Swimming with pseudoscience – the cupping craze

I am not a fan of the Olympics. Generally, they are a huge waste of money, and most people across the world have little interest in most of the sports. I have barely noticed what’s going on this year in the Olympics in Brazil, until my news feeds were filled with the junk science craze of the month – cupping.

No, cupping doesn’t mean the protective equipment some male athletes use to protect their groinal (invented word, deal with it) regions. Although, for those athletes, that’s the most important cupping they will ever do.

Apparently, the cupping craze was first noticed because several members US Men’s swim team had these awful looking welts all over their bodies. Michael Phelps, probably the greatest Olympian ever with over 20 gold medals, was sporting several of the cupping welts on his shoulder.

If this feathery reptile has anything to say about medical crazes, cupping has just moved to the top of the list. Let’s look at it, but spoiler alert – see homeopathy.

What is cupping?


Cupping is considered part of traditional Chinese medicine (TCM), which includes alternative medicine like acupuncture, herbal “medicine”, massage, and consumption of animal parts. One of the basic aspects of all TCM is that the body’s qi (pronounced chee), or vital energy, circulates through meridians (channels) that connect to all of the body’s functions and organs.

There is little evidence that TCM is effective. And there’s is no evidence that qi or meridians exist. Simply put, traditional Chinese medicine is quackery. But it has some appeal, especially herbal medicine, which has, very rarely, shown to have some medical benefit.  But the Appeal to Antiquity is very enticing to those who aren’t grounded in science – they think that if the Chinese have been doing this for thousands of years, it must work.

In Trick or Treatment: The Undeniable Facts about Alternative Medicine, by Simon Singh and Edzard Ernst, the authors clearly dispute the science of TCM:

[infobox icon=”quote-left”]Scientists are still unable to find a shred of evidence to support the existence of meridians or Ch’i. The traditional principles of acupuncture are deeply flawed, as there is no evidence at all to demonstrate the existence of Ch’i or meridians. Acupuncture points and meridians are not a reality, but merely the product of an ancient Chinese philosophy.[/infobox]

Moreover, TCM has resulted in the destruction of rare wildlife all over the world. Rhino horn is a popular ingredient in TCM. A whole species of dolphin has been destroyed by TCM. Not only does TCM not work, it destroys the environment. It just makes you want to scream.

Back to cupping.

Cupping therapy uses either heat or mechanical tool to create a vacuum in a cup. A 25-75 mm diameter cup (more like a bell in shape) is placed on the target area of the skin, and the vacuum draws the skin upwards into the cup. The cup stays in place for 5-15 minutes, and it is believed to help treat pain, deep scar tissues in muscle and connective tissue, and other injuries (many related to sports, hence the popularity with American swimmers).

Cupping includes both a dry and wet method. The dry method is rarely used, and doesn’t leave the tell-tale welts we see on the Americans.

Wet cupping is much more popular. It is essentially the same as dry cupping; however, after the suction, the welt is cut with a needle or scalpel to induce bleeding. According to the good folks at Science Based Medicine, it was supposed to remove “stagnant blood, expel heat, treat high fever, loss of consciousness, convulsion, and pain.”

Furthermore, wet cupping isn’t really Chinese. There’s evidence that Arabs have used it since the end of the Roman Empire. Finns have used it since the 15th century. It seems to be a pseudoscience that crossed numerous cultures hundreds of years ago.

I’m guessing that the American swimmers were getting the wet cupping, but even the dry method causes trauma and bruising to the local area of the skin. We’ve all experienced the localized bruising from a type of cupping – we used to call them hickeys. In a sense, the cupping bruise is just gigantic hickeys.

Cupping evidence


Another spoiler alert – cupping is pseudoscience. According to Mark Crislip, my favorite pro-flu vaccination writer, cupping is “like most pseudo-medicine, it is an elaborate placebo with no real effects on real disease.”

News outlets that have a firm belief in false balance have claimed that there is contradictory evidence regarding the efficacy of cupping. That’s just nonsense, the evidence is pretty conclusive – cupping is nothing but bullshit science.

