Brain-and-Mouth Disease: Nonsense About Low-Fat Diets

Written by Lionel Tiger on . Posted in Breaking News, Posts.


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 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 was 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 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, that is based on the
notion that fat is bad and that consuming it will kill you.

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 remains undemonstrated.

The
individual steps of what happens in your body when you have cheese or a steak
are well known. 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 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 lambchop is the sign
not only of 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 (like 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 percent fat),
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 70s Americans have dropped their consumption of fat to about
34 percent of their calories, down from more than 40 percent beforehand. The incidence
of heart disease does not seem to have declined, according to 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 1979. This may provide the
questionable impression that it is dietary change that 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 seems 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 Sen. George McGovern, who had himself gone through
the severely low-fat Pritikin diet program. McGovern then held two days of committee
testimony in 1976 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 mealtime 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. Some 51 percent of the fat turns out to be monounsaturated,
and 90 percent of that is the kind of benign fat, as in olive oil. Some 45 percent
of the fat is indeed saturated–bad–but one-third of that is stearic
acid–neither good or bad. The remaining 4 percent is polyunsaturated–good.
In sum, as much as 70 percent 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 Science several years ago on 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 percent animal fat, and prime beef closer to 36 percent).
And it seems to me that the Atkins-type diets that replace carbohydrates with
foods such as bacondoublecheeseburgers may be seriously ill-advised.

Nevertheless,
humans evolved as omnivores, and we seem well-equipped to eat well-balanced and
moderate diets of the foods that 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.

 

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