You may have noticed that several Olympic athletes are covered in bruises. No, these are not minor injuries obtained during training; they look oddly circular and are located symmetrically all over the body. In fact, they are self-inflicted marks caused by an ancient form of therapy called ‘cupping’. Cupping existed in most cultures and, in recent months, there has been a flurry of interest in it. It seems that cupping is having a comeback, and one does not need to be a clairvoyant to predict that, after the Olympic Games, cupping will become flavour of the month.
Essentially there are two types: dry and wet cupping. Dry cupping involves a cup being placed over the skin. Inside the cup is a vacuum which means the skin is partly sucked into the cup. The suction is usually strong enough to create a hematoma. As the cup has normally a circular shape, the hematoma is circular as well. These are the strange marks we see on the Olympic athletes.
Wet cupping involves superficial injuries to the skin and subsequently the application of a vacuum cup over the injured site. This procedure would draw a small amount of blood into the cup. Wet cupping involves pain and carries the risk of infection. By contrast, dry cupping is harmless and almost painless, when done correctly.
And how is it done correctly? When, about 40 years ago, I worked in a homeopathic hospital, we used dry cupping regularly. There are several techniques, but the method we used was simple: all you need is a small glass cup, some cotton wool and white spirit.
You soak a bit of cotton wool in the white spirit, set it alight, place it in the glass cup and swiftly place it on the skin of the patient. The fire then stops instantly, and the heat creates the desired vacuum. After a while, the vacuum recedes and the cup falls off by itself. This method is simple but I do not advise anyone to do it at home. If you make a mistake, you can burn yourself badly.
Wet cupping is done in much the same way. Only one thing is different: one has to injure the skin before placing the cup over it, and this is what causes the pain. We used to do this with a little device that had multiple needles on it and looked like a miniature hedge hock; alternatively, we employed a scalpel to cut small, superficial incisions into the skin.
Back then, we used cupping mainly for musculoskeletal problems, such as back pain, neck pain or shoulder pain. Did it work? My impression was that it helped ease the pain of most patients. Proper clinical trials to tell us more were not available then.
This lack of evidence continued until recently. I suspect it was Gwyneth Paltrow who prompted some research into cupping. In 2004, she was photographed in a shoulder-free evening dress which displayed the typical circular hematomas of cupping on her back. These photos went around the world and revived interest in this forgotten form of therapy.
Since then, there have been several clinical trials of cupping. They all show that it works for pain; but I am not impressed. The thing is that these studies are of very poor quality, and some report results which, quite frankly, are too good to be true.
Yet I can well believe that cupping is effective — after all, I have seen it working with my own eyes. The question is, how does it work? The procedure I described above is clearly most impressive to the patient. It would therefore be hardly surprising if cupping generated a significant placebo effect. In addition, it might work via a phenomenon called ‘counter irritation’. If you have a mild tooth ache and accidentally hit your thumb with a hammer, you will find that the counter irritation of the hammer made your tooth ache disappear instantly, at least for a while.
Of course, this is not what the cupping therapists will tell you. Depending on which tradition they subscribe to, they will spin a long yarn about life forces, chi or energies being put back into order. Like cupping itself, these explanations originate from the pre-scientific era and do not make the slightest sense in the light of what we know today.
Naturally, all this does not matter to the Olympic athletes who obviously swear by cupping. They want to ease the pain of overexertion and, because of the doping regulations, they have to be careful with many types of medicines. So any drug-free method to alleviate their pain is more than welcome. And whether it works via a pronounced placebo effect, counter irritation or some mystical energy is the last of their worries.
Edzard Ernst, emeritus professor at the University of Exeter, is the author of A Scientist in Wonderland and the awardee of the John Maddox Prize 2015 for standing up for science. He blogs at edzardernst.com.