Some of the “cupping believers” rely upon a meta-review that concludes:

[infobox icon=”quote-left”]In this article, the research results show that cupping therapy is promising for pain control and improvement of quality of life, and minimises the potential risks of treatment. Therefore, further studies are needed to determine the potential role of cupping therapy in the treatment of low back pain.[/infobox]

That could be pretty convincing. Except, it’s typical scientific weasel wording. Because it’s a terrible meta-review, and, in fact, the authors admit:

[infobox icon=”quote-left”]Although RCTs (randomized clinical trials) provide a higher quality of evidence, we included non-RCTs in this study because the limited number of RCTs did not provide convincing evidence.[/infobox]

Just to be clear, there was only one (yes, that would be 1) randomized clinical trial in this so called meta review. The other 20 or so articles were case reports (not useful as evidence) or non-randomized clinical trials (completely useless and biased). This “meta-review” violates all the fundamentals of meta-reviews that is to be a systematic analysis that combines the data from a large number of randomized clinical trials.

The one actual RCT that was included in the “meta-review” (I’m going to use scare quotes, because it does not qualify as a real meta-review) is barely acceptable.

Let’s look at all the problems with that RCT:

  1. It included 32 patients. To gain FDA approval, almost every drug requires thousands of patients to make claims about said drug. This is a number that is so low that I cannot state that it is a real clinical trial.
  2. There is tremendous bias in the results. All of the patients wanted the procedure, so, it’s hard to see anything beyond a placebo effect.
  3. The control group did not get standard therapy. All I can conclude is that the group knew it got cupping, it’s not blinded. More bias.

It appears that all of the data that supports cupping is from this one pathetic RCT and a bunch of anecdotes. And I’ve said this at least 100 times, anecdotes do not equal data. Moreover, more anecdotes do not equal more data.

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Wrapping it up


Some may say “well, provide us with evidence that it doesn’t work.” That’s not science, it doesn’t “prove” a negative. Real science doesn’t waste its time on implausible therapies whose basis has already been shown to be nonsense. Further, let me blunt – sometimes the absence of evidence is really evidence of absence (my bastardization of Carl Sagan’s statement that was really meant to apply to an infinite universe, not biomedical research, which is much more finite).

The lack of evidence is the lack of evidence, unless you think the argument from ignorance is useful to rational science. But right now, the medical effectiveness of cupping is both physiologically implausible and is unsupported by any reliable science.

Steven Novella, in an article in Science Based Medicine, concludes that:

[infobox icon=”quote-left”]One manifestation of this is the specific claims for what the treatment treats. The target ailments tend to gravitate toward common subjective symptoms. Low back pain, muscle pain, joint pain, fatigue, and headaches are all common targets. This is a clear sign that the claims made for these treatments are being driven by market forces, not plausibility, evidence, research, or science.

Another manifestation is the alleged mechanisms cited to justify the treatment. These tend to follow the popular narratives of the day, and again are driven by market forces, not science. Centuries ago cupping would release chi. Today it is used to expel unnamed toxins, increase blood flow, or activate the immune system.

There is no compelling reason to believe that cupping does any of these things. These are just the available hand-waving justifications.[/infobox]

Edzard Ernst, one of the leading scientists in debunking junk medicine, has stated

[infobox icon=”quote-left”]In conclusion, this overview of SRs (systematic reviews) suggests that cupping may be effective for reducing pain. The evidence is insufficient for other indications. All SRs are based on primary studies with a high risk of bias. Therefore, considerable uncertainty remains about the therapeutic value of cupping.[/infobox]

His words, “maybe effective” are almost completely contradicted by his claims that the studies have a “high risk of bias.” This is important in using a critical mind – although most of us skeptics rely on meta-reviews (or systematic reviews) as the basis of accepting or rejecting a claim, critically analyzing those reviews is part of the job. The meta reviews for cupping just don’t make a credible case.

One more thing

There are risks to cupping, especially the wet version. Infections would be the most serious, although scarring, damage to tissues, and a few other issues that would be troubling, especially to swimmers whose skin is in contact with a moist environment as a part of the job. If you want a placebo, you basically want 0 risk. But if you know that cupping doesn’t work, any risk is way too high.

Michael Phelps wins gold medals because he’s a freak athlete who trains at a level that is beyond my imagination. He doesn’t win those medals because he has a worthless and pseudoscientific procedure done to him. I don’t care what he says about cupping, it’s an anecdote at best.

But I’ll make a bet that like gluten free diets and the anti-vaccination movement, cupping will become a thing. And that just means I should get my cupping license and make a few bucks to support this website.

Just kidding. Or maybe not.


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The Original Skeptical Raptor
Chief Executive Officer at SkepticalRaptor
Lifetime lover of science, especially biomedical research. Spent years in academics, business development, research, and traveling the world shilling for Big Pharma. I love sports, mostly college basketball and football, hockey, and baseball. I enjoy great food and intelligent conversation. And a delicious morning coffee!