Posted on 24. Jan, 2009 by Kerry D Friesen, M.D..
Kerry D. Friesen, M.D.
The great tragedy of science — the slaying of a beautiful hypothesis by an ugly fact.
–Thomas Henry Huxley
At one time or another we have all held certain beliefs that later turn out to be not true at all. Most are innocent lies like the tooth fairy or Easter bunny and ultimately no major mental paradigm shift is required to adjust to the “new reality”. ?
You can imagine my surprise to discover while still a D.I.T. (doctor-in-training) that I was being fed a daily diet of less-than scientific—-even downright dangerous information.
Apparently magical-mythical thinking was alive and well, even in the halls of academia.
I discovered this by constantly asking the question “why”?”
“Why give blood products– worse yet—–contaminated blood products to hospitalized patients simply because than their blood count is less than 10 mg/dl”
“Why risk life-threatening anaphylactic reactions by giving platelet transfusions to patients with no clinical or laboratory risk for bleeding”
“Why perform bypass surgery for a known metabolic disease (atherosclerosis), i.e. coronary artery bypass surgery, rather than treat the real cause.
I soon realized that medical science was in fact filled to overflowing, with medical myths.
Another often repeated myth is that bed rest speeds the healing process.
It sounds factual enough.
It even appeals to our “sense-of-the-common” (common sense).
Yet an independent review of 39 different studies confirmed that for many medical conditions strict bed rest was at best not helpful and in many cases harmful.
For that reason I jokingly tell all my elderly patients to “get out of bed”. Then with as somber a face as I can muster I proclaim, “It is a statistical fact that more people die in bed than out of it”. Therefore “get out of bed!”
We’ll come back to the intentional use and abuse of “statistical facts” later.
This next one may surprise you.
Almost everyone, doctors included, believe that the following tests have all been shown to improve survival in otherwise healthy people:
Chest X-rays in smokers
Liver function tests
Kidney function tests
Blood glucose levels
Total cholesterol levels
Mammography in women over 40
Ultrasound examination of the ovaries
Bone density in women
Resting EKG
Ultrasound examination of the aorta in men over 55
PSA in men over 50
The truth is there are absolutely no convincing scientific studies that justify the widespread use of these tests in patients without symptoms.
These tests are neither sensitive enough nor specific enough to detect disease and improve survival in healthy people.
In other words, they are just not that accurate.
That doesn’t keep doctors from ordering these tests inappropriately or patients from requesting a multitude of tests to “see if there is cancer anywhere in me”.
Like the song says
Still, a man hears what he wants to hear, and disregards the rest.
–Simon & Garfunkle, The Boxer
Remember while medical science may lessen uncertainty, it can never fully remove it since life, by its very nature is fraught with frailty and uncertainty.
Correlation-Causation Confusion
While “mini-myths” such as the ones above are easily dispelled, the myth of major monolithic proportions that concerns this book has now gone global.
Thanks to the ultra-effective “know your number” ad campaign implemented by the National Cholesterol Education Program and coordinated by the United States National Institutes of Health (NIH), the entire industrialized world is now counting their cholesterol.
But to what end?
While numerous studies have confirmed the close correlation between high cholesterol and heart disease, an even greater number now substantiate the more important role of multiple non-traditional risk factors.
To assume that cholesterol is the cause of coronary artery disease simply because people with heart disease happen to have elevated cholesterol is just one more example of correlation-causation confusion!
Scientists, statisticians, and now even the creators of a popular animated sit-com recognize that just because event A occurs before outcome B, event A did not necessarily cause outcome B.
A conversation between Homer and Lisa in season seven of the Simpson’s illustrates just how easily we are deceived by this apparent cause-and-effect relationship.
Here is how it played out——a single bear sighting prompted the worried residents of Springfield to spend millions on a “Bear Patrol”
Homer: Not a bear in sight. The “Bear Patrol” is working like a charm!
Lisa: That’s specious reasoning, Dad.
Homer: [uncomprehendingly] Thanks honey.
Lisa: By your logic, I could claim that this rock keeps tigers away.
Homer: Hmm. How does it work?
Lisa: It doesn’t work. (Pause) It’s just a stupid rock!
Homer: Uh-huh.
Lisa: But I don’t see any tigers around, do you?
Homer: (pause) Lisa, I want to buy your rock.
Pharmaceutical Fairy Tales
Besides correlation-causation confusion, errors in deductive reasoning abound. You may not know what to call it, but you will certainly recognize it when you “see” it.
For example, cholesterol drug ads claim a 25% reduction in heart attack risk.
But before you fill your prescription, always ask yourself,
25% of what?
A 25% reduction means nothing unless you know your personal odds of a heart attack!
Here is another way of looking at it. Utilizing the Framingham Risk calculator you discover you have a 2% chance of having a heart attack in the next ten years.
The 25% reduction from drug therapy will decrease your risk by
0.25 x 0.02 = 0.005 ———> 2% – 0.5% = 1.5%
A whopping one-half of one percent.
Not much to get excited about.
Keep in mind that a one-half of one-percent reduction in risk comes at the expense of taking that medicine with all its potential for harm for the rest of your life.
Thanks to a never-ending prime-time stream of pharmaceutical fairy tales, you may “Know Your Number” but do you know your vascular biology?
Measuring blood markers of inflammation and calculating oxidative stress levels is every bit as important as knowing your blood pressure and bank account number.
If you still think that the skin is the largest organ in the body, get ready for a database update.
The vascular endothelium—the trillions of cells that line our blood vessels is without question the largest organ in our bodies. Turn to Chapter __ It’s a Vascular Adventure for how we managed to miss the obvious!
While the quantity of cholesterol present in our bodies may be helpful—quality is clearly more important.
By now almost everyone has heard of so-called ‘good’ (HDL) and ‘bad’ (LDL) cholesterol.
But did you know that there are seven different sub-types of LDL and five different sub-types of HDL?
Only two of the five sub-types of HDL cholesterol are actually “good” and three of the seven sub-types of LDL cholesterol are so damaging to our endothelial cells (see Chapter 7 Pssst! What’s Your Particle Size?) that our risk for heart disease increases more three-fold!
In reality, new studies exploring the real cause of atherosclerosis and heart disease , reveal a complex, sub-cellular environment of lipid (fat) particles, non-fat metabolic trash (such as homocysteine) and chemical messengers such as nitric oxide, inflammatory mediators, antioxidants and free radicals—-all involved in the delicate balance of maintaining vascular health.
While traditional risk-factors such as cigarette smoking, hypertension, diabetes, and obesity remain important, new data emphasize how chronic low-grade inflammation compounded by a genetic predisposition to premature heart disease contribute to the pathogenesis (cause) of atherosclerosis (hardening of the arteries).
In addition, risk rises exponentially as traditional risk factors are combined with newer risks.
Sometimes it takes turning everything completely upside down in order to get it right.
While so much attention has been focused on the problem, (read LDL cholesterol and the medical-pharmaceutical-industrial complex) a token amount of research has been directed toward the solution—HDL.
Helping you understand HDL and how it reverses heart disease is one of the focal points of this blog.
