The Truth About Fats/ Articles
|by Mary Enig, PhD, and Sally Fallon
In 1954 a young researcher from Russia named David Kritchevsky published a paper describing the effects of feeding cholesterol to rabbits.1 Cholesterol added to vegetarian rabbit chow caused the formation of atheromas—plaques that block arteries and contribute to heart disease. Cholesterol is a heavy weight molecule—an alcohol or a sterol—found only in animal foods such as meat, fish, cheese, eggs and butter. In the same year, according to the American Oil Chemists Society, Kritchevsky published a paper describing the beneficial effects of polyunsaturated fatty acids for lowering cholesterol levels.2 Polyunsaturated fatty acids are the kind of fats found in large amounts in highly liquid vegetable oils made from corn, soybeans, safflower seeds and sunflower seeds. (Monounsaturated fatty acids are found in large amounts in olive oil, palm oil and lard; saturated fatty acids are found in large amounts in fats and oils that are solid at room temperature, such as butter, tallows and coconut oil.)
Rise of Coronary Heart Disease in the 20th Century
Scientists of the period were grappling with a new threat to public health—a steep rise in heart disease. While turn-of-the-century mortality statistics are unreliable, they consistently indicate that heart disease caused no more than ten percent of all deaths, considerably less than infectious diseases such as pneumonia and tuberculosis. By 1950, coronary heart disease, or CHD, was the leading source of mortality in the United States, causing more than 30% of all deaths. The greatest increase came under the rubric of myocardial infarction (MI)—a massive blood clot leading to obstruction of a coronary artery and consequent death to the heart muscle. MI was almost nonexistent in 1910 and caused no more than three thousand deaths per year in 1930. By 1960, there were at least 500,000 MI deaths per year in the US. What life-style changes had caused this increase?
One change was a decrease in infectious disease, following the decline of the horse as a means of transport, the installation of more sanitary water supplies and the advent of better housing, all of which allowed more people to reach adulthood and the heart attack age. The other was a dietary change. Since the early part of the century, when the Department of Agriculture had begun to keep track of food “disappearance” data—the amount of various foods going into the food supply—a number of researchers had noticed a change in the kind of fats Americans were eating. Butter consumption was declining while the use of vegetable oils, especially oils that had been hardened to resemble butter by a process called hydrogenation, was increasing—dramatically increasing. By 1950 butter consumption had dropped from eighteen pounds per person per year to just over ten. Margarine filled in the gap, rising from about two pounds per person at the turn of the century to about eight. Consumption of vegetable shortening—used in crackers and baked goods—remained relatively steady at about twelve pounds per person per year but vegetable oil consumption had more than tripled—from just under three pounds per person per year to more than ten.3
The statistics pointed to one obvious conclusion—Americans should eat the traditional foods that nourished their ancestors, including meat, eggs, butter and cheese, and avoid the newfangled vegetable-oil-based foods that were flooding the grocers’ shelves; but the Kritchevsky articles attracted immediate attention because they lent support to another theory—one that militated against the consumption of meat and dairy products. This was the lipid hypothesis, namely that saturated fat and cholesterol from animal sources raise cholesterol levels in the blood, leading to deposition of cholesterol and fatty material as pathogenic plaques in the arteries. Kritchevsky’s rabbit trials were actually a repeat of studies carried out four decades earlier in St. Petersburg, in which rabbits fed saturated fats and cholesterol developed fatty deposits in their skin and other tissues—and in their arteries. By showing that feeding polyunsaturated oils from vegetable sources lowered serum cholesterol in humans, at least temporarily, Kritchevsky appeared to show that animals findings were relevant to the CHD problem, that the lipid hypothesis was a valid explanation for the new epidemic and that by reducing animal products in the diet Americans could avoid heart disease.
