.  Nevertheless, in 1961, the American Heart Association began advocating low-fat diets for men with high cholesterol levels.

Also in the 1950s, Nathan Pritkin, was diagnosed with heart disease.  Though he had no college degree and no scientific training, Pritkin created and published a low-fat, aerobic exercise regime that sold millions of copies.  Pritkin also suffered from leukemia, and it began causing complications and pain in the early 1980s.  Pritkin committed suicide in 1985.        

In 1977, the Congressional Select Committee on Nutrition and Human Needs, chaired by Senator George McGovern, promoted the low-fat hypothesis—despite objections by scientists expert in the field.  Taubes determines that “a handful of McGovern staffers…almost single-handedly changed nutritional policy in this country” by initiating “the process of turning the dietary fat hypothesis into dogma” (4).

In 1976, Taubes reports, after two days of testimony, this committee turned “the task of researching and writing the first `Dietary Goals for the United States’” over to Nick Mottern, a labor reporter with “no experience writing about science, nutrition, or health” (5).  Mottern relied on Harvard School of Public Health nutritionist Mark Hegsted’s low-fat beliefs.  Hegsted, unlike E. H. Ahrens, whose laboratory at the Rockefeller University in New York City was doing seminal research on fat and cholesterol metabolism, saw no risks associated with such a major change to the American diet.  Ahrens, as early as 1969, was concerned that eating less fat or changing the proportions of saturated to unsaturated fats could have profound and harmful effects on the body (3-6).  Nevertheless, the Select Committee published Mottern’s dietary guidelines. 

Next, Taube relates, Carol Tucker Foreman, a political appointee at USDA who later forms a public relations and lobbying firm whose clients have included Phillip Morris, Monsanto (bovine growth hormone), and Procter and Gamble (fake fat Olestra), hired Hegsted to produce “Using the Dietary Guidelines for Americans,” which supported the McGovern Committee Report.  Foreman hired Hegsted despite the fact that Philip Handler, National Academy of Sciences (NAS) President and an expert on metabolism, had told her that Mottern’s Dietary Goals were “`nonsense’ “ (6).

When NAS released its own dietary guidelines a few months later (watch your weight and everything else will be all right), the media criticized the NAS for having industry connections.  Hegsted later returned to Harvard where his research was funded by Frito-Lay.

So, a consensus was achieved, oneTaube says is “continuously reinforced by physicians, nutritionists, journalists, health organizations, and consumer advocacy groups such as the Center for Science in the Public Interest” (1).  And, science was “left to catch up” (7).

 Only, science never has.  And, what has emerged is that all calories are not equal and substituting carbohydrates for fat has caused weight gain and diabetes.  And, according to lipid biochemist Mary Enig, substituting highly-processed fats for time-honored, traditional fats is causing chronic heart disease.   

Pollan notes that in a 2001 review of the relevant research and report by “prominent nutrition scientists” at the Harvard School of Public Health, “just about every strut supporting the theory that dietary fat causes heart disease” was removed, except for consuming trans fats and consuming fats that alter ratios of omega 3 to omega 6 fatty acids (41-42).  Pollan notes the Harvard scientists stated the following in their report’s second paragraph:  “`It is now increasingly recognized that the low-fat campaign has been based on little scientific evidence and may have caused unintended health consequences’ “ (43).    

Pollan assesses that the low-fat ideology of nutritionism has been nutrition’s “supreme test and, as now is coming clear, its most abject failure” (41).