Cupping: How It Works (And How It Doesn’t)

Good Health By The Cup?

In Tuesday’s newsletter, we asked you for your opinion of cupping (the medical practice), and got the above-depicted, below-described, set of responses:

• About 40% said “It may help by improving circulation and stimulating the immune system”
• About 26% said “I have never heard of the medical practice of cupping before this”
• About 19% said “It is pseudoscience and/or placebo at best, but probably not harmful
• About 9% said “It is a good, evidence-based practice that removes toxins and stimulates health”
• About 6% said “It is a dangerous practice that often causes harm to people who need medical help”

So what does the science say?

First, a quick note for those unfamiliar with cupping: it is the practice of placing a warmed cup on the skin (open side of the cup against the skin). As the warm air inside cools, it reduces the interior air pressure, which means the cup is now (quite literally) a suction cup. This pulls the skin up into the cup a little. The end result is visually, and physiologically, the same process as what happens if someone places the nozzle of a vacuum cleaner against their skin. For that matter, there are alternative versions that simply use a pump-based suction system, instead of heated cups—but the heated cups are most traditional and seem to be most popular. See also:

National Center for Complementary and Integrative Health | Cupping

It is a dangerous practice that often causes harm to people who need medical help: True or False?

False, for any practical purposes.

• Directly, it can (and usually does) cause minor superficial harm, much like many medical treatments, wherein the benefits are considered to outweigh the harm, justifying the treatment. In the case of cupping, the minor harm is usually a little bruising, but there are other risks; see the link we gave just above.
• Indirectly, it could cause harm by emboldening a person to neglect a more impactful treatment for their ailment.

But, there’s nothing for cupping akin to the “the most common cause of death is when someone gets a vertebral artery fatally severed” of chiropractic, for example.

It is a good, evidence-based practice that removes toxins and stimulates health: True or False?

True and False in different parts. This one’s on us; we included four claims in one short line. But let’s look at them individually:

• Is it good? Well, those who like it, like it. It legitimately has some mild health benefits, and its potential for harm is quite small. We’d call this a modest good, but good nonetheless.
• Is it evidence-based? Somewhat, albeit weakly; there are some papers supporting its modest health claims, although the research is mostly only published in journals of alternative medicine, and any we found were in journals that have been described by scientists as pseudoscientific.
• Does it remove toxins? Not directly, at least. There is also a version that involves making a small hole in the skin before applying the cup, the better to draw out the toxins (called “wet cupping”). This might seem a little medieval, but this is because it is from early medieval times (wet cupping’s first recorded use being in the early 7th century). However, the body’s response to being poked, pierced, sucked, etc is to produce antibodies, and they will do their best to remove toxins. So, indirectly, there’s an argument.
• Does it stimulate health? Yes! We’ll come to that shortly. But first…

It is pseudoscience and/or placebo at best, but probably not harmful: True or False?

True in that its traditionally-proposed mechanism of action is a pseudoscience and placebo almost certainly plays a strong part, and also in that it’s generally not harmful.

On it being a pseudoscience: we’ve talked about this before, but it bears repeating; just because something’s proposed mechanism of action is pseudoscience, doesn’t necessarily mean it doesn’t work by some other mechanism of action. If you tell a small child that “eating the rainbow” will improve their health, and they believe this is some sort of magical rainbow power imbuing them with health, then the mechanism of action that they believe in is a pseudoscience, but eating a variety of colorful fruit and vegetables will still be healthy.

In the case of cupping, its proposed mechanism of action has to do withbalancing qi, yin and yang, etc (for which scientific evidence does not exist), in combination with acupuncture lore (for which some limited weak scientific evidence exists). On balancing qi, yin and yang etc, this is a lot like Europe’s historically popular humorism, which was based on the idea of balancing the four humors (blood, yellow bile, black bile, phlegm). Needless to say, humorism was not only a pseudoscience, but also eventually actively disproved with the advent of germ theory and modern medicine. Cupping therapy is not more scientifically based than humorism.

On the placebo side of things, there probably is a little more to it than that; much like with acupuncture, a lot of it may be a combination of placebo and using counter-irritation, a nerve-tricking method to use pain to reduce pain (much like pressing with one’s nail next to an insect bite).

Here’s one of the few studies we found that’s in what looks, at a glance, to be a reputable journal:

Cupping therapy and chronic back pain: systematic review and meta-analysis

It may help by improving circulation and stimulating the immune system: True or False?

True! It will improve local circulation by forcing blood into the area, and stimulate the immune system by giving it a perceived threat to fight.

Again, this can be achieved by many other means; acupuncture (or just “dry needling”, which is similar but without the traditional lore), a cold shower, and/or exercise (and for that matter, sex—which combines exercise, physiological arousal, and usually also foreign bodies to respond to) are all options that can improve circulation and stimulate the immune system.

You can read more about using some of these sorts of tricks for improving health in very well-evidenced, robustly scientific ways here:

The Stress Prescription (Against Aging!)

Take care!