Brain and Mouth Disease
Lionel Tiger
© New York Press, April 18, 2001
In 1992 I published a book called the Pursuit of Pleasure in which I argued that there were evolution-based reasons for seeking out what provided pleasure. Included of course was food. In addition I suggested that the wine with which it is often if not usually associated might also when consumed in moderation have moderate but real health benefits over and above the tastiness and convivial buzz it provided.
Needless to say this was a popular assertion among people in the wine industry. One result was that I asked to convey this glad message at a meeting at the National Press Club in Washington to advocate the so-called Mediterranean Diet in conjunction with sensible consumption of wine – which is usually a traditional part of that diet.
The person describing the health benefits of the Mediterranean Diet was Dimitrios Trichopoulos, Professor of epidemiology and public health at Harvard University. When we completed our respective talks we shared a cab to Washington’s National Airport en route back to our home bases. On the way I asked Dr Trichopoulos "If I faithfully follow the Mediterranean Diet, how much longer will I live?" He seemed taken aback by the remark and said something like "That’s a very interesting question. Perhaps we should put a graduate student on the problem."
I don’t know if he ever did. But a lengthy article by Gary Taubes in the March 30 issue of SCIENCE, the premier American scientific publication, suggests that the answer to my question "How much longer will I live?" is - not much. And if the analysis is correct, it will have an explosive impact on the vast industry in this country and in fact the world which is based on the notion that fat is bad and that consuming it will kill you. But as Taubes points out, 50 years of mainstream nutritional research and hundreds of millions of research dollars have not proved that if you eat a low-fat diet you will live longer. Certainly your cholesterol levels will be lower. But the link between diet and longevity it has been argued remains undemonstrated.
Of course the individual steps are well-known of what happens in your body when you have cheese or a steak. Your cholesterol levels will elevate. This increases the likelihood that the cholesterol will congeal and attach itself to your arteries and hence clog them – a malady called atherosclerosis. In turn this will increase the risk of coronary heart disease and heart attacks which will diminish your expectancy of life. This is now the utterly accepted medical and nutritional orthodoxy. It has gripped the society in practice and symbolically, in a form of brain-and-mouth disease. Countless people are embarked on more or less strict diets in which consumption of a tablespoon of olive oil or pat of butter or hunk of lamb chop are the sign not only a kind of moral depravity but also a reckless disregard for personal survival. Fat has become the Devil’s weapon. And people who pursue a monogamous relationship with low-fat carbs and steamed vegetables will regard a date with a steak as equivalent to an act of flamboyant multi-partner adultery.
However while the individual steps of the effect of fat have been demonstrated, the whole chain of events and their impact has not been. Among people not already at risk for heart disease, for example enthusiastic smokers with high blood pressure, according to Taubes and the research of which he is the accountant, the evidence is weak that sharply reduced consumption of saturated fats will increase longevity more than a few weeks, perhaps as much as three months. As long ago as 1969, the National Heart Institute stated plainly "It is not known whether dietary manipulation has any effect whatsoever on coronary heart disease." In fact, the authors of the report in which this was the conclusive sentence were concerned that because fat is so important to cell membranes and the brain (which is 70% fat) that too little fat could be a more serious medical deficit than too much. There is some evidence that very low cholesterol levels are associated with increased risk for auto accidents and aggressive interaction. Japanese physicians have found that low levels were associated with hemorrhagic stroke and may counsel their patients to raise their levels.
Since the beginning of the 70's Americans have dropped their consumption of fat to about 34% of their calories from fat, down from over 40% beforehand. The incidence of heart disease does not seem to have declined, as a 10-year study reported in the New England Journal of Medicine in 1998. Nonetheless, the treatment of heart disease has improved enormously – with more than 5.4 million heart-related procedures compared with 1.2 million in l979. This may provide the questionable impression that it is dietary change which is responsible for improved coronary experience.
Furthermore, the replacement of fat-containing foods by carbohydrates may have contributed to an epidemic of obesity and then diabetes among Americans. The term "fat-free" on a product appears to provide permission to consume large portions of it, producing an intake well beyond what appears to be necessary to balance energy consumed and energy used. Taubes describes how the principal political supporter of the low-fat push in the public arena was Senator George McGovern who had himself gone through the severely low-fat Pritikin diet program. McGovern then held two days of committee testimony in l976 on the subject and followed up by commissioning a former labor reporter for the Providence Journal who had no scientific background to produce the first "Dietary Goals for the United States." In 1977 two government agencies took up the fat/death drama but only one, Agriculture, had public impact when it reiterated the McGovern findings though ample contrary evidence was available and ignored. The National Academy of Sciences report on the same subject was far less media-worthy because all it said was that Americans should eat carefully, modestly, and less. But it did not emphasize killer fat as the main meal-time Mephistopheles.
The issue became even more complex when the differences became clearer between HDL – good cholesterol – and the bad – LDL.
Some foods increase both at the same time, and some such as fats like olive oil stimulate the good flavor of cholesterol. Little of this is reflected in current government recommendations about what is good to eat. Taubes provides what is in effect an almost hilarious deconstruction of the nutritional effect of a porterhouse steak. After broiling, the meat is about half fat, half protein. 51% of the fat turns out to be monounsaturated and 90% of that is the kind of benign fat as in olive oil. 45% of the fat is indeed saturated – bad – but one-third of it is stearic acid – neither good or bad. The remaining 4% is polyunsaturated – good. In sum, as much as 70% of porterhouse fat will improve cholesterol levels compared with an alternative dose of bread, rice, pasta, or potatoes.
I’ve argued here before that human beings did not evolve to eat the carbohydrate foods to which peasants had to turn when they could no longer hunt and gather – mainly rice and the grains. A Rutgers graduate student, Matt Sponheimer, published a convincing report in Nature several years ago of his analysis of our ancestral teeth which revealed clear evidence of meat-eating.
But it is important to be prudent about the material I’ve described here – there will undoubtedly be a major controversy about it, as there should be. I remain very wary of uncritical consumption of high-fat meats such as prime beef which may indeed in large quantities be difficult for the evolved human system to process – wild game has about 3% animal fat and prime beef closer to 36%. And it seems to me that the Atkins-type diets which replace carbohydrates with foods such as bacondoublecheeseburgers may well be seriously ill-advised. Nevertheless, humans evolved as omnivores and we seem well-equipped to eat well-balanced and moderate diets of the foods which were in our environment as we evolved – animals, fish, legumes fruits, vegetables, nuts, berries, and honey when we could get it. Ample fruits, vegetables, and nuts may deliver protective impacts and are obviously one sign of the current good gastronomic fortune of North Americans – our temperate climate provides us with a good cross-section of an ideal grocery store. And it would be irresponsible to avoid stressing exercise as a factor in healthy nutrition – we were born to run, for our dinner.
It appears that people who are committed to low-fat diets almost invariably turn to high-carbohydrate regimes, many components of which provide physiological stimuli to increased hunger. Perhaps a dab of fat will do you, to provide a satisfying experience with food and transform it from battle rations into a calmly sensible aspect of the pursuit of pleasure.
© New York Press, April 18, 2001