The "evidence" for the lipid hypothesis
In the years that followed, a number of population studies demonstrated that the animal model—especially one derived from vegetarian animals—was not a valid approach for the problem of heart disease in human omnivores. A much publicized 1955 report on artery plaques in soldiers killed during the Korean War showed high levels of atherosclerosis, but another report—one that did not make it to the front pages—found that Japanese natives had almost as much pathogenic plaque—65% versus 75%—even though the Japanese diet at the time was lower in animal products and fat.4 A 1957 study of the largely vegetarian Bantu found that they had as much atheroma—occlusions or plaque buildup in the arteries—as other races from South Africa who ate more meat.5 A 1958 report noted that Jamaican Blacks showed a degree of atherosclerosis comparable to that found in the United States, although they suffered from lower rates of heart disease.6 A 1960 report noted that the severity of atherosclerotic lesions in Japan approached that of the United States.7 The 1968 International Atherosclerosis Project, in which over 22,000 corpses in 14 nations were cut open and examined for plaques in the arteries, showed the same degree of atheroma in all parts of the world—in populations that consumed large amounts of fatty animal products and those that were largely vegetarian, and in populations that suffered from a great deal of heart disease and in populations that had very little or none at all.8 All of these studies pointed to the fact that the thickening of the arterial walls is a natural, unavoidable process. The lipid hypothesis did not hold up to these population studies, nor did it explain the tendency to fatal clots that caused myocardial infarction.
In 1956, an American Heart Association (AHA) fund-raiser aired on all three major networks. The MC interviewed, among others, Irving Page and Jeremiah Stamler of the AHA, and researcher Ancel Keys. Panelists presented the lipid hypothesis as the cause of the heart disease epidemic and launched the Prudent Diet, one in which corn oil, margarine, chicken and cold cereal replaced butter, lard, beef and eggs. But the television campaign was not an unqualified success because one of the panelists, Dr. Dudley White, disputed his colleagues at the AHA. Dr. White noted that heart disease in the form of myocardial infarction was nonexistent in 1900 when egg consumption was three times what it was in 1956 and when corn oil was unavailable. When pressed to support the Prudent Diet, Dr. White replied: “See here, I began my practice as a cardiologist in 1921 and I never saw an MI patent until 1928. Back in the MI free days before 1920, the fats were butter and lard and I think that we would all benefit from the kind of diet that we had at a time when no one had ever heard the word corn oil.”
But the lipid hypothesis had already gained enough momentum to keep it rolling, in spite of Dr. White’s nationally televised plea for common sense in matters of diet and in spite of the contradictory studies that were showing up in the scientific literature. In 1957, Dr. Norman Jolliffe, Director of the Nutrition Bureau of the New York Health Department initiated the Anti-Coronary Club, in which a group of businessmen, ranging in age from 40 to 59 years, were placed on the Prudent Diet. Club members used corn oil and margarine instead of butter, cold breakfast cereals instead of eggs and chicken and fish instead of beef. Anti-Coronary Club members were to be compared with a “matched” group of the same age who ate eggs for breakfast and had meat three times a day. Jolliffe, an overweight diabetic confined to a wheel chair, was confident that the Prudent Diet would save lives, including his own.
In the same year, the food industry initiated advertising campaigns that touted the health benefits of their products—low in fat or made with vegetable oils. A typical ad read: “Wheaties may help you live longer.” Wesson recommended its cooking oil “for your heart’s sake” a Journal of the American Medical Association ad described Wesson oil as a “cholesterol depressant.” Mazola advertisements assured the public that “science finds corn oil important to your health.” Medical journal ads recommended Fleishmann’s unsalted margarine for patients with high blood pressure.
Dr. Frederick Stare, head of Harvard University’s Nutrition Department, encouraged the consumption of corn oil—up to one cup a day—in his syndicated column. In a promotional piece specifically for Procter and Gamble’s Puritan oil, he cited two experiments and one clinical trial as showing that high blood cholesterol is associated with CHD. However, both experiments had nothing to do with CHD, and the clinical trial did not find that reducing blood cholesterol had any effect on CHD events. Later, Dr. William Castelli, Director of the Framingham Study was one of several specialists to endorse Puritan. Dr. Antonio Gotto, Jr., former AHA president, sent a letter promoting Puritan Oil to practicing physicians—printed on Baylor College of Medicine, The De Bakey Heart Center letterhead.9 The irony of Gotto’s letter is that De Bakey, the famous heart surgeon, coauthored a 1964 study involving 1700 patients which also showed no definite correlation between serum cholesterol levels and the nature and extent of coronary artery disease.10 In other words, those with low cholesterol levels were just as likely to have blocked arteries as those with high cholesterol levels. But while studies like De Bakey’s moldered in the basements of university libraries, the vegetable oil campaign took on increased bravado and audacity.
