A biological basis for acupuncture, or more evidence for a placebo effect?

By Ed Yong | May 30, 2010 1:00 pm


In the past, I have criticised science journalists for not providing enough background in their reports. Both news stories and scientific papers obviously focus on new events and achievements, but they do so in the knowledge that new discoveries stand on giant shoulders. For this reason, when I cover new papers for this blog, I try to describe some of the research that led up to it, a tactic that fits with the growing cries for more context in modern journalism.

And yet, it’s perhaps churlish to expect this to be a routine part of science journalism when many scientists themselves don’t take up the practice. I bring this up in the light of a new paper, published today in Nature Neuroscience, about the controversial topic of acupuncture. I was going to do this as a straight write-up but actually the omissions in the paper are probably just as interesting than the science within it.

The gist is this: Nanna Goldman from the University of Rochester Medical Center claims to have found a biological explanation for the pain-relieving effects of acupuncture. She worked with mice that had inflamed paws, and managed to alleviate their pain by using a needle to pierce a traditional acupuncture point near the knee. This painkilling effect only happened when she rotated the needles after insertion.

This effect depended on a chemical called adenosine, which typically surges in concentration after any stress or injury. Adenosine works by docking at a protein called the adenosine A1 receptor, which has well established roles in suppressing pain and is found on neurons that transmit pain signals. Indeed, other chemicals that stimulated this protein had the same pain-relieving effects as acupuncture. Drugs that prevent the body from breaking down adenosine led to even more potent pain relief. And mice that lacked the A1 receptor altogether experienced no pain relief from the needles.

Taken on its own merits, this is a nice piece of biochemistry. But what does it really tell us about acupuncture? Does it actually validate this ancient method as a way of relieving pain? After reading the paper, you might walk away with that idea that we’re one step closer to understanding how a treatment with real medical benefits really works. It’s littered with statements like “A1 receptor activation is both necessary and sufficient for the clinical benefits of acupuncture” and “medications that interfere with A1 recep­tors or adenosine metabolism may improve the clinical benefit of acupuncture”. In the study’s press release, lead scientist Maiken Nedergaard even says, “The new findings add to the scientific heft underlying acupuncture.”

But these results have to be considered in the light of those that came before it. As mentioned above, new scientific discoveries stand on the shoulders of giants and in the case of acupuncture – one of the most well-researched of all “alternative therapies” – those shoulders are particularly large.

Many trials have demonstrated that acupuncture does have some pain-relieving effects – that is not in doubt. And as Steven Novella notes, unlike things like homeopathy or reiki, with acupuncture “something physical is actually happening… so it is therefore not impossible that a physiological response is happening”. But the big questions are whether this effect is genuine of nothing more than a placebo.

To answer that, clinical trials have used sophisticated methods, including “sham needles”, where the needle’s point retracts back into the shaft like the blade of a movie knife. It never breaks the skin, but patients can’t tell the difference from a real, penetrating needle. Last year, one such trial (which was widely misreported) found that acupuncture does help to relieve chronic back pain and outperformed “usual care”. However, it didn’t matter whether the needles actually pierce the skin, because sham needles were just as effective. Nor did it matter where the needles were placed, contrary to what acupuncturists would have us believe.

Other trials have found similar results. Going beyond individual studies and looking at all of the available evidence doesn’t much change the verdict. Last year, scientists from the Nordic Cochrane review centre did an analysis of the available evidence and after considering the 13 trials that met their stringent quality criteria, they concluded:

“A small analgesic effect of acupuncture was found, which seems to lack clinical relevance and cannot be clearly distinguished from bias… Our findings question both the traditional foundation of acupuncture, which is based on the existence of meridians and Qi sensations, and the prevailing hypothesis that acupuncture has an important effect on pain in general. If this hypothesis is wrong, and our results point to that, then acupuncture would seem to be unlikely to have an effect on pain related only to certain conditions, but further studies may examine this question.”

Goldman doesn’t really address any of these points. The introduction to her paper focuses on acupuncture’s popularity, mentioning endorsements by the WHO, the NIH and, strangely, the US Internal Revenue Service. As to the bigger question about whether it is effective, there is no sign of the recent trials or reviews that I mentioned. Instead, she briefly says that the pain-killing effects of acupuncture are “well-documented” and that “Western medicine has treated acupuncture with considerable skepticism”, citing only an editorial published in 1972.

As I’ve said, this is not an area that’s lacking in earlier research to refer to or consider. The discussion is a bit better in that it at least references one trial which showed that acupuncture has no advantage over placebo sham-needle treatments. And if anything, the results seem entirely consistent with the idea of acupuncture as an elaborate placebo.

