Last week’s TIME Magazine has an excellent article about a very important trend in healthcare:  evidence-based medicine.  It’s not long, and I urge you to read it.

The surprising truth is that the scientific practice of medicine is a very new development.  For centuries medicine was an apprenticeship in which traditional treatments were handed down from teacher to pupil without any objective investigation of either the mechanisms of disease or the effectiveness of treatment.  Even after the enlightenment and the spread of the scientific method, virtually no effective treatments had been developed for any illness.  Before the mid-nineteenth century, when Dr. Ignaz Semmelweis saved countless lives by insisting that doctors wash their hands before attending to women during childbirth, it is very unlikely that being treated by a physician for any condition did more good than harm.  (For those interested in history, a fascinating review of the history of medicine is in this Wikipedia article.)

The actual rigorous testing of treatments (whether they be medications, or surgeries, or psychotherapy) to see whether patients randomized to receive those treatments do better than patients randomized to receive placebo is embarrassingly recent.  Evidence-based medicine is simply educating doctors to look for such studies and to base their treatment of patients on the best scientific evidence available.  Evidence-based medicine began to be recommended in the 1990s!  As the TIME article details, it led to the realization that we were mistreating lots of diseases and lots of patients.  From treating irregular heartbeats in patients with heart attacks to estrogen replacement therapy after menopause, we were using medications that we thought should have been helping patients.  But we only found out we were hurting people after randomized trials were done.

The criticisms of evidence-based medicine in the article strike me as silly.  Practicing evidence-based medicine doesn’t mean I have to ignore my patients’ preferences or values.  It doesn’t mean I can’t be compassionate.  It doesn’t mean I have to prescribe the same thing for everybody.  Practicing evidence-based medicine just means that for some diseases, I know what works and what doesn’t.

(Thanks to my patient Mr. Milton Jupiter for pointing the TIME article to me.)

This week the Food and Drug Administration approved orlistat for over-the-counter sales.  Orlistat is currently available as the prescription medicine Xenical, and will be marketed over-the-counter under the brand name alli.

The details of the announcement, and reactions by various weight loss experts are detailed in this interesting LA Times article.

Orlistat works by blocking the absorption of fat from the intestine into the blood stream, thereby causing fewer of the calories of each meal to stay in the body.  Unfortunately, this yields only a modest weight loss, and only when used in conjunction with diet and exercise.  This is why, as the article reports, Xenical has not sold very well.

The side effects are also annoying.  Since orlistat blocks fat absorption, it causes greasy stools and diarrhea.  (That’s almost worse than lavender oil!)

GlaxoSmithKline hopes that making alli available over the counter will increase the number of patients who use it.  I hope my patients just eat sensibly and exercise.

Tangential Miscellany:

The Pedometer Project started two weeks ago, and the participants have already walked a total of over a million steps!  If you’d like to join, or if you don’t want to participate in the contest but would just like a pedometer, let me know.

A popular misconception (at least in health-conscious Southern California) is that natural substances are in general safer than artificial ones.  Some people who would never take a prescription medication without educating themselves about the possible side effects use natural products without a second thought.

Last week’s New England Journal of Medicine published an article which is a startling example of natural products having potent and harmful health effects.  The article reports the case studies of three healthy prepubescent boys who developed breast tissue enlargement (gynecomastia).  Blood testing showed that their endogenous hormone levels were normal for prepubescent boys, meaning their bodies were not making excess estrogen which would cause the gynecomastia.

Detailed questioning revealed that all three boys were using topical products containing lavender oil or lavender and tea tree oil.  One boy’s mother was regularly applying a balm containing lavender oil on his skin.  The second boy was using a hair styling gel and a shampoo both of which contained lavender oil and tea tree oil.  The third boy was using lavender-scented soap and lavender-scented skin lotions.  All three boys’ gynecomastia resolved after discontinuation of these products.  Testing in the laboratory of lavender oil and tea tree oil on human breast tissue showed that these oils have estrogen-like effects.

Is there a larger lesson here other than that we should avoid lavender oil and tea tree oil?  Only that we should not assume anything about a substance’s safety from the fact that it’s natural.  Both humans and nature have produced biologically potent dangerous chemicals.  The only way to distinguish them from safe chemicals is to study their effects.