The American Medical Association at first opposed the commercialization of the lipid hypothesis and warned that “the anti-fat, anti-cholesterol fad is not just foolish and futile. . . it also carries some risk.” The American Heart Association, however, was committed. In 1961 the AHA published its first dietary guidelines aimed at the public. The authors, Irving Page, Ancel Keys, Jeremiah Stamler and Frederick Stare, called for the substitution of polyunsaturates for saturated fat, even though Keys, Stare and Page had all previously noted in published papers that the increase in CHD was paralleled by increasing consumption of vegetable oils. In fact, in a 1956 paper, Keys had suggested that the increasing use of hydrogenated vegetable oils might be the underlying cause of the CHD epidemic.11
Stamler shows up again in 1966 as an author of Your Heart Has Nine Lives, a little self-help book advocating the substitution of vegetable oils for butter and other so-called “artery clogging” saturated fats. The book was sponsored by makers of Mazola Corn Oil and Mazola Margarine. Stamler did not believe that lack of evidence should deter Americans from changing their eating habits. The evidence, he stated, “ . . was compelling enough to call for altering some habits even before the final proof is nailed down. . . the definitive proof that middle-aged men who reduce their blood cholesterol will actually have far fewer heart attacks waits upon diet studies now in progress.” His version of the Prudent Diet called for substituting low-fat milk products such as skim milk and low-fat cheeses for cream, butter and whole cheeses, reducing egg consumption and cutting the fat off red meats. Heart disease, he lectured, was a disease of rich countries, striking rich people who ate rich food. . . including “hard” fats like butter.
It was in the same year, 1966, that the results of Dr. Jolliffe’s Anti-Coronary Club experiment were published in the Journal of the American Medical Association.12 Those on the Prudent Diet of corn oil, margarine, fish, chicken and cold cereal had an average serum cholesterol of 220, compared to 250 in the meat-and-potatoes control group. However, the study authors were obliged to note that there were eight deaths from heart disease among Dr. Jolliffe’s Prudent Diet group, and none among those who ate meat three times a day. Dr. Jolliffe was dead by this time. He succumbed in 1961 from a vascular thrombosis, although the obituaries listed the cause of death as complications from diabetes. The “compelling proof” that Stamler and others were sure would vindicate wholesale tampering with American eating habits had not yet been “nailed down.”
The problem, said the insiders promoting the lipid hypothesis, was that the numbers involved in the Anti-Coronary Club experiment were too small. Dr. Irving Page urged a National Diet-Heart Study involving one million men, in which the results of the Prudent Diet could be compared on a large scale with the those on a diet high in meat and fat. With great media attention, the National Heart Lung and Blood Institute organized the stocking of food warehouses in six major cities, where men on the Prudent Diet could get tasty polyunsaturated donuts and other fabricated food items free of charge. But a pilot study involving 2,000 men resulted in exactly the same number of deaths in both the Prudent Diet and the control group. A brief report in Circulation, March 1968, stated that the study was a milestone “in mass environmental experimentation” that would have “an important effect on the food industry and the attitude of the public toward its eating habits.” But the million-man Diet Heart Study was abandoned in utter silence “for reasons of cost.” Its chairman, Dr. Irving Page, died of a heart attack.
Hydrogenation and trans fats
Most animal fats—like butter, lard and tallow—have a large proportion of saturated fatty acids. Saturated fats are straight chains of carbon and hydrogen that pack together easily so that they are relatively solid at room temperature. Oils from seeds are composed mostly of polyunsaturated fatty acids. These molecules have kinks in them at the point of the unsaturated double bonds. They do not pack together easily and therefore tend to be liquid at room temperature. Judging from both food data and turn-of-the-century cookbooks, the American diet in 1900 was a rich one—with at least 35 to 40 percent of calories coming from fats, mostly dairy fats in the form of butter, cream, whole milk and eggs. Salad dressing recipes usually called for egg yolks or cream; only occasionally for olive oil. Lard or tallow served for frying; rich dishes like head cheese and scrapple contributed additional saturated fats during an era when cancer and heart disease were rare. Butter substitutes made up only a small portion of the American diet, and these margarines were blended from coconut oil, animal tallow and lard, all rich in natural saturates.
