News blog

Acupuncture ‘works in mice’

Long derided by much of the mainstream medical community, acupuncture may have just got a little bit less alternative.

Despite thousands of years of anecdotal evidence claiming benefits in treating ailments from allergies to hiccups, acupuncture faces two big challenges to acceptance in mainstream medicine: most clinical trials have found no evidence of efficacy; and there is no scientifically accepted mechanism for how the treatment could work. Many researchers assume that any benefits are down to the placebo effect.

Now, research in mice has provided a biochemical explanation that some experts find more persuasive, although it might account for only some of the treatment’s supposed benefits. “Our study shows there is a clear biological mechanism behind acupuncture,” says Maiken Nedergaard, a neuroscientist at the University of Rochester, New York, who led the research, published in Nature Neuroscience.

Nedergaard’s team were interested in finding out whether the neuromodulator adenosine, which is produced on tissue injury and has pain-dulling properties, was involved in the pain-relieving effects of acupuncture.

After inducing chronic pain in the right legs of their mice, the researchers inserted and rotated an acupuncture needle just below the ‘knee’, at a point known in humans as the ‘Zusanli point’. For about an hour after the treatment, the mice took longer to respond to touch or heat on the paw, indicating that their pain had been dulled.

The scientists found that the needle had caused tissue damage; they also noted an increase in local levels of a number of biologically active molecules, including adenosine.

Mice lacking a key receptor for adenosine did not show the same response after acupuncture.

Edzard Ernst, who studies the effectiveness of alternative therapies at the Peninsula Medical School in Exeter, UK, says that the mechanism is credible. But the work does not address whether acupuncture is actually an effective treatment, he adds. “If the clinical effect is not beyond placebo, which most of the well controlled clinical trials seem to suggest, the mechanism is irrelevant and the true mechanism is placebo,” he says.

Posted on behalf of Dan Cressey

Comments

  1. Report this comment

    David Colquhoun said:

    What on earth is Nature thing of, publishing stuff like this?

    It took no time at all for this silly hyperbole to be demolished in the blogosphere where, not for the first time, you find people with more critical minds than you find in eminent journals.

    I recommend https://bit.ly/a003ff

  2. Report this comment

    David Colquhoun said:

    Two days later, my comment looks perhaps a bit harsh. This blog post does at least fill in some of the context, though. Nevertheless starting with “acupuncture may have just got a little bit less alternative”, doesn’t much help.

    The newspaper coverage of this item has been almost entirely dreadful, but I’d guess that is more the fault of the press release issued by Nature Neuroscience than of this blog. The press release starts

    “Acupuncture can relieve many kinds of pain, but it remains unclear how it might work, . . "

    That gives at once a quite wrong impression of the state of play in human acupuncture research. I feel that eminent journals must bear some responsiblility for dreadful newspaper reports, because they must know that many journalists have neither the time nor the inclination to look beyond the press release. In this case, I think the press relase was more aimed at getting attention for the journal. or telling a story that would get covered, than it was about a critical asseesment of acupuncture.

  3. Report this comment

    Ruth Francis said:

    David,

    The sentence from the release that you’ve quoted finishes: but it remains unclear how it might work, beyond the possibility of a strong placebo effect.

    The press release also makes it clear that the work was done in mice and not humans.

    Finally it concludes with a warning:

    It should be noted that while this work suggests a mechanism for local pain relief by acupuncture, it does not in any way endorse the ancient mystical idea that the needles work by correcting some aberrant “qi” energy flow along “meridians”. Instead, the authors propose a model whereby the minor tissue injury caused by rotated needles triggers adenosine release, which, if close enough to pain-transmitting nerves, can lead to the suppression of local pain.

    The release, in full, is pasted here so readers can judge for themselves:

    How needles pierce pain

    DOI: 10.1038/nn.2562

    Acupuncture can relieve many kinds of pain, but it remains unclear how it might work, beyond the possibility of a strong placebo effect. A study published online in Nature Neuroscience now shows that acupuncture locally activates pain-suppressing receptors which could be the key to the treatment’s ability to relieve pain.

    Maiken Nedergaard and colleagues inserted fine needles into the mouse equivalent of a traditional acupuncture point near the knee, and rotated these needles intermittently as is practiced by acupuncturists. This alleviated the pain reactions of mice with an inflamed paw, and it also strongly increased the local tissue concentration of the neurotransmitter adenosine. Pain relief required the presence of a particular adenosine receptor. It is known that this receptor resides on pain-transmitting nerve fibers and can reduce the activity of these fibers. The authors found that no pain relief or adenosine elevation was observed when the needles were simply inserted into the acupuncture point without rotation. They also noted that a drug that prolongs the lifetime of adenosine in live tissue helped to prolong the pain-attenuating effect of mouse acupuncture.

