Tuesday, November 20, 2012

Bloodletting makes a comeback?

In a recent search for science news that I could write about, I found this recent article in BMC Medicine titled "Effects of phlebotomy-induced reduction of body iron stores on metabolic syndrome: results from a randomized clinical trial". Metabolic syndrome is a collection of risk factors generally related to obesity. Phlebotomy-induce reduction of body iron store is basically bloodletting.
Schematic of common bloodletting points

If you've never heard of bloodletting, the idea is that you cut someone and let them bleed for a while. This was thought to heal a wide variety of illnesses including seizures, fevers, stroke, heart attack, gastrointestinal problems, and more. If you fell ill in the late 18th century it was almost a guarantee that your physician would try bloodletting. Although it sounds like a gruesome treatment today, it actually has some ties to some modern alternative medicine ideas.1

Bloodletting originated at a time when the circulatory system was not understood. Physicians before the year 130 thought that veins carried blood and arteries carried air. Since the blood in the veins doesn't circulate, they reasoned, it can become stagnant in the extremities. The cure was to bleed a person to get rid of the stagnant blood. 

Even after the circulatory system was understood, though, the practice continued. Eventually physicians would only prescribe the treatment - barbers would do the actual procedure. In fact, bloodletting is the origin for the well recognized barber pole; the red signifies blood, the white a tourniquet, and the pole itself a rod the patient would squeeze to dilate the veins.

Bloodletting continued well after science based medicine should have put a stop to it, but it continued for the same reason that modern alternative medicine is popular - it had a good story. Your body has toxins that need to be removed. Bloodletting is a rejuvination for your body. It restores your body's natural state and energy. But it's all wrong - no matter how good it sounds.

Of course, modern medicine still has real uses for bloodletting (or at least a similar practice). The treatment for hemochromatosis (too much iron in the blood) and polycythemia (too many red blood cells) is venesection.The study I cited at the beginning of this article suggests that patients suffering from high blood pressure may benefit from regular removal of blood. Does this mean that bloodletting was a good practice after all? Not really. Bloodletting was used extensively as a cure for just about everything. Getting it right in one specific case does not validate the idea as a whole. If a patient in the 1850s suffering from symptoms related to high blood pressure was treated with bloodletting, their situation may have improved. However, high blood pressure is often subclinical (meaning you don't notice you have high blood pressure. Instead you notice something that the high blood pressure causes, like headaches for example).

We don't need to revert to bloodletting as a cure all. You may wonder why I'm stating the obvious, but many alternative medicine practices make comebacks. With the right story I wouldn't be surprised to hear Oprah, Dr. Oz, or some other celebrity telling you how bloodletting (they'll call it something more appealing) can cure cancer, rejuvenate you, or restore your body's natural energy state. After all, they've told us stories crazier than that.

[1] I actually found this article while writing a post about some crazy medical practices of the past and how they are similar to modern alternative medicine. Just you wait, it's gonna be good!
[2] Venesection sounds so much better than bloodletting, right?