The technology by which liquid vegetable oils could be hardened to make margarine was first discovered by a French chemist named Sabatier. He found that a nickel catalyst would cause the hydrogenation—the addition of hydrogen to unsaturated bonds to make them saturated—of ethylene gas to ethane. Subsequently the British chemist Norman developed the first application of hydrogenation to food oils and took out a patent. In 1909, Procter & Gamble acquired the US rights to the British patent that made liquid vegetable oils solid at room temperature. The process was used on both cottonseed oil and lard to give “better physical properties”—to create shortenings that did not melt as easily on hot days.
The hydrogenation process transforms unsaturated oils into straight “packable” molecules, by rearranging the hydrogen atoms at the double bonds. In nature, most double bonds occur in the cis configuration, that is with both hydrogen atoms on the same side of the carbon chain at the point of the double bond. It is the cis isomers of fatty acids that have a bend or kink at the double bond, preventing them from packing together easily. Hydrogenation creates trans double bonds by moving one hydrogen atom across to the other side of the carbon chain at the point of the double bond. In effect, the two hydrogen atoms then balance each other and the fatty acid straightens, creating a packable “plastic” fat with a much higher melting temperature. Although trans fatty acids are technically unsaturated, they are configured in such a way that the benefits of unsaturation are lost. The presence of several unpaired electrons presented by contiguous hydrogen atoms in their cis form allows many vital chemical reactions to occur at the site of the double bond. When one hydrogen atom is moved to the other side of the fatty acid molecule during hydrogenation, the ability of living cells to make reactions at the site is compromised or altogether lost. Trans fatty acids are sufficiently similar to natural fats that the body readily incorporates them into the cell membrane; once there their altered chemical structure creates havoc with thousands of necessary chemical reactions—everything from energy provision to prostaglandin production.
After the second world war, “improvements” made it possible to plasticize highly unsaturated oils from corn and soybeans. New catalysts allowed processors to “selectively hydrogenate” the kinds of fatty acids with three double bonds found in soy and canola oils. Called “partial hydrogenation,” the new method allowed processors to replace cottonseed oil with more unsaturated corn and soy bean oils in margarines and shortenings. This spurred a meteoric rise in soybean production, from virtually nothing in 1900 to 70 million tons in 1970, surpassing corn production. Today soy oil dominates the market and is used in almost eighty percent of all hydrogenated oils.
The particular mix of fatty acids in soy oil results in shortenings containing about 40% trans fats, an increase of about 5% over cottonseed oil, and 15% over corn oil. Canola oil, processed from a hybrid form of rape seed, is particularly rich in fatty acids containing three double bonds and the shortening can contain as much as 50% trans fats. Trans fats of a particularly problematical form are also formed during the deodorization of canola oil, although they are not indicated on labels for the liquid oil.12a
Certain forms of trans fatty acids occur naturally in dairy fats. Trans-vaccenic acid makes up about 4% of the fatty acids in butter. It is an interim product which the ruminant animal then converts to conjugated linoleic acid, a highly beneficial anti-carcinogenic component of animal fat. Humans seem to utilize the small amounts of trans-vaccenic acid in butter fat without ill effects.
But most of the trans isomers in modern hydrogenated fats are new to the human physiology and by the early 1970’s a number of researchers had expressed concern about their presence in the American diet, noting that their increasing use had paralleled the increase in both heart disease and cancer. The unstated solution was one that could be easily presented to the public: Eat natural, traditional fats; avoid newfangled foods made from vegetable oils; use butter, not margarine. But medical research and public consciousness took a different tack, one that accelerated the decline of traditional foods like meat, eggs and butter, and fueled continued dramatic increases in vegetable oil consumption.
