[Blythe Nilson, CFI Canada Chair of Science]
Every four years the Olympics lets us know what sort of pseudoscience is popular among athletes. Four years ago it was “magic tape” (KTape ) and in 2016 it’s cupping. Many athletes, especially the swimmers, are sporting large, circular, suction-inflicted wounds that supposedly help their tired muscles recover more quickly between events. Respectable news outlets, like the New York Times and the CBC, responsibly reported that cupping is not based on science and there is no evidence to suggest it works at all for any of the ailments it supposedly addresses. Others however, like Global TV BC, have credulously promoted the practice as if it were real medicine. Instead of interviewing physicians or sport medicine experts, Global brings on acupuncturists and Chinese “traditional medicine” proponents. With little or no scientific training, these practitioners base their “evidence” on anecdotes and poorly run, severely biased, studies, and benefit from the publicity as they sell cupping as part of their practices.
Cupping originated thousands of years ago, based on the pseudoscientific idea that “toxins”, “qi” or “bad blood” can be removed from the body using suction. A glass or metal cup is heated and placed on the skin. As it cools down the air inside reduces in volume, creating suction on the surface. This breaks small blood vessels in the dermis and draws the blood to the surface where red blood cells die and their contents leaks into the tissue, creating a red circle. It’s basically a hickey. Some practitioners make incisions in the center of the cupped area in order to draw some blood out directly. Nasty burns or infections can result if practitioners are not careful. Traditionally, cups were heated by placing small candles inside them or filling them with hot smoke; today suction can be created mechanically with an electric device.
Modern believers claim that “stagnant blood” lingers in tired muscles and can somehow be drawn through the muscle, the fascia and layers of connective tissue to finally pass through the skin and be deposited in the epidermis. If that were possible the powerful suction required would do a great deal of harm to not only the muscle but all the tissues nearby. Tired muscles which contain pools of “stagnant” blood would be so severely damaged that the athlete would be out of the competition. The only stagnant blood involved here is the blood that escaped the blood vessels damaged by the cupping itself!
Does it work? Well, since pain-relief is the desired outcome, and pain resides purely in the brain, it’s easy to experience relief if you really believe it should happen. But we won’t see cupping used for anything that we can objectively measure and it’s heartening to see that swimmers who aren’t covered in blotches are winning medals.
Learn more here:
NYT
CBC
David Gorski
Steven Novella