Aug 26 2011

Acupuncture and Acoustic Waves

Here is yet another study claiming to show “how acupuncture works” when in fact it does nothing of the kind. The bias of the researchers is so obvious in this study it’s astounding that it was published in a peer-reviewed journal. Of course, the mainstream media is dutifully reporting the biased claims of the researchers without any independent verification or analysis.

There are numerous fatal problems with this study. The first, like in many physiological studies that purport to be about acupuncture, is that the connection to acupuncture is tenuous. The researchers claim that they are testing the effects of an acupuncture needle – but what makes a needle an acupuncture needle? Other such studies were ultimately just seeing the effects of local tissue trauma. The fact that this trauma was induced by an “acupuncture needle” is not necessarily relevant.

This study is far worse, because it is simply using the acupuncture needle as a mechanism for inducing an unrelated physiological stimulus. This is similar to “electroacupuncture” where electrical current is applied through an acupuncture needle – what you are actually studying is the effects of electricity, not “acupuncture.”

This is the most significant fatal flaw of this study. What the researchers did was use an”acupuncture needle” (i.e. a needle) to apply a mechanical vibration (through a piezoelectrical device – one that converts electricity to mechanical force, or vice versa)  to the tissue. They justify this procedure by likening the vibration to manual manipulation that acupuncturists will do to the needle after insertion.

However – they were vibrating the needle at up to 50 hz – 50 times per second. There own data shows that lower frequencies have no physiological effect. Essentially the researchers were measuring acoustic shear waves (ASW) – in the tissue in response to this vibration. This is less than shocking – vibrational waves in tissue in response to vibration. Wow. But they also measured the release of calcium by the cells. They argue that the ASW cause the local cells to release calcium which then in turns triggers the release of endorphins – and that’s how acupuncture works.

What they actually showed, if anything, is that acupuncture does not work through this mechanism. They proved the opposite of what they claim, because their own data shows that the calcium release is present at 40hz, it is barely present at 20hz, and completely absent at 10hz and 5hz. So, to be generous, unless the acupuncturist is continuously vibrating the needle at 20 times per second, the physiological mechanism they are seeing is not relevant. It’s impossible, using just your hands, to vibrate a needle at 20hz. Further – acupuncturists don’t vibrate the needle, they may twist them or move them up and down, but not at anything approaching 20hz. The authors themselves state:

In studying acupuncture, an important and frequently overlooked procedure is the manual needle manipulation performed by acupuncturists after needle insertion. The needle manipulations are typically a series of rapid bidirectional rotation or up-and-down piston movements.

The authors failed in the most basic sense to demonstrate that their physiological model is at all relevant to acupuncture; they failed to note the relevance of the frequency of the vibrations they were using or the plausibility that this relates to the “rapid” movements of the needle that acupuncturists sometimes make.

The study also looked at the acoustic waves themselves and claim that they were more pronounced when the needle was inserted at an acupuncture point than when at a non-acupoint. I find this result frankly unbelievable. A review of the research does not support the notion that acupuncture points or meridians exist. Further, the clinical research shows that there is no difference in effect between needling acupuncture points or non-points (sham vs “true” acupuncture). About this the authors write:

Along with it is a system of tracks called meridians by the practitioners but invisible anatomically.

By “invisible anatomically” they mean – there is no evidence they exist. Meridians are the floating, invisible heatless dragons of Carl Sagan.

The fact that these researchers found results that depend on the existence of acupuncture points seriously calls into question their methods. Their results should be viewed  as the equivalent of N-rays or Bem’s future cognition results – likely artifacts of sloppy research and researcher bias.

It should also be noted that this study did not even look at clinical effects from acupuncture, so they were unable to correlate any of the physiological parameters they were looking at with any putative effect. Therefore there are good reasons for thinking the effects they are seeing are not relevant to acupuncture, and the researchers provide no evidence that they are.

