Cupping is the new celebrity snake oil

If, like me, you were wondering about those funny, round, red welts being sported by Olympians like Michael Phelps, then the answer is "cupping".

Yes, that's cupping as used by the ancient Egyptians, Persians and Chinese, and by the medically-misinformed practitioners of medieval Europe. Basically, a cup or glass of some kind is placed on the skin and heat or a vacuum is applied to suck the air out of it. The idea is supposedly to influence the flow of energy (or "qi") through the body, and to mobilize local blood flow in such a way as to somehow eliminate toxins from the body and even promote healing and pain relief.

It's the latest fad among entertainment celebrities, who are always in search of new talking points for their Instagram pages (including Lena Dunham, Jennifer Anniston, Justin Bieber and Gwyneth Paltrow), and a few sports celebrities (most notably swimmer Michael Phelps). However, if it sounds like snake oil, or just something from Monty Python, you may not be far wrong.

As with so many trendy alternative therapies, there appears to be little or no scientific evidence of its efficacy. A 2012 meta-analysis in the journal of the US Public Library of Science, PLOS ONE, found that, for a few conditions, cupping may have conferred some benefit. However, some 85% of the studies involved had a "high risk of bias", particularly in that they were not blinded or placebo-controlled studies, suggesting that a grain of salt may need to be taken with them. The medical community in general treats cupping as a pseudoscience with absolutely no medical evidence of any efficacy at all, except perhaps a psychosomatic one in some cases.

Cupping is unlikely to be actively dangerous, other than some unnecessary bruising and a risk of infection from those types of cupping that also involve cuts to the skin. But, like many other alternative therapies, the main worry is that such unproven treatments may steer people away from other evidence-based therapies that actually do work. We should not be basing our medical decisions based on Instagram popularity.