The tissue damage inflicted by the rotating needle triggers a local flood of adenosine. If the needle is stuck in the right general area, the extra adenosine reaches the receptors on the pain-transmitting neurons and shuts down their activity. There is no need to invoke ‘qi’ flowing through ‘meridians’. Indeed, all sorts of injuries and stresses will lead to a burst of adenosine. And Goldman even says that sham needles, by stimulating but not breaking the skin, could still trigger a burst of adenosine, leading to the same pain-killing effects.

There has been so much previous work in this area that the question “How does acupuncture work?” is better replaced by “Why are acupuncture’s effects largely indistinguishable from those of sham treatments?” The new study suggests some answers but it seems unfortunate to me that Goldman didn’t include any sham-needle controls in her experiments.

Brian Berman, who has been involved in previous Cochrane reviews of acupuncture, agrees. He described the study a “very interesting” but said that “some sort of a placebo control is needed”.  Edzard Ernst, former professor of complementary medicine at the University of Exeter, has written extensively about acupuncture also concurs. He told me, “It’s an interesting study but it proves nothing. We need independent replication, better controls and studies in humans.”

This is the most frustrating part of what could have been a really fascinating study. Without building on the massive amount of work that’s already been done on acupuncture, it is hard to know what to make the new and admittedly interesting results. I also wonder whether your average health journalist will know how this study fits into the bigger picture – whether it vindicates the use of acupuncture or whether it actually fits with a skeptical stance. But I suspect we won’t have to wait long to find out.

PS: The paper notes that the authors have no competing financial interests that might have affected their work. However, it is worth noting that one of the co-authors, Jurgen Schnermann, is married to one Josephine Briggs. Briggs is the director of the National Center for Complementary and Alternative Medicine, an institute that has had its fair share of controversy in the past.

Update: Yeah, the mainstream media aren’t really covering themselves in glory here. See Stuff and Nonsense for a summary. The Times probably has the best piece, in that it actually mentions previous trial data and has some great commentary from Edzard Ernst.

Reference: Nature Neuroscience http://dx.doi.org/10.1038/nn.2562

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Comments (59)

  1. Fascinating analysis, Ed! You never cease to amaze :)

  2. Rocky

    You are criticizing biochemists for not going outside their field to take into account the entire history of acupuncture research in order to put their research into context. You are criticizing the researchers for not testing sham acupuncture at the same time they tested traditional acupuncture.

    Scientists rarely put their research into broader contexts, choosing to focus on what they really understand.

    Science works in small, incremental steps. One reasonably obvious next step is for these researchers (or perhaps others) to test sham acupuncture.

    Why pick on this particular paper? You have tens of thousands to choose from!

  3. Al

    That PS kinda nails it, doesn’t it?

  4. Ed Yong

    I’m well aware that science progresses in small incremental steps, but this is why context is important. One needs to bear in mind work that has gone before so one can ask the right questions. And I’m not convinced that this has been done in this case.

    As to why I’m writing about this paper: I found it interesting and irritating at the same time. And I wanted to analyse it in the context of existing research because I felt that (a) they hadn’t and (b) the mainstream media were unlikely to

  5. rodrigo

    Rocky: It does not seem at all unreasonable to ask the paper’s authors for context. This is not a study in some niche area of biochemistry. Is it obvious that the question itself was motivated by a social context in which acupunture has been theorized about. Why would it be reasonable to use that context to motivate your research, but then ignore it when presenting your results?

  6. I also think it’s important to answer the question of whether acupuncture works or not sooner rather than later – since public health dollars are now being spent on it in some Canadian provinces (British Columbia for sure; not sure in how many others) – and money to support our public healthcare system is being diverted largely from the education budget. In other cost-cutting measures, eye exams are no longer covered by the public healthcare system in that province (they used to be paid for every two years, despite the fact that ‘heavy’ computer users should probably have their eyes checked every year – and who isn’t a heavy computer user in 2010)?

  7. DK Fennell

    Ed: I am very dubious about acupuncture, although I know almost nothing of the research. That said, and the promise that I am really not trying to start a fight but rather to understand the point you are making, I am wondering how can a placebo effect work in mice? I am asking this because it seems to me that surely mice don’t “believe” that acupuncture is going to work. If the “painkilling effect” really “only happened when she rotated the needles after insertion,” as you report the paper says, then what is a placebo control going to be used for?

    I agree that the promotion of acupuncture by the authors even in the introduction bis out of line and the non-disclosure of the spouse’s interest is ethically suspect, whatever Nature Neuroscience’s disclosure rules are. (That seems to me, however, to go to whether it would be worthwhile to see if the result could be duplicated by someone without an interest in the result, before accepting the results on their face.) But I just don’t get how Berman would design a placebo control in mice in this context or what good talking about recent research in humans in this context does.

