Cupping is a so-called alternative medicine (SCAM) that has existed in several ancient cultures. It recently became popular when US Olympic athletes displayed cupping marks on their bodies, and it was claimed that cupping is used for enhancing their physical performance. There are two distinct forms: dry and wet cupping.

Wet cupping involves scarring the skin with a sharp instrument and then applying a cup with a vacuum to suck blood from the wound. It can thus be seen (and was traditionally used) as a form of blood-letting. Wet cupping is being recommended by enthusiasts for a wide range of conditions. But does it work?

This study compared the effects of wet-cupping therapy with conventional therapy on persistent nonspecific low back pain (PNSLBP). In this randomized clinical trial, 180 participants with the mean age of 45±10 years old, who had been suffering from PNSLBP were randomly assigned to wet-cupping or conventional treatment. The wet-cupping group was treated with two separate sessions (4 weeks in total) on the inter-scapular and sacrum area. In the conventional treatment group, patients were conservatively treated using rest (6 weeks) and oral medications (3 weeks). The primary and the secondary outcome were the quantity of disability using Oswestry Disability Index (ODI), and pain intensity using Visual Analogue Scale (VAS), respectively.
The results show that there was no significant difference in demographic characteristics (age, gender, and body mass index) between the two groups. Therapeutic effect of wet-cupping therapy was comparable to conventional treatment in the 1st month follow-up visits. The functional outcomes of wet-cupping at the 3rd and 6th month visits were significantly superior compared to the conventional treatment group. The final ODI scores in the wet-cupping and conventional groups were 16.7 ± 5.7 and 22.3 ± 4.5, respectively (P<0.01).

The authors concluded that wet-cupping may be a proper method to decrease PNSLBP without any conventional treatment. The therapeutic effects of wet-cupping can be longer lasting than conventional therapy.

Perhaps the authors were joking? In any case, their conclusions cannot be taken seriously. Why? There are several reasons, but the most obvious ones are:

  1. There was no adequate control of the presumably substantial placebo effects of wet cupping.
  2. The control group received a treatment that is known to be ineffective or even detrimental.

For people with acute low back pain, advice to rest in bed is less effective than advice to stay active. Thus comparing wet cupping to a control group treated with bed rest is bound to generate a false-positive outcome for wet cupping.

My final point is perhaps the most important: wet cupping can lead to serious complication, and I therefore do not recommend it to anyone – other than masochists, perhaps.

The authors of this systematic review aimed to summarize the evidence of clinical trials on cupping for athletes. Randomized controlled trials on cupping therapy with no restriction regarding the technique, or co-interventions, were included, if they measured the effects of cupping compared with any other intervention on health and performance outcomes in professionals, semi-professionals, and leisure athletes. Data extraction and risk of bias assessment using the Cochrane Risk of Bias Tool were conducted independently by two pairs of reviewers.

Eleven trials with n = 498 participants from China, the United States, Greece, Iran, and the United Arab Emirates were included, reporting effects on different populations, including soccer, football, and handball players, swimmers, gymnasts, and track and field athletes of both amateur and professional nature. Cupping was applied between 1 and 20 times, in daily or weekly intervals, alone or in combination with, for example, acupuncture. Outcomes varied greatly from symptom intensity, recovery measures, functional measures, serum markers, and experimental outcomes. Cupping was reported as beneficial for perceptions of pain and disability, increased range of motion, and reductions in creatine kinase when compared to mostly untreated control groups. The majority of trials had an unclear or high risk of bias. None of the studies reported safety.

Risk of bias of included trials. “+” indicates low risk of bias, “−” indicates high risk of bias, and “?” indicates unclear risk of bias.

The authors concluded that no explicit recommendation for or against the use of cupping for athletes can be made. More studies are necessary for conclusive judgment on the efficacy and safety of cupping in athletes.

Considering the authors’ stated aim, this conclusion seems odd. Surely, they should have concluded that THERE IS NO CONVINCING EVIDENCE FOR THE USE OF CUPPING IN ATHLETES. But this sounds rather negative, and the JCAM does not seem to tolerate negative conclusions, as discussed repeatedly on this blog.

The discussion section of this paper is bar of any noticeable critical input (for those who don’t know: the aim of any systematic review must be to CRITICALLY EVALUATE THE PRIMARY DATA). The authors even go as far as stating that the trials reported in this systematic review found beneficial effects of cupping in athletes when compared to no intervention. I find this surprising and bordering on scientific misconduct. The RCTs were mostly not on cupping but on cupping in combination with some other treatments. More importantly, they were of such deplorable quality that they allow no conclusions about effectiveness. Lastly, they mostly failed to report on adverse effects which, as I have often stated, is a violation of research ethics.

In essence, all this paper proves is that, if you have rubbish trials, you can produce a rubbish review and publish it in a rubbish journal.

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