The flaws outlined above are enough to render this study useless as support for acupuncture, but I think it’s also worthwhile to consider the bias of the researchers. I usually don’t spend time doing this, but there are a few points worth making with respect to this study. This study comes out of Hong Kong. There is a Columbia University author, but he is a non-MD electrical engineer who provided only technical assistance, and is not a medical researcher. This is relevant because a prior review of acupuncture research published in 1998 showed that 100% of the acupuncture studies coming out of Hong Kong (and several Asian countries) were positive. This is in stark contrast to acupuncture studies from the West or overall.

The most reasonable conclusion to draw from this is that there is extreme researcher and/or publication bias in these countries. Proponents might argue that Asian researchers know how to do acupuncture properly, but that explanation is not credible, and doesn’t apply to physiological studies like the current one.

I also note that one of the lead authors, Siu Kam Lam, was convicted of stealing 3.8 million dollars in donations while in public office and served jail time for this crime. Facts like this are always difficult to deal with. Withholding this information from this article seems like an omission, as this might be relevant in putting the honesty of the researchers into context. But it can also be interpreted as poisoning the well. In any case – I see it as full disclosure, and the reader can make of it what they will.

I will also note that the authors, in their introduction, give a glowing review of acupuncture, and shamelessly cherry pick the evidence to make it seem as if there is good published support for acupuncture. The opposite is true – systematic reviews show that there is no specific effect from acupuncture. It is nothing more than a ritualized placebo.


There is no evidence for any of the underlying claims of acupuncture – not even the existence of acupuncture points. The clinical research shows that acupuncture does not work – in order words, that it does not matter where or even if you stick the needles. Acupuncture is a placebo treatment.

Acupuncture proponents, however, continue to study the non-specific local physiological effects of sticking needles into tissue, and often even producing a physiological stimulus through the needle that has nothing to do with how acupuncture is practiced. They then claim that “finally” they have discovered how acupuncture works.

This current study is no exception. But interestingly, this study may be the first that actually proved that they found a mechanism by which acupuncture cannot work. The effect they found was only present when the needle was vibrated at 20hz or more – something which is not done and seems impossible for the acupuncturist to achieve.

12 responses so far

12 thoughts on “Acupuncture and Acoustic Waves”

  1. banyan says:

    That is some sloppy reasoning in analyzing the meaning of their results, but I suppose the results are real. Could it have been published because the editors thought there might be something important in the data unrelated to acupuncture?

    Incidentally, because I am a law student, I became curious and looked up Law Review articles on alternative medicine. Law Review articles tend to be all analysis and opinion, and are therefore highly susceptible to bias. What I found is that most Law Review articles on the topic are entirely credulous. At least one cavalierly uses the term “allopathic” without ever explaining where the word comes from. One uses the scientific community’s rejection of alternative medicine as evidence that the whole notion of objective science is questionable (arguing that scientific questions should be in the hands of juries).

    Law Reviews often become the citation fodder used by lawyers and judges in forming new policy, so the phenomenon might be worth looking into.

  2. locutusbrg says:

    I find your comment the most disturbing thing I have read about sham medicine in this blog. I have felt for quite a while that the courts are the only official body of the government that has any scientific rigor at all. Given the traditional failure of creationism, intelligent design et Al. in the courts. It was the one area I thought science had any chance of traction. Very very depressing.

    Does anyone else fell that your are standing at the bottom of a waterfall trying to swim upstream?

  3. TylerR says:

    I agree with you there, locotusbrg. Wow, I didn’t expect how much “science by jury” would upset me.

    Steve, as always I love your breakdowns of acupuncture studies. Each time they play a new game with the results and it’s always interesting/funny/sad to see their work dissected so thoroughly. I have a fondness for this as I was introduced to applying scientific critical thinking to pseudoscience by a great endocrinology professor who would assign midnight miracle-cure commercials as homework. The activity is so much fun and I am always surprised at how much there is to learn about the scientific process itself. Acupuncture studies seem particularly suited as there could be an actual effect from a needle going through skin, but how well blinded is the study? Is the statistical analysis mining the data too far? Do the controls actually control for the experiment? By the time the issue is ferreted out, we’ve all had a great review of the basics and how easy it is for even good scientists to forget them.

    By the way, that’s my favorite opening line to any of your blog posts.