    It should be noted that while this work suggests a mechanism for local pain relief by acupuncture, it does not in any way endorse the ancient mystical idea that the needles work by correcting some aberrant “qi” energy flow along “meridians”. Instead, the authors propose a model whereby the minor tissue injury caused by rotated needles triggers adenosine release, which, if close enough to pain-transmitting nerves, can lead to the suppression of local pain.

  4. Report this comment

    Charles Shang said:

    Although the clinical trials using multiple acupuncture points for various pain syndromes often showed mixed results, clinical trials using acupuncture point PC6 for nausea and vomiting have been overwhelmingly positive: Lee A, Fan LTY. Stimulation of the wrist acupuncture point P6 for preventing postoperative nausea and vomiting. Cochrane Database of Systematic Reviews 2009, Issue 2. Art. No.: CD003281. Current research on acupuncture mechanism has already met the gold standard of science: The growth control model suggests that acupuncture points originate from organizers in developmental biology. This model has correctly predicted multiple research results (independently confirmed) not only in acupuncture, but also in conventional developmental biology. (Shang C. Prospective tests on biological models of acupuncture. Evid Based Complement Alternat Med. 2009 Mar;6(1):31-9. https://ecam.oxfordjournals.org/cgi/content/full/6/1/31)

  5. Report this comment

    phayes said:

    “Finally it concludes with a warning”.

    So the press release tries to undo some of the damage done by the spurious and credulous references to acupuncture in the paper. That’s good but clearly it’s hard to avoid compounding the error and really it’s too late anyway isn’t it? Better just to have had the paper cut down to the science it contains before publishing it in the first place.

  6. Report this comment

    Charles Shang said:

    The growth control model, which is the first model of acupuncture mechanism with independently confirmed predictive power in multiple disciplines, also offers explanation why many clincal trials on acupuncture showed mixed results while using PC6 (P6) for nausea and vomiting has showed overwhelmingly positive results over placebo (https://ecam.oxfordjournals.org/cgi/content/full/6/1/31). This model predicts that acupuncture is most effective as early treatment of patients with few comorbidities and selective use of few acupoints. According to this model, using too many acupoints in the treatment group with several comorbidities, just like polypharmacy in conventional medicine, has contributed to the mediocre results which are indistinguishable from those of sham group in some clinical trials. As predicted, the efficacy of acupuncture has been shown to be inversely correlated to the disease chronicity, severity and patient’s age (Zhou et al. J Tradit Chin Med 2009; Mar;29:39-42.) This is due to the self-regulatory nature of organizers which decline in function with aging and severe chronic diseases. Stimulating organizers/acupoints enhances the self regulation of the growth control system. Not surprisingly, adenosine is not only a neurotransmitter, but also a growth control factor (Zavialov et al. Human adenosine deaminase 2 induces differentiation of monocytes into macrophages and stimulates proliferation of T helper cells and macrophages.

    J.Leukoc.Biol., 2010.

    Sun et al. The A(2A) adenosine receptor rescues neuritogenesis impaired by p53 blockage via KIF2A, a kinesin family member

    Dev.Neurobiol., 2010.)

  7. Report this comment

    Carlos said:

    I’m happy to see that more research is being done on acupuncture. It’s only been around for thousands of years!!!

  8. Report this comment

    orchidacupuncture said:

    Chinese Medicine and Acupuncture are first and foremost a preventive type of medicine. It is lack of information that makes people wait until it is to late to prevent disease. We are not in tune with our own bodies, and we pay dearly for it. I believe that the way Chinese medicine looks at health can help give us a better hold on the prevention aspects of Medicine

  9. Report this comment

    Acupuncture Rochester said:

    Acupuncture’s effectiveness has been seen many times. Truth of the matter, people can live longer without oral medication for as long as acupuncture professionals are around.

  10. Report this comment

    Giles Watts said:

    I find it amusing that such a specific point can be transferred from a persons anatomy to a mouses knee . . . I’m not a trained medic . . . but this does seem odd.

    The research into acupuncture is however essential to get credit for this ancient medicine. But, I hope that a reliance on research does not limit the scope of acupuncture if no mechanism is found. As this does not mean that it does not work.

  11. