Thursday, May 10, 2007


I originally put the post below up around 18 months ago. Seeing that the cholesterol juggernaut (See one small instance here) still seems to be rolling on like an unsinkable Titanic (sorry about the mixed metaphor), I think I need to repeat it:

"If you eat too much cholesterol, or saturated fat, your blood cholesterol will rise to dangerous levels. Excess cholesterol will then seep through your artery walls causing thickenings (plaques), which will eventually block blood flow in vital arteries, resulting in heart attacks and strokes.... Scientific hypotheses don't get much simpler than this: the cholesterol, or diet-heart, hypothesis, which has broken free from the ivory towers of academia to impact with massive force on society. It has driven a widespread change in the type of food we are told to eat, and consequently the food that lines the supermarket shelves. Many people view bacon and eggs as a dangerous killer, butter is shunned, and a multi-billion pound industry has sprung up providing 'healthy' low-fat alternatives.

However, all is not what it seems. The cholesterol hypothesis can be likened to a cathedral built on a bog. Rather than admit they made a horrible mistake and let it sink, the builders decided to try and keep the cathedral afloat at all costs. Each time a crack appeared, a new buttress was built. Then further buttresses were built to support the original buttresses. Although direct contradictions to the cholesterol hypothesis repeatedly appear, nobody dares to say 'okay, this isn't working, time to build again from scratch'. That decision has become just too painful, especially now that massive industries, Nobel prizes, and glittering scientific careers, have grown on the back of the cholesterol hypothesis. The statin market alone is worth more than 20 billion pounds each year.

In reality, cracks in the hypothesis appeared right from the very start. The first of these was the stark observation that cholesterol in the diet has no effect on cholesterol levels in the bloodstream: 'There's no connection whatsoever between cholesterol in food and cholesterol in blood. And we've known that all along. Cholesterol in the diet doesn't matter at all unless you happen to be a chicken or a rabbit.' Ancel Keys PhD, professor emeritus at the University of Minnesota 1997.

A bit of a blow to a cholesterol hypothesis, you might think, to find that dietary cholesterol has no effect on blood cholesterol levels. However, as everyone was by then fully convinced that something rich and 'fatty' in the diet was the primary cause of heart disease, nobody was willing to let go.

So the hypothesis quietly altered, from cholesterol in the diet to saturated fat in the diet - or a bit of both. As if cholesterol and saturated fat are similar things. In reality, this could hardly be further from the truth. Saturated fat and cholesterol have completely different functions in the body, and they have very different chemical structures....

It is true that Ancel Keys appeared to have proven the link between saturated fat consumption and heart disease, but when it came to the major interventional trials, confirmation proved elusive. The MR-FIT trial in the USA was the most determined effort to prove the case. This was a massive study in which over 350,000 men at high risk of heart disease were recruited. In one set of participants, cholesterol consumption was cut by 42 percent, saturated fat consumption by 28 percent and total calories by 21 percent. This should have made a noticeable dent in heart disease rates.

But nothing happened. The originators of the MR-FIT trials refer to the results as 'disappointing', and say in their conclusions: 'The overall results do not show a beneficial effect on Coronary Heart Disease or total mortality from this multifactor intervention.'

In fact, no clinical trial on reducing saturated fat intake has ever shown a reduction in heart disease. Some have shown the exact opposite: 'As multiple interventions against risk factors for coronary heart disease in middle aged men at only moderate risk seem to have failed to reduce both morbidity and mortality such interventions become increasingly difficult to justify. This runs counter to the recommendations of many national and international advisory bodies which must now take the recent findings from Finland into consideration. Not to do so may be ethically unacceptable.' Professor Michael Oliver, British Medical Journal 1991

This quote followed a disturbing trial involving Finnish businessmen. In a 10-year follow-up to the original five-year trial, it was found that those men who continued to follow a low saturated fat diet were twice as likely to die of heart disease as those who didn't.

It is not as if this was one negative to set against a whole series of positive trials. In 1998, the Danish doctor Uffe Ravnskov looked at a broader selection of trials: 'The crucial test is the controlled, randomised trial. Eight such trials using diet as the only treatment has been performed but neither the number of fatal or non-fatal heart attacks was reduced.' As Ravnskov makes clear, no trial has ever demonstrated benefits from reducing dietary saturated fat.

Much more here

The Trouble With Science

The article above raises the question of why false beliefs are so prevalent in medical science. The article below by economist Robert Higgs was originally written as a commentary on the twisted "science" of the global warming scare but it applies equally well to medical science. As a much-published academic myself, I agree strongly with his observations

In following the discussion of global warming and related issues in the press and the blogosphere, I have been struck repeatedly by the assumption or expression of certain beliefs that strike me as highly problematical. Many writers who are not scientists themselves are trading on the prestige of science and the authority of scientists. Reference to "peer-reviewed research" and to an alleged "scientific consensus" are regarded as veritable knock-out blows by many commentators. Yet many of those who make such references appear to me to be more or less ignorant of how science as a form of knowledge-seeking and scientists as individual professionals operate, especially nowadays, when national governments - most notably the U.S. government - play such an overwhelming role in financing scientific research and hence in determining which scientists rise to the top and which fall by the wayside.

I do not pretend to have expertise in climatology or any of the related physical sciences, so nothing I might say about strictly climatological or related physical-scientific matters deserves any weight. However, I have thirty-nine years of professional experience - twenty-six as a university professor, including fifteen at a major research university, and then thirteen as a researcher, writer, and editor - in close contact with scientists of various sorts, including some in the biological and physical sciences and many in the social sciences and demography. I have served as a peer reviewer for more than thirty professional journals and as a reviewer of research proposals for the National Science Foundation, the National Institutes of Health, and a number of large private foundations. I was the principal investigator of a major NSF-funded research project in the field of demography. So, I think I know something about how the system works. It does not work as outsiders seem to think.

Peer review, on which lay people place great weight, varies from being an important control, where the editors and the referees are competent and responsible, to being a complete farce, where they are not. As a rule, not surprisingly, the process operates somewhere in the middle, being more than a joke but less than the nearly flawless system of Olympian scrutiny that outsiders imagine it to be. Any journal editor who desires, for whatever reason, to reject a submission can easily do so by choosing referees he knows full well will knock it down; likewise, he can easily obtain favorable referee reports. As I have always counseled young people whose work was rejected, seemingly on improper or insufficient grounds, the system is a crapshoot. Personal vendettas, ideological conflicts, professional jealousies, methodological disagreements, sheer self-promotion, and a great deal of plain incompetence and irresponsibility are no strangers to the scientific world; indeed, that world is rife with these all-too-human attributes. In no event can peer review ensure that research is correct in its procedures or its conclusions. The history of every science is a chronicle of one mistake after another. In some sciences these mistakes are largely weeded out in the course of time; in others they persist for extended periods; and in some sciences, such as economics, actual scientific retrogression may continue for generations under the misguided (but self-serving) belief that it is really progress.

At any given time, consensus may exist about all sorts of matters in a particular science. In retrospect, however, that consensus is often seen to have been mistaken. As recently as the mid-1970s, for example, a scientific consensus existed among climatologists and scientists in related fields that the earth was about to enter a new ice age. Drastic proposals were made, such as exploding hydrogen bombs over the polar icecaps (to melt them) or damming the Bering Strait (to prevent cold Arctic water from entering the Pacific Ocean), to avert this impending disaster. Well-reputed scientists, not just uninformed wackos, made such proposals. How quickly we forget.