  8. Great piece, as always.
    But Ed,
    why do you really need “placebo” control in an animal trial?

  9. My thoughts on this are that acupunture is not a single thing, as Traditional Chinese Medicine assumes, but is actually different modalities.

    I wrote the “FAQ” on acupuncture for the sci.skeptic NNTP newsgroup years ago, and at that time I believe there was reasonable evidence for acupuncture analgesia above and beyond expectancy effects. I don’t know if the situation has changed significantly since then.

    Analgesia stood out however as the only effect that had such evidence, and the mechanism was not clear. Not all of the supporting studies seemed to show mediation of the effect via naloxone as I remember, so this Nat Neuro data may actually help to explain the non-opioid analgesia, so in that context it may have real scientific value.

    On the other hand, there are many things acupuncture is used for that are not analgesia, and as far as I know, no clear evidence for mechanisms for those beyond placebo, at least not any single overarching physiological theory. So, the claims of the article to have found “the mechanism” for acupuncture are ertainly dubious in the larger context.

  10. Trying to catch up my reading on acupuncture analgesia, I came across this 2008 article in Pain Medicine reviewing studies testing various hypotheses of central mechanisms of acupuncture analgesia.


    Now I realize very well that it is very problematic to distinguish centrally mediated opioid mechanisms of acupuncture from expectancy effects, so although I suspect there is something more than expectancy here, I won’t try to make that argument.

    However I do notice from reading between the lines here that they still recognize a non-opioid component to acupuncture analgesia, and this is where the Nature Neuroscience article might tell us something new.

    kind regards,


  11. phayes

    “I also think it’s important to answer the question of whether acupuncture works or not sooner rather than later ”

    It isn’t in the least important. Complex question fallacy: ‘Acupuncture’ works for what medical condition(s) exactly?

    It’s like the ‘Homeopathy’ crap. Are we supposed to test every possible substance in the entire chemical universe – from cincona bark to essence of shipwreck (all diluted out of existence of course) – and for all possible conditions, no matter how vaguely specified, which the homeopaths suggest they might (in substantial quantities) cause, before concluding that there was never any good reason to test *any* homeopathic nonsense ‘remedy’ in the first place?

    I think not.

    Why? Because neither ‘Acupuncture’ nor ‘Homeopathy’ exist as well motivated, well specified coherent and plausible ideas in the first place. Both pretend to be complete general ‘systems of medicine’ or highly condition specific particular interventions, depending on which question they are trying to evade at the time.

  12. I guess the placebo effects in mice issue would be best addressed by considering how they assessed pain relief in the mice. Placebos don’t just mean that people expect to feel better – as pointed out elsewhere, acupuncture involves physical stimulation and in humans, the effects of acupuncture do not differ from the results seen with sham needles that don’t break the skin (i.e. it is the tactile stimulation that has an effect). Pain is notoriously difficult to measure objectively in humans and in non humans other measures (avoidance, physiological stress responses) are typically reported. As far as I can see it is a physiological change being discussed in all the reports of this paper (i.e. adenosine levels) and as Ed says, there is no indication that a control (e.g. sham needles) has been included. The fact that rotation of the needles is important also seems to be attributed to the adenosine changes.

  13. G H Rosen

    Recently, in a different context (that is, the context of a very sore back), I browsed research on acupuncture and piriformis syndrome–a sciatic-pain problem. One study I found came from a Chinese source–an institution practicing clinical acupuncture, which obviously believes in the technique’s basic efficacy–where a comparison was made between acupuncture treatment for piriformis-muscle pain with and without rotation of the needles. Both techniques seemed to provide relief of symptoms, as compared to a control group, but the rotated needles provided relief with fewer treatments in a shorter period of time. This study, like the one in Nature Neuroscience–like any study–only shows what it shows. But it certainly suggests that there may be something to the adenosine theory deserving of more work. Certainly one can criticize science journalists for over-hyping stuff, but I don’t think any individual researcher is responsible for what journalists make of one study. And just as I’m suspicious of any overgeneralizing of one study, I’m suspicious of Ed Young’s overgeneralizing his criticism of the research design of specific studies into a glib dismissal of a whole topic of research. I’ve been reading–and sometime professionally editing–medical research for decades, and I’d suggest that playing the “placebo effect” card is often a lazy, knee-jerk substitute for actually analyzing a study’s methods and results. (And it can lead to really weird stuff like studies of “sham surgery” that are riddled with logical holes and, to me, are a huge waste of time, money, and the ethical capital of science.)

  14. Rita Wing

    Leaving the poor little buggers alone would be the best relief,though, wouldn’t it?

  15. Jack Smith

    I have recently had acupuncture. Perhaps it is because my acupuncturist merges Western and Eastern techniques and works on athletes for muscle strains, but several of the needle insertions do in fact cause muscle “jumps” and “ripple effects” of contraction and relaxation. I experienced soreness afterward — as if I had worked out — and the problem areas I wanted loosened up were in fact loosened up considerably. So it does matter where the pins are placed if the acupuncturist is targeting a particular muscle group where there has been high tension and low blood circulation. The skepticism of the author tends to suggest that he has never had acupuncture, but the argument he is making is akin to arguing a hot stone treatment (having hot stones rubbed against tight or sore muscles) cannot possibly improve circulation or reduce stress. It’s just silly.

  16. QUOTE:
    “The paper notes that the authors have no competing financial interests that might have affected their work. However, it is worth noting that one of the co-authors, Jurgen Schnermann, is married to one Josephine Briggs. Briggs is the director of the National Center for Complementary and Alternative Medicine, an institute that has had its fair share of controversy in the past.”

    Not to worry. That must just be a placebo financial conflict.

  17. DK and Daniel – Sophie (#12) has answered the question about placebos better than I could have. The possibility of a placebo is one issue here. The other is that any effect could be a very general one that’s common to pretty much anything that would traumatise tissue. As I’ve said, it’s very likely that stabbing the body with needles produces some physiological effect. But what’s in dispute is whether the details of acupuncture – i.e. placing needles at very specific points to manipulate the flow of qi down meridians – is actually valid. And the answer from trial data suggests that it’s not.

    Jack Smith – I actually have experienced acupuncture at the hands of two separate acupuncturists for a shoulder injury around a decade ago. But I know well enough that my own personal experience is completely irrelevant here when it comes to addressing whether this technique actually works. This is why we have randomised clinical trials.

  18. phil

    Good job, Ed !

  19. Jason Lester

    The “sham needle” study is interesting, but also shows the researchers lack of knowledge concerning acupuncture theory, as both acupoint and acupressure involve the stimulation of pressure points without actually piercing the skin. In fact, there are a kind of acupuncture needle called Teishin needles which are not intended to puncture the skin, and seem to not be substantially different than the “sham needle.” As such, the “sham needle” would not be recognized by the TCM community as a true control – rather, the efficacy of the “sham needle” would seem to confirm that both acupuncture – which requires a license and board certification – and acupressure, which does not, are both viable treatment options.

    The more interesting part of the study for me is that the actual point of insertion (or non-insertion) didn’t seem to matter. This certainly deserves further investigation.

  20. Jack Smith

    But I know well enough that my own personal experience is completely irrelevant here when it comes to addressing whether this technique actually works. This is why we have randomised clinical trials.

    No, that is not true. The technique works on some people. The question is whether the technique can be shown to work across various persons in a reliable manner under experimental conditions. If someone stabs one of your muscles with a pin and it causes a reflexive spasm throughout the entire muscle group, that just happened. You do not need a double-blind randomized clinical trial to prove that it happened.

  21. Dan

    “The technique works on some people.”

    So does a Placebo!

  22. Adela

    And this is why when as a kid when I skinned my knee I would bite my knuckle. Same effect. I don’t need to pay some one to do this when I can stimulate my own adenosine.

  23. O'DB

    Interesting piece Ed. Thanks.

    On a broader sweep, it got me thinking about the placebo effect. I know this isn’t an original thought, but assuming that the placebo effect is significant in pain relief, then isn’t this a valid piece of a medical practitioner’s arsenal for treating patients? Or, in other words, is it right, ethically or Hippocratically, for a Dr. to knowingly defraud their patients with whatever works (yes, even homeopathy if the patient believes it works) to elicit a placebo effect? I’m not pro-alternative remedies, but if the placebo is a sufficiently strong effect isn’t it worth deliberately eliciting this response if it helps?

  24. @ O’DB #23

    I’m not a doctor, but I have been a patient. The thing is, you can get a very strong placebo effect just from having a doctor talk to you or touch you. That kind of placebo is fine, as is having a doctor reassure you that you’re going to be OK. If doctors only prescribe actual effective treatments, then you get a strong placebo plus real medicine. BTW, I got this idea from a book about placebos, but I unfortunately can’t remember the name of either the book or the author. There are over a thousand books on ‘placebo effect’ on Amazon!

    On the other hand, plugging in ‘sham treatment’ pulled up several books on acupuncture. Just sayin’.

  25. Jack Smith

    So does a Placebo!

    Right, except I’m not referring simply to needle insertion, but needle insertion to stimulate muscle contraction or relaxation. That is quite different than simply piercing the body all over (without doing any muscle work), and my point is that you do not need a double-blind study to tell you that you just experienced muscle spasms. Many acupuncturists treat athletes for muscle strains and sports injuries — focusing on that self-selected group would determine the physiological effect of acupuncture, not taking in random members of the general population (who may receive no benefit, or no benefit greater than a placebo, because they don’t need it).

  26. phayes

    “That is quite different than simply piercing the body all over (without doing any muscle work), and my point is that you do not need a double-blind study to tell you that you just experienced muscle spasms.”

    That’s true – it’s an interaction simple enough and an effect size large enough to make such studies unnecessary. But so what? The detection of a muscle spasm is not evidence of a clinically desirable outcome in the case of muscle strain any more than the sight of a drop of blood is evidence of a successful vaccination injection.

  27. Dan

    ““That is quite different than simply piercing the body all over (without doing any muscle work), and my point is that you do not need a double-blind study to tell you that you just experienced muscle spasms.”
    True, but as phayes also said, “The detection of a muscle spasm is not evidence of a clinically desirable outcome,” which is precisely my point. You can convince yourself that you feel better and/or are improving (clinically speaking) from experiencing muscle spasms, but a hard look at the data proves that you’re just lying to yourself.

  28. Jack Smith

    The detection of a muscle spasm is not evidence of a clinically desirable outcome in the case of muscle strain any more than the sight of a drop of blood is evidence of a successful vaccination injection.

    That is true. But the argument was that the point of insertion does matter when the desired outcome is to stimulate a particular muscle group. If you are going to claim there is no physiological effect other than minor trauma that causes a rush of adenosine, then you have to deal with the fact that athletes with muscle strains who have muscle groups stimulated by local insertions report reduced tension from acupuncture. A muscle spasm is not necessarily therapuetic — nor did I make that claim. But a muscle spasm is a physiological effect that is not an increase of localized adenosine.

    You can convince yourself that you feel better and/or are improving (clinically speaking) from experiencing muscle spasms, but a hard look at the data proves that you’re just lying to yourself.

    This is a logical leap a field afar from what I said and insulting. It has nothing to do with science.

  29. Leigh Jackson

    Regarding the safety of traditional medicine the WHO states:

    “There is some evidence that seems to support the use of traditional and complementary medicine – for example, acupuncture in relieving pain, yoga to reduce asthma attacks, and tai ji techniques to help elderly people reduce their fear of falls. WHO does not currently recommend these practices, but is working with countries to promote an evidence-based approach to addressing safety, efficacy and quality issues.”

    This falls well short of a WHO endorsement of acupuncture. Acupuncture organisations sometimes claim WHO endorsement on the back of a document published by the WHO in 2003. This document claimed that acupuncture had been proved to be of benefit for 28 medical conditions. This claim, however, was based on a hopelessly flawed systematic review which systematically excluded negative or neutral sham-controlled studies.

    The 1997 NIH consensus statement on acupuncture (not a statement of the NIH, but a snapshot opinion of a 12 member panel) found the evidence of efficacy for pain to be unclear. Only for adult postoperative and chemotherapy nausea and vomiting did they find clear evidence that acupuncture was efficacious. The bulk of published research on acupuncture was found to be of poor quality.

  30. Brian Too

    @7. DK Fennell & @8. Daniel R Hawes,

    You need a placebo control because the acupuncture treatment involves handling the animals. There is a well-known effect (although I cannot provide a reference at present) that sociable animals like mice do better on health and activity indicators when handled by people. As long as the contact is not traumatic, mice like human contact.

    Therefore a placebo control adds the human touch without the needle penetration. Without it, the mice may be responding physiologically to contact rather than to acupuncture.

  31. rabbitsaregood

    Surely if the adenosine is produced as a direct result of the needle piercing the skin, that isn’t a placebo effect, it’s a side effect.
    Surely the questions are: is this mechanism is correct? Can it be harnessed clinically? and do the special magic points have any effect on pain relief (and also which ones, and are any other points beneficial)?

  32. phayes

    “But the argument was that the point of insertion does matter when the desired outcome is to stimulate a particular muscle group.”

    That was your argument, and it is uncontroversial, but it is also irrelevant and, in particular, does not support your strawman in #15 and your assertion in #20 that Ed Yong was incorrect about the need for RCTs.

  33. Nathan Myers

    You can forget about “meridians”. Those were made up by a Frenchman as a learning aid, to help him organize where the points are, and have never been a part of Chinese medicine as practiced in China. Qi, therefore, is not there posited to follow meridians. Qi is said to flow, and we know of real substances in the body that flow, most particularly blood, and what it carries, including oxygen, hormones, platelets, T-cells, and probably many other things yet to be identified.

    Science begins with observation. The paper reports careful observations, and avoids unwarranted conclusions. We can’t avoid having hopes and expectations for any particular research project, but they’re not science. Science can only happen when you don’t pretend to know everything already. It’s sad when people who style themselves “skeptics” start out by assuming they already know as much as they need to.

  34. Phil Donnely Rooney

    I thought Phayes a little harsh. Traditional Chinese Medicine may be based on different health beliefs, but that does’t mean we shouldn’t look at observable &/or replicable effects.
    I agree with those who say placebo control is silly in mice.

  35. Leigh Jackson

    @Nathan 33

    Yes we know that blood flows. Flow implies regulation. The blood flows through channels due to controlled contractions of the heart. Mechanical energy is all that is required to explain the flow of blood.

    Science begins with the desire to understand what is not understood. We observe blood and the channels within which it flows and the cause of the flow. Qi is said to be energy. Where are the observations? How and where does it flow? What observations justify the claim that Qi exists?

    Science avoids unwarranted conclusions. Science avoids the conclusion of Qi and meridians.

    More accurately we ought to say that the veins and arteries carry the blood. Blood doesn’t carry those things you mention – those things compose blood.

  36. Leigh Jackson

    @Phil 34

    Placebo control in clinical trials is essential. And we now have a number of trials showing categorically that it does not matter where or whether needles are inserted.

    Animal tests, in and of themselves, can only offer clues for the effect of a medical treatment on humans. Does this study tell us something we don’t already know about the effect of acupuncture on humans? If so, what exactly? Because we then need to find out whether the same effect is found in humans – in placebo controlled clinical trials.

    This study alone and by itself is meaningless.

  37. Paul Browne

    Orac over at Respectful Insolence has written an excellent article on this study.


    He makes many of the same popints that you make about the lack of non-skin piercing controls and also discusses the fact that in the mice the site of needle insertion is far closer to the site of pain than it would be in humans, allowing a stronger local effect.

  38. Orac’s analysis is masterful and a must-read.

    Brian (@30) and Leigh (@35) have already mounted spirited defences as to why placebo controls are still necessary and relevant. I will only add to this by addressing this bit: “Science can only happen when you don’t pretend to know everything already. It’s sad when people who style themselves “skeptics” start out by assuming they already know as much as they need to.”

    Utter, utter straw man. No one here is suggesting that we already know as much as we need to, or behaving in that way. The entire point of this piece is that we already know quite a lot because acupuncture has been the subject of a massive amount of research, and that what we subsequently discover must be considered in the light of said research. Which this study fails to do. Of course it’s true that “science can only happen when you don’t pretend to know everything already” but science equally can’t happen if you ignore things you already know.

  39. Leigh Jackson

    Your own commentary was much appreciated, Ed.

    With Orac’s help I now see that the new clue from this study is not limited to suggesting further clinical tests of acupuncture. What is suggested is the generic testing of A1 receptor agonists close to nerve tracts local to a source of pain. Twisting needles around randomly (i.e. at non-local, prescribed acupuncture points) is unlikely to be the most effective method of obtaining an analgesic effect, if this study is meaningful.

    It just might be possible that the slight superiority of “de qi” acupuncture (stimulated needling) over sham acupuncture, which has been found in a number of studies, could be explained by this study.

  40. I browsed through the study, and the Methods section did not mention that the researchers were blinded. I think this could be a potential source of bias when evaluating the mice’s negative responses to the force and heat applied to their paws. I am not familiar with how these negative responses are measured, but I suppose it would be something like trying to remove the paw from the force or heat—an observation that could easily be contaminated by bias. (A researcher might see a non-pain-related slight twitch as a negative response, for instance, knowing that the mouse has not had acupuncture, or may be less likely to see it as a negative response in those that had acupuncture.)

    I concur that it would be nice to have more controls for this study. I also wonder if the placebo effect itself (or one of the wide ranges of placebo effects) is caused by adenosine. If so, then finding this would only show that acupuncture is a placebo, in that many placebos work through this mechanism.

  41. DK said:
    “I am wondering how can a placebo effect work in mice? I am asking this because it seems to me that surely mice don’t “believe” that acupuncture is going to work. If the “painkilling effect” really “only happened when she rotated the needles after insertion,” as you report the paper says, then what is a placebo control going to be used for?”

    Placebo effects are not just effects of beliefs about treatments, though many placebo effects are. For instance, some placebo effects are almost certainly the results of bias or poor study design. We see an effect only because of the poor quality of the study. Examples could be effects caused by researcher bias (researchers are unblinded, or using poor definitions of efficacy, or cherry-picking results), ignoring the natural history of a disease (symptoms tend to improve over time, and this could be misinterpreted as a medical effect), and various other issues.

    Also, placebo responses that are the result of conditioning could also be generated in animals. However, this study appears to have tried to control for that by giving the mice five minute breaks.

  42. Terra

    To state the obvious: The Chinese Medical system is not based on Western Medicine (it is not science based) so why is it people expect it to fit in to sciences boundaries. Now I know that you all believe that science can (if not now eventually) explain everything but this is nonsense. Is research in chinese medicine important? for some I guess, for me it doesn’t matter, whether science proves it works or not is not important.

    Am I for or against is also not important I am just perplexed at why the scientific world thinks it can put another system into science and get answers they can understand. It’s the same for meditation.

    Thousands of years of knowledge, intelligence and wisdom can only work if there is a scientific explanation otherwise it’s a placebo effect – arrogant????

  43. Terra

    p.s. I study western clinical medicine!

  44. Steven Novella has a typically eloquent take on Neurologica now too: http://www.theness.com/neurologicablog/?p=2015

    Terra – perhaps you might like to study a different subject where your relativism would be a better fit, and where you won’t have a chance of actually affecting anyone’s health as a result. Art history, perhaps?

  45. @ Terra: Who says we all believe science can explain *everything*?

  46. Orac’s article and Novella’s article are both insightful and informative. Along with this blog post by Ed Yong, these are some of the most interesting analyses I’ve seen of acupuncture analgesia research in a long time. Thanks very much for starting this useful discussion of the Nature Neuroscience piece!

  47. Nathan Myers

    Leigh: Where do you suppose this translation “energy”, for Qi, comes from? Do you imagine that Chinese people think they are saying “energy” when they say “Qi”? Or does it seem more likely that somebody made up the translation who knew practically nothing about any sort of medicine, or anatomy?

    — +++ —

    As proud as we are of the Science our ancestors took up whole from the writings of al Haytham, half a millennium after he invented it in the 11th century, it remains that the Chinese wrote of blood circulation (and of an essential component of air distributed through the body by it) fifteen centuries before Harvey rediscovered it. Science makes discovering and winnowing facts more efficient, but observation comes first. People had observation and reasoning, and used them successfully, long before al Haytham codified science, and longer still before English-speakers could bring themselves to be bothered with science.

    The West has achieved a lot, lately, but very late. It still has plenty to be embarrassed about, and there’s still far more left to learn than is known. The only people who will be discovering the former are the ones who don’t think they already know everything.

  48. Leigh Jackson


    Qi is commonly translated as “energy”. If it doesn’t mean energy what does it mean? It is said to flow. Something undefined is said to flow. Where to and where from? And now, what?

    We know that the blood flows because we can see it flowing out of bodies when we cut ourselves. You are saying that something invisible – but not energy – flows; but not in invisible channels. What use is any of this? Where are the observations which support it?

    Harvey’s experiments and reasoning epitomise the modern scientific method. In order to **demonstrate** the circulation of the blood you have to do pretty much what Harvey did. He did, however, have the benefit of having studied under Fabricius, who in turn had the benefit of having studied the works of Galen. To get the true picture is is no easy task. To guess is one thing, to demonstrate is quite another. One cannot properly appreciate Harvey’s achievement without reading “Exercitatio Anatomica de Motu Cordis et Sanguinis in Animalibus”. Harvey shows that the circulation of the blood is not only a fact of human biology but a fact of the animal world.

    It is science as we know it, and because it is, we now **know** that the blood circulates. History does not show that we knew this to be a fact before Harvey.

  49. Leigh Jackson

    Nathan, the reason I love science is because I am so ignorant and really don’t like being so. I believe most – if not all – scientists would say the same.

  50. Dudesitan

    That acupuncture has some physiological effects should not be in doubt. I suspect a weak biological effect combined with placebo explains why some patients find it helpful for pain.

    I think the question should not be ‘does acupuncture help relieve pain’, but rather how potent an analgesic is it? Or to put int another way, is it any better than paracetamol for long-term relief of pain?

  51. Nathan Myers

    Leigh: Air is invisible. Oxygen is invisibly different from other parts of air.

    The ancient Chinese performed dissections, as Harvey did, and thereby came to understand the roles of arteries and veins. They understood that something was extracted from air and distributed through the body through the arteries, although they didn’t have any way to know it was oxygen, per se. To insist that only Europeans could have discovered important facts of anatomy is incompatible with Science (because the cornerstone of Science is that anyone can repeat results by repeating observations) but entirely compatible with bigotry. The Chinese used a different language to report their results. Relying on ignorant translations can only lead you astray.

    Mystics can abuse any literature. Can you conclude anything about quantum mechanics from what mystics say about it?

    I have no trouble accepting that Chinese physicians may have observed phenomena, and learned how to act on their observations, that we have not, yet; different circumstances lead attention in different directions. It’s certain, too, that some concocted stuff as spurious as the phrenologists, and Freud, did, less than a century ago, because that’s how people are.

    They’ve been sticking little needles in people for many centuries, and studying the results. What would be surprising would be if there were no surprising results.

  52. Leigh Jackson

    Nathan, I hope you are not accusing me of bigotry. If I suggested that only Europeans could have discovered important facts of anatomy, let alone insist on it, I would certainly be a bigot Since I suggest no such thing I fail to see what point you are making.

    Area you accusing me of being a bigot, and if not, what point are you making?

    Can one conclude anything about the circulation of the blood – Harvey’s circulation – from the Neijing?

  53. Terra

    That’s right Ed science is the only truth! You absolutism is right where is should be!

  54. Jason Lester


    Considering that paracetamol/acetaminophen is the leading cause of acute liver failure in the United States and UK, it stands to reason that acupuncture could very well be “better” for long-term pain management than indefinitely popping 2000 mg a day.

    @Ed Young

    I don’t particularly see how being myopic about non-western traditions of knowledge is a particularly desirable trait for a medical practitioner. Perhaps you could explain why you seem to think it is.

    Medicine isn’t always concerned with what is “scientific.” It is, however, concerned with what is effective. Electroconvulsive therapy is highly effective for treating severe depression. Scientists still aren’t sure why that is – or even what electroconvulsive therapy actually does – but that doesn’t stop it from being prescribed to 1 million people a year. And scientific study has demonstrated that acupuncture is highly effective for treating osteoarthritis of the knee – if nothing else – whether or not there is a scientific explanation for that efficacy.

  55. Leigh Jackson


    Given that paracetamol accounts for most overdoses – intentional or not – it is hardly surprising that it is the cause of most cases of acute liver failure. The drug is not the guaranteed form of painless suicide that some hope for.

    Acupuncture is safer than a drug overdose; a prescribed dose of paracetamol is safer than a dirty needle.

    Dudestan’s real question, then, is whether a safe course of acupuncture is as effective or better than a prescribed course of paracetamol. This must be determined in placebo controlled trials.

  56. Nathan Myers

    Leigh: I am not accusing you of anything. I’m satisfied that you have just been misled (as most of us had been, myself included) by abominable translations, to believe falsehoods (“meridians”, “energy”) about the practice of Chinese medicine. Judging by the excellent article you reference (thank you) Chinese practitioners suffer far more from abysmal transcriptions of their own foundational documents. It’s remarkable they can do anything, under the circumstances.

    We know China had the beginnings of an industrial revolution similar in many details to Europe’s, but in the 15th century, along with a mathematical efflorescence, and then abandoned them both. But for an accident of history, Eastern science would have been the standard we measure against. Jared Diamond blames unification: each time the Empire went astray, it took all of China with it, while bits of Europe went in every direction at all times, with nothing useful abandoned by everybody at any time.

  57. Leigh Jackson


    Nie Jin-bao cites “two influential contemporary editions” of the original classic texts:
    Nanjing College of Chinese Medicine, ed., Huangdi Neijing Suwen:
    Translation and Commentary, Second Edition, Shanghai: Shanghai Science and Technology Press, 1981; and Nanjing College of Chinese Medicine, ed., Huangdi Neijing Lishu: Translation and Commentary, Shanghai: Shanghai Science and Technology Press, 1986.

    Although you describe Jin-bao’s article as excellent, the influential editions to which he refers are, you claim, abysmal transcriptions. As a description of the circulation of the blood they are considerably worse than abysmal. They simply don’t equate in any way, shape or form.

    So which transcription is not abysmal? Which transcription decribes something recognisably like Harvey’s demonstration of the circulation of the blood? Full reference, please.

  58. Leigh Jackson

    Apologies to Nie Jing-bao. I spotted the error seconds after the time check!

  59. I’m a skeptical acupuncturist, and am blogging about these sorts of issues, referencing the oldest classics of Chinese medicine as well as modern skeptical books such as Trick or Treatment and Snake Oil Science. Qi is more readily understood as breath and oxygen than it is as “energy.” Modern Chinese use the word Qi in chemistry for “gas,” such as “hydrogen qi” and “nitrogen qi.” The ancient texts talk about inhaling and exhaling Qi and modern TCM says “the blood carries the Qi.” You can read more of my take on it here: http://ancientway.com/blog/?p=201 If I had seen the Cochrane Collection systematic reviews of acupuncture in 1992, I would have become a research scientist, not an acupuncturst. But here I am, so I get to write about ancient Chinese demonology, psychedelic drug use, toxic herbs, and crazy acupuncture offshoots. Perhaps I’ll still be a research scientist some day.


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