Last Saturday on the Natural Health Show, during my weekly Radical Remedies segment, I talked about medicinal leeches. It’s an old therapeutic practice that is now considered very radical, mostly because of the general appearance of these critters. The practice dates back to 800 BC in India and ancient Greece.
The general idea was to use leeches to draw out blood in order to keep the four humors of ancient medical philosophy in balance. The founder of this philosophy was Galen, who lived in ancient Greece and is a man considered by many to be one of the fathers of modern medicine. The four humors were blood, phlegm, black bile, and yellow bile. It was believed that too much or too little of any one of them could lead to disease. Too much blood would manifest itself as inflamed, reddened skin, so it was believed that letting out blood in a controlled fashion would fix the underlying cause of the illness.
But now let’s take a look at these little critters through the lens of modern science. The black common leech (Hirudo medicinalis) that we see in our lakes and rivers uses over 60 different proteins during the feeding process. Some of these act as anticoagulants (substances that prevent the clotting of blood), the prime example being Hirudin. Some act as platelet aggregation inhibitors (platelet aggregation being necessary for blood clotting), examples being calin, apyrase and collagenase, and some act as local anesthetics so that we do not feel the leech attaching and biting into our skin to access the blood. There are also substances that dilate blood vessels to make blood flow in an easier fashion as well as some inhibitors of inflammation.
All of these listed properties can be used for a number of medical conditions. Hirudin for example is now synthesized in laboratories and has been used in medicine to dissolve blood clots in heart arteries, something that occurs during heart attacks. The platelet aggregation inhibitors could potentially be used to prevent strokes and in conditions which are marked with hyper-coagulability, such as prolonged immobilization after surgical procedures. This is especially helpful to prevent blood clots from traveling to the lungs where they produce lung emboli causing serious medical outcomes. On the other hand, the substances that have anti-inflammatory properties could be used in many conditions marked by excess inflammation.
Modern Day Uses
Today, leech therapy is making a comeback, especially in microsurgery where they are used to stimulate blood circulation in reattached organs (such as eyelids, fingers, and ears) and to relieve blood pooling in venous insufficiency (where blood is not circulated properly in veins due to their excessive dilatation and weakening of their walls). It is also used in the treatment of varicose veins (the dilated inflamed veins commonly found on lower legs) and in osteoarthritis. Bloodletting also stimulates the bone marrow to produce new blood cells, and this rejuvenates blood.
Of course, I am not asking you to go to your local pond to look for leeches in order to attach them to yourself. There is a much more practical and helpful approach that basically serves the same purpose. By simply donating blood at the local Canadian Blood Services we are doing the same and at the same time saving lives.