Central  South  Dakota Medical News
The Clinical View
by P.E. Hoffsten, M.D.
11 July 2002

WHAT IS EVIDENCE-BASED MEDICINE?

     Since the dawn of recorded history regarding medicine, healthcare providers have prescribed various potions, pills, elixirs, powders and plasters.  To the ancients, recommendations were based upon their personal experience.  No one really knows how many people they cared for or what the results were.  Down through the ages, various medications were found to be effective for certain well-recognized disease states.  An example would include autumn crocus that had a very potent drug in it called colchicine.  This was known to be effective for treating gout and still is used in some quarters today but the side effects of abdominal cramping and diarrhea that comes with this drug, have lead to it’s being supplanted by other more effective, less toxic medications.

         In 1938, penicillin was introduced as the first modern antibiotic.  It is still used for many different types of infections today, now 64 years later.  There has never been a study done to treat some people with pneumonia. with nothing and some people with pneumonia with penicillin to show that penicillin works better than nothing.  Thus, in the strictest sense of the word, there is no evidence that penicillin works for pneumonia.  We know that if we take penicillin and mix it with pneumococci, the organism that often causes pneumonia, the pneumococci  are killed.  It just made sense to believe that trying penicillin for pneumococcal pneumonia would be an effective treatment.  Thus, there is good evidence that penicillin kills pneumococci but there is no evidence that shows that it cures pneumococcal pneumonia.  Yet that was the backbone of treatment for many years.

     As our medical community has become more sophisticated and our citizens more demanding, the question, “Where is the evidence that this drug is effective?”  is commonly heard.  Now, our Food and Drug Administration requires that any new drug brought to the market have credible evidence that it is effective to treat the target disease and free enough of side effects to make the benefit to risk ratio favorable.  No medication is risk free.

    The most recent issue of the Journal of American Medical Association had two studies and an editorial regarding the use of Vitamin E to prevent Alzheimer’s disease.  We still have no meaningful concept of the cause of Alzheimer’s disease, but over the years many investigators have expressed the view that it is caused or at least made worse by “oxidative stress”.  Broadly speaking oxidative stress can be thought of as a tendency to be burned or deteriorate kind of like that old plastic or old newspaper in the attic that once was pliable and useful.  After time, old plastic and newspapers become brittle,  friable and breakup when you handle them.  Oxidative stress can be thought of as that effect upon the human body.  The less oxidative stress a person has the better their tissues are preserved.

     Examples of oxidative stress include infections, cigarette smoking, excessive sun exposure, high blood pressure, high blood sugars, and abnormal cholesterols.  These factors over time tend to decay and deteriorate body tissues.  With the idea that oxidative stress leads to deterioration of the brain causing Alzheimer’s disease, investigators began to see if agents that combat oxidative stress might be helpful in preventing or delaying the progression of Alzheimer’s disease.  Thus, the term “anti-oxidant” has become a buzz word in the health maintenance and nutrition stores.  Vitamin E turns out to be the premiere antioxidant.  Estimates are that as many as 17% of our population take Vitamin E on a regular basis.

     Where is the evidence that Vitamin E has any beneficial effect?  The two articles that appeared in the Journal of American Medical Association this week came to the same conclusion.  One study was done in Chicago in 800 people.  The other was done in Holland on 5,600 people.  Both studies came to the same conclusion, that those individuals who had diets high in Vitamin E had as much as a 70% decrease in the likelihood that they would develop Alzheimer’s disease during the period of the study.  While both studies were relatively short (4 years, 6 years), they both came to the same conclusion that Vitamin E either slowed the progression of or prevented Alzheimer’s disease.  The studies made the point “that their evidence” showed that diets rich in Vitamin E prevented Alzheimer’s disease but they could not show that the pill supplement had any effect. Now what do you do with that evidence?

    In my opinion, there is enough information to say that Vitamin E probably is beneficial in disease prevention for both Alzheimer’s disease and cancer of the prostate.  Granting that the two studies above did not show a benefit from the use of supplemental pills, to me the story is very similar to that of penicillin.  There has never been a study that shows that penicillin is better for pneumonia than nothing but we still use it.  The antioxidant concept in the oxidative stress theory are based on years of study.  I would predict, that in the future, stronger evidence yet will come to the forefront endorsing the use of Vitamin E, both in diet and supplements.  By the way, diets rich in Vitamin E contain lots of grains, nuts, milk, and egg yokes.  I will say again, those people who don’t eat eggs, because they are afraid of cholesterol, are exposing themselves to a malnutrition state.  Egg yokes are the riches source of neurotransmitters for your brain in addition to being a rich source of Vitamin E.  Everyone should eat at least an egg a day.

     As a closing note, it can be stated that there has never been a case of Vitamin E intoxication and no demonstrated side effects from the use of this vitamin.  Now there is evidence-based medicine stating that a Vitamin E enriched diet decreases the likelihood of Alzheimer’s disease.  I predict in the future, Vitamin E supplements will be shown to be equally effective.