A few years ago, I found myself on a small boat in the Pacific Ocean. The weather conditions were dodgy, but our skipper decided to go ahead with the whale watching expedition. The first couple of big waves were actually fun, but very quickly my brain and my gut decided that they weren’t fun anymore. A boat, they concluded, is supposed to move horizontally on a body of water, not vertically. Thus began one of the worst days of my life. I vomited not just once but twice and spent hours on the deck of the boat, getting thoroughly soaked and feeling like I just needed to get off. The weather was so bad, even the whales decided not to show up.
Some people will argue that my torment could have been prevented by the wise use of my wrists. There is a spot on the wrist that, when pressed, is alleged to stop nausea in its tracks. Specialty bracelets, like Sea-Band, can be purchased for this purpose: their stretchable band has a plastic dome stitched on the inside and the dome’s pressure on the wrist is said to do the trick. There are even expensive electronic bracelets that will stimulate this spot with the right vibrations. Sure, drugs exist that claim to relieve nausea, but they don’t always work well and many cause drowsiness. A bit of pressure on the wrist sounds nicer.
It is easy to find a slew of scientific studies apparently confirming that there is an on/off switch for nausea on the wrist, but digging into this literature requires layers of interpretation.
The first layer is that the nausea spot on the wrist is an acupuncture point.
A brief history of acupuncture
Acupuncture received a makeover in the last fifty years or so, a public relations facelift that obscured its limp foundation and made it look professional and respectable. But as the Australian health advocacy group Friends of Science in Medicine summarized in a fantastic article, Traditional Chinese Medicine, of which acupuncture is a branch, is “one of the major pre-scientific medicines.” In the days before the systematic development of the scientific method and well before the advent of clinical trials to help separate the medical wheat from the chaff, diseases were seen as imbalances and blockages in imaginary life forces, and interventions like acupuncture were meant to restore their flow. Acupuncture in those early days bore little resemblance to the modern practice: needles were not hollow and painful areas were lanced. It was essentially a form of bloodletting.
As so-called Western medicine moved away from the notion of humours and embraced scientific inquiry in the 19th century, China followed suit. The teaching of acupuncture was banned by China’s Imperial Medical Academy in 1882 and the use of the technique was itself banned in 1929. But peasants outside the big cities needed access to medical care, and Chairman Mao Zedong was intent on nurturing Chinese national pride, and so the 1960s saw him revive traditional Chinese medical practices, including acupuncture, as part of a comprehensive manual to teach the “barefoot doctors” of the countryside some form of healthcare. Famously, Mao himself did not believe in these pre-scientific interventions. He confessed as much to one of his personal physicians, who had been trained in conventional medicine: “Even though I believe we should promote Chinese medicine,” Mao said, “I personally do not believe in it. I don’t take Chinese medicine.” His public endorsement of acupuncture was political propaganda.
The edifice of acupuncture continues to crumble as we poke its support beams. Its central life force, called Qi (pronounced “tchee”), exists outside our large body of scientific knowledge. We may as well go looking for the soul with our microscopes. The meridians that supposedly connect distant parts of our body and in which Qi flows were modelled not after actual anatomy, but possibly after the idea that the human body must be similar to nature, and nature has rivers. And the number and location of acupuncture points vary widely from one practice to another. Over 2,000 have now been described and it is becoming harder to find an inch of skin on the body that has not been identified as an acupoint.
Studies have revealed that toothpicks can “work” as well as acupuncture needles for low back pain. Performing acupuncture on a rubber arm your brain has been conditioned to think as your own can also yield the same experience as needles in skin, which makes one wonder if acupuncture is all in the mind. And perhaps because of cultural bias, virtually all acupuncture trials coming out of China, Japan, Hong Kong and Taiwan just happen to show that those tiny needles really work. This doesn’t smell right.
Thus, the fact that nausea’s “power off” button on the wrist belongs to this pre-scientific belief system that has been pummelled by science should give us pause, but I will argue that one can stumble upon truth by trial and error even if one’s beliefs are incorrect. It is possible that the broken clock of acupuncture happens to be right on the topic of nausea, that pressure on the wrist somehow triggers a détente of the brain’s vomiting centre.
This wrist acupoint is known by various names: the Nie-Guan point, pericardium 6 or, more commonly, P6. Look for the skin crease that denotes where your palm ends and your wrist begins, and go down the wrist two to three fingers’ width, and you will have found P6.
Does pressing on P6 make nausea go away?
Squinting through a dirty window
There are many, many studies of acupressure for nausea and vomiting. They are accompanied by an impressive array of review articles, clinical guidelines, systematic reviews, and meta-analyses. Basically, the topic has been thoroughly investigated; and yet, the seesaw movement of the evidence—here positive, there negative—from one review article to the next is bound to make the reader nauseous.