Researchers who employ unorthodox methods or theoretical frameworks have great difficulty under modern conditions in getting their findings published in the "best" journals or, at times, in any scientific journal. Scientific innovators or creative eccentrics always strike the great mass of practitioners as nutcases - until their findings become impossible to deny, which often occurs only after one generation's professional ring-masters have died off. Science is an odd undertaking: everybody strives to make the next breakthrough, yet when someone does, he is often greeted as if he were carrying the Ebola virus. Too many people have too much invested in the reigning ideas; for those people an acknowledgment of their own idea's bankruptcy is tantamount to an admission that they have wasted their lives. Often, perhaps to avoid cognitive dissonance, they never admit that their ideas were wrong. Most important, as a rule, in science as elsewhere, to get along, you must go along.

Research worlds, in their upper reaches, are pretty small. Leading researchers know all the major players and what everybody else is doing. They attend the same conferences, belong to the same societies, send their grad students to be postdocs in the other people's labs, review one another's work for the NSF, NIH, or other government funding organizations, and so forth. If you do not belong to this tight fraternity, it will prove very, very difficult for you to gain a hearing for your work, to publish in a "top" journal, to acquire a government grant, to receive an invitation to participate in a scientific-conference panel discussion, or to place your grad students in decent positions. The whole setup is tremendously incestuous; the interconnections are numerous, tight, and close.

In this context, a bright young person needs to display cleverness in applying the prevailing orthodoxy, but it behooves him not to rock the boat by challenging anything fundamental or dear to the hearts of those who constitute the review committees for the NSF, NIH, and other funding organizations. Modern biological and physical science is, overwhelmingly, government-funded science. If your work, for whatever reason, does not appeal to the relevant funding agency's bureaucrats and academic review committees, you can forget about getting any money to carry out your proposal. Recall the human frailties I mentioned previously; they apply just as much in the funding context as in the publication context. Indeed, these two contexts are themselves tightly linked: if you don't get funding, you'll never produce publishable work, and if you don't land good publications, you won't continue to receive funding.

When your research implies a "need" for drastic government action to avert a looming disaster or to allay some dire existing problem, government bureaucrats and legislators (can you say "earmarks"?) are more likely to approve it. If the managers at the NSF, NIH, and other government funding agencies gave great amounts of money to scientists whose research implies that no disaster looms or no dire problem now exists or even that although a problem exists, no currently feasible government policy can do anything to solve it without creating greater problems in the process, members of Congress would be much less inclined to throw money at the agency, with all the consequences that an appropriations cutback implies for bureaucratic thriving. No one has to explain all these things to the parties involved; they are not idiots, and they understand how the wheels are greased in their tight little worlds.

Finally, we need to develop a much keener sense of what a scientist is qualified to talk about and what he is not qualified to talk about. Climatologists, for example, are qualified to talk about the science of climatology (though subject to all the intrusions upon pure science I have already mentioned). They are not qualified to say, however, that "we must act now" by imposing government "solutions" of some imagined sort. They are not professionally knowledgeable about what degree of risk is better or worse for people to take; only the individuals who bear the risk can make that decision, because it's a matter of personal preference, not a matter of science. Climatologists know nothing about cost/benefit considerations; indeed, most mainstream economists themselves are fundamentally misguided about such matters (adopting, for example, procedures and assumptions about the aggregation of individual valuations that lack a sound scientific basis). Climate scientists are the best-qualified people to talk about climate science, but they have no qualifications to talk about public policy, law, or individual values, rates of time preference, and degrees of risk aversion. In talking about desirable government action, they give the impression that they are either fools or charlatans, but they keep talking - worst of all, talking to doomsday-seeking journalists - nevertheless.

In this connection, we might well bear in mind that the United Nations (and its committees and the bureaus it oversees) is no more a scientific organization than the U.S. Congress (and its committees and the bureaus it oversees). When decisions and pronouncements come forth from these political organizations, it makes sense to treat them as essentially political in origin and purpose. Politicians aren't dumb, either - vicious, yes, but not dumb. One thing they know above everything else is how to stampede masses of people into approving or accepting ill-advised government actions that cost the people dearly in both their standard of living and their liberties in the long run



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.


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