Medical Mythology in the 21st Century

time-magMedical Myths Have an Inexplicable Resilience. Some Can Last Centuries

The Four Humors Theory of medicine, wherein health depended on the proper balance of the Four Humors: Blood, Brown Bile, Yellow Bile and Phlegm, holds the record for long running medical myths. All the Modern Medical Myths, into which we are about to plunge, will be pressed to compete with the Four Humors.

hippocratesHippocrates is credited with this persistent theory, and perhaps that gives us a good clue: If the theory is endorsed by one of the medical high priests, it is likely to endure. Well, endure it did. Four Humors lasted well in to the 19th century—the age of reason.

But is it the age of reason?

Or do we have a primordial need for myths. This is not a philosophy blog, but if the answer is yes, the medical profession is certainly fulfilling the need. Here are ten myths. Lesser in scope to be sure, but as firmly embedded as the Four Humors Theory likely was.




  1. Saturated fat is bad for you.
  2. Dietary cholesterol is bad for you.
  3. Whole grain is good for you.
  4. Aerobic exercise is good for you.
  5. Avoid intense exercise.
  6. Vegetables are healthier than meat.
  7. Adult onset diabetics can eat whole grain and fruit.
  8. Statins are beneficial.
  9. Beta-blockers are beneficial
  10. Ezetimibe is beneficial.


We are cheating a bit here. When we delve into drugs that basically derail internally regulated processes, like cholesterol management, biological hell inevitably breaks loose. Some portion of the doctoring class may duly subscribe to meddling with bodily processes, but without exception (that we know of), the innumerable efforts of drug companies to introduce drugs that alter internal regulated hormonal or biochemical levels, have done more harm than good. In the case of some drugs, far more. Yet they somehow become part of mainstream medicine, garnering membership into the category of Myth: something believed true that is not.

But if the above list raises an eyebrow or two, you are in good company. I (Davis) have subscribed to several of these.

Vegetables better

And why not? There was always some logic, something that made sense. Why wouldn’t vegetables be healthier than meat? You can eat vegetables raw. They “look” healthier somehow. And they don’t mind being eaten. But it simply isn’t so. By almost any measure vegans are not healthier than omnivores.

And what could be wrong with aerobic exercise?

Who doesn’t feel great after a one-hour jog. Great because we have just done wonders for our health. Great because we have reaffirmed our cherished membership in the worldwide brotherhood and sisterhood of joggers. Great because it is, at least for the moment, over. And then there’s the runner’s high. Never got that one. (I, Dr. Mike, got this one big time; an hour into a long run and I was singing arias to the whole blessed world!) But it’s crappy exercise. Sorry. It’s better than couch potato, but what you are telling your primordial energy management system is that you are migrating. And the primary reason for migrating is to find new food. New food? Uh, oh—famine coming—conserve. Shut down inessential healing of bodily processes. And this is exactly what happens. HDL, the “good” cholesterol, which, if boosted, will dramatically reduce risks of both heart disease and cancer, is hardly affected by aerobic exercise. Bummer. There are exercises that will boost this lifesaving cholesterol, but these exercises mimic hunting, not migration. More on that here.

We want to cover the list though. The last three are drugs. Here is the all cause mortality benefit for the three mentioned.

  • Statins – Does not lower mortality
  • Eztimibe – Increases mortality
  • Beta blockers – Increases mortality

And, they all have side effects. No benefit for one, and a clear detriment for the other two, yet the three are widely prescribed and widely believed in. But Lets Get to the Meat

Saturated Fat

Saturated fat is slightly better for you that the other types, monounsaturated and polyunsaturated. But (as always) it isn’t that simple. The fats come in varying lengths too and the body has specific needs for specific fats that may or may not arrive in the next meal. So the body snips and splices these fats to create what it needs. The fats that make up cells walls and all the rest resemble the fat we ate about as much as a coffee table resembles on oak tree. However, the preferred raw material for all this cellular carpentry is the saturated fat molecule. The body can make all the needed fats from this. Mono and poly, less so. Trans-fat is frequently lumped with saturated fat. (It is always so lumped by those wishing to make a case against saturated fat.) Trans-fat is a man-made fat that, unfortunately, deceives the body. Its tale can be found here. Saturated fat is healthy. Mother’s milk is highly saturated. Butter is saturated. Yet this myth will not go away. It’s always “cut down on saturated fat” and never a reason why.

Dietary Cholesterol

egg-yolkCirculating cholesterol, the type that can, depending on its composition, cause heart disease, is highly regulated. This means that if you eat more, your body will make less, and vice versa. The internal levels will remain the same. The cholesterol content of the food you eat DOES NOT MATTER. There is no controversy about this, yet it is widely believed that food high in cholesterol should not be eaten. And this strange belief is upheld in many quarters by the medical profession today. For instance, they say things like; ‘don’t eat egg yolks.’

Whole Grain

Better is not the same as good. Whole grain is better for you. Better, that is, than refined grain. But is grain of any sort good for you? Short answer: no. Long elaborate scientific answer: no. We aren’t evolved to eat grain. It’s cheap, and can keep us alive, but that’s about all. It has very little nutritional value, especially compared to colorful vegetables. But it has this mythological status as a healthy food.

Intense Exercise

heart-rateStudy after study has shown intense, but brief, exercise to be far more beneficial than aerobic, yet every aerobic machine in the gym has some “red-line” limit, and most of the gym staff say not to push your heart to extreme. Although a doctor should be consulted before starting any exercise program, almost everyone will receive far more benefit from exercise that is intense, but short.

Adult Onset Diabetics Should Eat Whole Grain and Fruit

This is a favorite and is so immediately illogical that it is amazing that it is a recommendation from both the British National Health Service and the American Diabetes Association. Adult onset diabetes is, very simply, a reduced capacity to metabolize glucose. And so the completely obvious solution is to reduce dietary glucose. Wheat of any sort is converted to almost 100% glucose by the intestines, and fruit is a mix of glucose and fructose. The liver converts all that fructose to, you guessed it, yet more glucose (or results in higher triglycerides.) This makes as much sense as pouring water on a drowning man. But it’s a Myth, so no need for reality to enter the picture.


The age of reason? Don’t think we are quite there yet. But stayed tuned. In a few weeks, the sequel: Ten More Medical Myths


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