A review will suggest that studies show acupressure to be ineffective against nausea and vomiting, but another will conclude that it works for nausea but not for vomiting. The acupressure wristbands mentioned earlier do not appear to work when nausea is provoked via spinning someone on a “seasick chair.” This was even tested on Mythbusters: the bands did nothing. Meanwhile, a Cochrane Collaboration review published in 2012 reported that acupressure does appear to work for the nausea felt during a C-section under anesthesia but not for the nausea that appears after delivery or for the vomiting itself. An updated version of this review was just published and the conclusion has changed: for nausea, the evidence is uncertain, whereas it may reduce vomiting. The evidence was qualified as either low or very low certainty, so it’s a little bit like trying to guess who is standing outside a window that hasn’t been washed in a century. Professor Edzard Ernst, who specializes in the critical appraisal of the literature on complementary and alternative medicine, has summed up this seesawing body of evidence as “contradictory to a degree that is baffling.”
There are many reasons for these contradictions. The studies vary widely. Some ask their participants to stimulate P6 for two and a half minutes; others, for 24 hours. Some studies use acupressure, while others whip out needles, lasers, and even electrical stimulation of the needles, all under the generous umbrella of “acupuncture.” Many studies focus on postoperative nausea and vomiting, but others look at pregnancy-associated nausea or the nausea that comes from chemotherapy. But even in the latter, there is anticipatory nausea (in the week preceding the chemotherapy), acute nausea (within 24 hours of receiving the treatment), and delayed nausea (in the six days following chemo). This heterogeneity among the studies has led some researchers to quash their hope of analyzing all of these studies together, as it would be a case of comparing apples to oranges.
A large number of studies on acupressure and nausea are also simply poorly done. They lack a proper control group (or a control group altogether), their blinding is poorly reported (or poorly done), and the determination of what exactly makes for a good placebo control has invited many different answers, from wristbands without the plastic dome to acupressure on an unrelated part of the body. Some have also pointed out that people who do not believe in acupuncture are unlikely to enrol in an acupuncture or acupressure clinical trial. If acupuncture’s power lies in suggesting to people that it is working, trials will be left with participants likely to claim improvement, regardless of objective facts.
All of this unremarkable evidence which trends toward positivity deserves one more asterisk. The authors of a 2006 meta-analysis of the overall evidence pointed out that, even though P6 was the most commonly used acupressure location, the literature contained at least 20 others, which were “just as effective as P6 and sometimes more so.” That’s a lot of body parts that can be pressed to stop nausea in a pinch. Meanwhile, a 1963 book written by the president of the Medical Acupuncture Society ties the P6 acupressure point to not just nausea, but to heart and lung inflammation, heart disease, palpitations, ulcers, and nerve pain. It beggars belief that pressure on the wrist can have such wide-ranging and effective action.
So does acupressure of the P6 point consistently work to relieve nausea? I reached out to Timothy Caulfield, Canada Research Chair in Health Law and Policy at the University of Alberta, denouncer of pseudoscience, and motion sickness sufferer. His sense is that out of this mass of often contradictory studies emerge “signals toward some degree of modest efficacy.” Maybe it works, although many studies using sham acupressure bracelets show them to be as efficacious as the real ones. But if nausea is a bother, these anti-nausea wristbands are pretty cheap and safe (apart from some irritation and soreness where they press on the skin), so this is an intervention with few barriers to entry. When I asked Caulfield if he had tried the anti-nausea bands himself, he told me he had but that they had not worked.
Interestingly, though, the claim that acupressure can relieve nausea is usually held up, Caulfield wrote to me, as a significant victory, “the mic drop example of an alternative medicine procedure that really works.” But the evidence is mixed and suggests small benefits for a very specific condition. “That should tell you something about the state of acupuncture and alternative medicine more broadly.”
If acupressure against nausea does work, and I am not convinced that it does, it is certainly not because of mystical energy flowing down bodily rivers. And if this is the best evidence we have for the overall benefits of acupuncture—a pre-scientific attempt at formulating an explanation for all of our ills and at crafting a one-size-fits-all-diseases solution—it certainly throws the whole practice into sharp relief, and not in a good way.
-Some people believe that applying pressure on the wrist at the acupressure point known as P6 can relieve nausea and prevent vomiting
-The scientific evidence behind this claim is wildly contradictory, though it overall suggests that maybe it can work a little bit
-Studies of acupressure for nausea are often of low quality; they vary a lot, making comparisons between them difficult; and they are testing a pre-scientific belief system that claims that blockages in the flow of a mysterious life force down imaginary rivers in our bodies can be relieved by needling or pressure
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