Shenanigans at the AHA
Although the AHA had committed itself to the lipid hypothesis and the unproven theory that polyunsaturated oils afforded protection against heart disease, concerns about hydrogenated vegetable oils were sufficiently great to warrant the inclusion of the following statement in the organization’s 1968 diet heart statement: “Partial hydrogenation of polyunsaturated fats results in the formation of trans forms which are less effective than cis, cis forms in lowering cholesterol concentrations. It should be noted that many currently available shortening and margarines are partially hydrogenated and may contain little polyunsaturated fat of the natural cis, cis form.” 150,000 copies of the statement were printed but never distributed. The shortening industry objected strongly and a researcher named Fred Mattson of Procter and Gamble convinced Campbell Moses, medical director of the AHA, to remove it.13 The final recommendations for the public contained three major points—restrict calories, substitute polyunsaturates for saturates and reduce cholesterol in the diet.
Other organizations fell in behind the AHA in pushing vegetable oils instead of animal fats. By the early 1970’s the National Heart Lung and Blood Institute, the AMA, the American Dietetic Association and the National Academy of Science had all endorsed the lipid hypotheses and the avoidance of animal fats for those Americans in the “at risk” category.
Since Kritchevsky’s early studies, many other trials had shown that serum cholesterol can be lowered by increasing ingestion of polyunsaturates. The physiological explanation for this is that when excess polyunsaturates are built into the cell membranes, resulting in reduced structural integrity or “limpness,” cholesterol is sequestered from the blood into the cell membranes to give them “stiffness.” The problem was that there was no proof that lowering serum cholesterol levels could stave off CHD. That did not prevent the American Heart Association from calling for “modified and ordinary foods” useful for the purpose of facilitating dietary changes to newfangled oils and away from traditional fats. These foods, said the AHA literature, should be made available to the consumer, “reasonably priced and easily identified by appropriate labeling. Any existing legal and regulatory barriers to the marketing of such foods should be removed.”
Shenanigans at the FDA
The man who made it possible to remove any “existing legal and regulatory barriers” was Peter Barton Hutt, a food lawyer for the prestigious Washington, DC law firm of Covington and Burling. Hutt once stated that “Food law is the most wonderful field of law that you can possibly enter.” After representing the edible oil industry, he temporarily left his law firm to become the FDA’s general council in 1971. The regulatory barrier to foods useful to the purpose of changing American consumption patterns was the Food, Drug and Cosmetic Act of 1938, which stated that “. . . there are certain traditional foods that everyone knows, such as bread, milk and cheese, and that when consumers buy these foods, they should get the foods that they are expecting. . . [and] if a food resembles a standardized food but does not comply with the standard, that food must be labeled as an ’imitation’”.
The 1938 Food, Drug and Cosmetic Act had been signed into law partly in response to consumer concerns about the adulteration of ordinary foodstuffs. Chief among the products with a tradition of suffering competition from imitation products were fats and oils. In Life on the Mississippi, Mark Twain reports on a conversation overheard between a New Orleans cottonseed oil purveyor and a Cincinnati margarine drummer. New Orleans boasts of selling deodorized cottonseed oil as olive oil in bottles with European labels. “We turn out the whole thing—clean from the word go—in our factory in New Orleans. . . We are doing a ripping trade, too.” The man from Cincinnati reports that his factories are turning out oleomargarine by the thousands of tons, an imitation that “you can’t tell from butter.” He gloats at the thought of market domination. “You are going to see the day, pretty soon, when you won’t find an ounce of butter to bless yourself with, in any hotel in the Mississippi and Ohio Valleys, outside of the biggest cities. . . And we can sell it so dirt cheap that the whole country has got to take it. . . butter don’t stand any show—there ain’t any chance for competition. Butter’s had its day—and from this out, butter goes to the wall. There’s more money in oleomargarine than, why, you can’t imagine the business we do.”