  4. tmac57 says:

    Well,I came to a different conclusion after reading your article:
    Asian acupuncturists possess magical super powers similar to the Flash,that western ones don’t.It seems so obvious.

  5. daedalus2u says:

    This is interesting, not as an explanation of acupuncture but of the effects of mechanical shear on tissues. A general effect of shear is to activate nitric oxide synthase and release NO.

    That is the mechanism for regulation of blood pressure, shear at the vessel wall activates eNOS, generates NO and causes dilatation until the shear matches the setpoint.

    Shear in fluid in the voids in bone is the mechanism for activating NOS on bone strain which generates NO and regulates deposition of bone mineral at sites with the highest NO which have the highest strain.

    Whole body oscillation causes increases in whole body NO levels.

    A hypothesis I have for the peripheral neuropathy that accompanies long term work-related vibration exposure is that the vibration does increase the local NO level, but then physiology compensates by removing that excess NO via inflammation and generation of superoxide. When the vibration is no longer present, then the NO level is too low and the nerves don’t work properly. The time constant for the regulation of the NO/superoxide balance isn’t fast enough to compensate.

    The other problem is that the low NO state has hysteresis and is difficult to get back to the normal high NO state without the normal exogenous source of NO from skin bacteria which generate NO from sweat. Hands and paws have a very high density of sweat glands.

    Low NO could be a final common pathway in a number of peripheral neuropathies, diabetic neuropathy and those associated with vascular and wound healing deficits (low NO causes those symptoms too).

    What this means for acupuncture, if this is the mechanism, then acupuncture could have side effects like those from vibration induced injury. It also means the needle isn’t necessary, breaking the skin isn’t necessary, the meridians are not necessary and another and better regulated source of NO would work better (like my bacteria 😉 ).

  6. rezistnzisfutl says:

    What I find most disturbing is that another quack study was posted in a scientific journal. It doesn’t help to inspire confidence or trust in the peer-review process, something I think is critical in science if it’s going to maintain its integrity. I realize no system is perfect, but things like this give too much credence to quack/woo proponents and reduces confidence in actual science, which is already under enough criticism as it is (whether it’s warranted or not, public opinion on the scientific disciplines seems to be waning).

  7. banyan says:

    @Locutusborg: To clarify, Law Review articles are not necessarily representative of what will be decided by courts. They are one source of persuasive authority. They can, however, steer scholarly opinion in a very slow and indirect way, especially if they repeatedly come out the same way on some issue.

    I found the articles by a search for “regulation of homeopathy” on Westlaw (a legal research tool) under Law Reviews and Journals. Here are some notable results, so you can see what sorts of things law professors are arguing for:

    Michael H. Cohen, Holistic Health Care: Including Alternative and Complementary Medicine in Insurance and Regulatory Schemes, 38 Ariz. L. Rev. 83 (Spring, 1996) (a credulous article coming from my own Law Review, I’m afraid);
    Lori B. Andrews, The Shadow Health Care System: Regulation of Alternative Health Care Providers, 32 Hous. L. Rev. 1273 (1996) (also credulous, arguing for relaxing regulatory standards to allow greater access to CAM);
    Barbara L. Atwell, Mainstreaming Complementary and Alternative Medicine in the Face of Uncertainty, 72 UMKC L. Rev. 593 (2004) (including the following quote: “Given the fact that some conventional medical treatments are of questionable efficacy, it is inappropriate for health insurers to deny coverage for CAM treatments because their effectiveness is also uncertain at times.”).

    There are many more along the same vein. Looking at the results again, I think it’s fair to say that the overwhelming majority of Law Review articles I’m finding are credulous. Then there is the worst article, which I mentioned before as arguing that juries should decide scientific questions. Michael S. Jacobs, Testing the Assumptions Underlying the Debate About Scientific Evidence: A Closer Look at Juror “Incompetence” and Scientific “Objectivity,” 25 Conn. L. Rev. 1083 (1993).

    I did find one article by an author apparently familiar with the skeptical literature. Patrick L. Sheldon, The Truth About Homeopathy: A Discussion of the Practice and the Dangers That Inhere, 8 Quinnipiac Health L.J. 289 (2005).

    This isn’t something to freak out about. The proper response I think would be for a skeptical scientists, maybe someone from SBM, to co-author an article with a law professor or practitioner mainly explaining why legal professionals lack the necessary expertise to deal with these issues and present an “alternative” viewpoint on how legal professionals can contribute.

  8. PharmD28 says:

    I work at a VA medical center….at my facility, one of the MD’s will be performing acupuncture. Wondering why would VA pay someone to do this with tax dollars?? As a clinical pharmacists we are big stewards of evidence based medicine to save money for the VA and taxpayers…this seems like the wrong direction….wondering if myself or others will start to question this stuff in some way shape or form..

  9. Nitpicking says:

    Steve, I presume you wrote to the European Journal of Physiology (if I have deduced the correct journal) to make these same points? As a Yale professor your voice actually has weight.

    Stay safe in the hurricane.

  10. ccrome says:

    Maybe they should try 5 to 9 Hz ( and see what happens 😉

  11. jaranath says:

    I’d add a couple of minor caveats to this one. Everything Steve said is correct, but as with electro-acupuncture, the non-acupuncture parts of the technique might still have some validity. Irrelevant to acupuncture and meridians and such, but possible. How much more could we learn, I wonder, if the authors had honestly been trying to discover new mechanisms for local pain relief, rather than dishonestly trying to find the mechanism for a phantom therapy?

    Also, I would bet you technically CAN vibrate an inserted needle at 20hz by hand. It just won’t be comparable to the way the authors did it. I could easily imaging that rubbing, scratching, tapping, releasing (a sort of “twang” effect) and otherwise handling a needle will generate a wild range of unstable, shifting frequencies…basically noise, as with handling any object…some more than others… I’m sure those frequencies would often swing through that 20-50hz range. But the amount of real time spent at those frequencies would be very small, and they would occur randomly, and the volume would vary, and…you get the idea.

    No, it’s not comparable in any useful way to what the authors did. But watch for one of them pointing out that you can SO make a needle vibrate at a few dozen hertz by hand, which proves unequivocally that their proven placebo works by not being a placebo!

  12. Sonja L says:

    I actually was subjected to this. I had a sore back and went to see a masseur recommended by my son’s Occupational Therapist. After a nice rubdown on my shoulders, while lying on my stomach, he started to place those little needles in me. I said I didn’t want acupuncture. He suggested it would be soothing. Being a skeptic for some time, I doubted his statement, but thought – “What the heck, I’m here. Let’s give it a try and at least I’ll have some actual data to back my belief that it’s phoney-baloney.” I did not realize, until he turned on a switch, that I was also rigged to a machine for this vibration therapy.

    He then left me alone in a dark room being hit with little surges of electricity at measured spaces while he apparently went out for a smoke (he stunk of tobacco upon returning).

    Something must’ve been glitchy with the machine because shortly after he left, the electricity would surge and “hold” my back muscles in a rigid state that was quite painful. I was also getting a mild shock. I shouted for help (and for longer than I wished) before he returned and turned off the juice. My massage was ruined, he claimed this had never happened before and would not give me a refund or even deduct from the $110 fee for my pain.

    While he was pulling the little needles out of my back, his wife/biz partner was attempting to sell me on purchasing her services for “Spiritual Counseling” (after my trauma, I must’ve appeared to need it) and my favorite, “Cellular Memory Work”. I still have no idea what that was supposed to do for me, but let her know that I was not that interested right at the moment.

    I later checked his “creds” online (should’ve done it before going – I know, I know – but I trusted my son’s OT) and discovered that our state does “credential” acupuncturists. This guy was less than a month away from having his credential lapse. I guess he needed my $110 to pay the fee.

    I complained afterward to the state and it didn’t mean anything since it’s such a goofy and unregulated “regulated” business. Claims of study in China are difficult to verify. How do you know if the person passed/failed whatever if the license is written in Chinese characters and looks as if it could be purchased in a back alley calligraphy shop.

    Chalk it up to “learning the hard way” and “adventures in quack medicine”.

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