In the tradition of Mark Twain’s riverboat hucksters, Peter Barton Hutt guided the FDA through the legal and congressional hoops to the establishment of the FDA “Imitation” policy in 1973, which attempted to provide for “advances in food technology” and give “manufacturers relief from the dilemma of either complying with an outdated standard or having to label their new products as ‘imitation’ . . . [since ]. . . such products are not necessarily inferior to the traditional foods for which they may be substituted.” Hutt considered the word “imitation” to be over simplified and inaccurate—“potentially misleading to consumers.” The new regulations defined “inferiority” as any reduction in content of an essential nutrient that is present at a level of two percent or more of the US Recommended Daily Allowance (RDA). The new imitation policy meant that imitation sour cream, made with vegetable oil and fillers like guar gum and carrageenan, need not be labelled imitation as long as artificial vitamins were added to bring macro nutrient levels up to the same amounts as those in real sour cream. Coffee creamers, imitation egg mixes, processed cheeses and imitation whipped cream no longer required the imitation label, but could be sold as real and beneficial foods, low in cholesterol and rich in polyunsaturates.
These new regulations were adopted without the consent of Congress, continuing the trend instituted under Nixon in which the White House would use the FDA to promote certain social agendas through government food policies. They had the effect of increasing the lobbying clout of special interest groups, such as the edible oil industry, and short circuiting public participation in the regulatory process. They allowed food processing innovations regarded as “technological improvements” by manufacturers to enter the market place without the onus of economic fraud that might be engendered by greater consumer awareness and congressional supervision. They ushered in the era of ersatz foodstuffs, convenient counterfeit products—weary, stale, flat and immensely profitable.
Shenanigans in Congress
Congress did not voice any objection to this usurpation of its powers, but entered the contest on the side of the lipid hypothesis. The Senate Select Committee on Nutrition and Human Needs, chaired by George McGovern during the years 1973 to 1977, actively promoted the use of vegetable oils. “Dietary Goals for the United States,” published by the committee, cited U.S. Department of Agriculture data on fat consumption, and stated categorically that “the overconsumption of fat, generally, and saturated fat in particular. . . have been related to six of the ten leading causes of death. . .” in the United States. The report urged the American populace to reduce overall fat intake and to substitute polyunsaturates for saturated fat from animal sources—margarine and corn oil for butter, lard and tallow. Opposing testimony included a moving letter—buried in the voluminous report—by Dr. Fred Kummerow of the University of Illinois, urging a return to traditional whole foods and warning against the use of soft drinks. In the early 1970’s, Kummerow had shown that trans fatty acids caused increased rates of heart disease in pigs. A private endowment allowed him to continue his research—government funding agencies such as National Institutes of Health refused to give him further grants.
One unpublished study that was known to McGovern Committee members but not mentioned in its final report compared calves fed saturated fat from tallow and lard with those fed unsaturated fat from soybean oil. The calves fed tallow and lard did indeed show higher plasma cholesterol levels than the soybean oil-fed calves, and fat streaking was found in their aortas. Atherosclerosis was also enhanced. But the calves fed soybean oil showed a decline in calcium and magnesium levels in the blood, possibly due to inefficient absorption. They utilized vitamins and minerals inefficiently, showed poor growth, poor bone development and had abnormal hearts. More cholesterol per unit of dry matter was found in the aorta, liver, muscle, fat and coronary arteries, a finding which led the investigators to the conclusion the lower blood cholesterol levels in the soybean-oil fed calves may have been the result of cholesterol being transferred from the blood to other tissues. The calves in the soybean oil group also collapsed when they were forced to move around and they were unaware of their surroundings for short periods. They also had rickets and diarrhea.
The McGovern Committee report continued dietary trends already in progress—the increased use of vegetables oils, especially in the form of partially hydrogenated margarines and shortenings. In 1976, the FDA established GRAS (Generally Recognized as Safe) status for hydrogenated soybean oil. A report prepared by the Life Sciences Research Office of the Federation of American Scientists for Experimental Biology (LSRO-FASEB) concluded that “There is no evidence in the available information on hydrogenated soybean oil that demonstrates or suggests reasonable ground to suspect a hazard to the public when it is used as a direct or indirect food ingredient at levels that are now current or that might reasonably be expected in the future.”
Part 1, 2, 3, 4, References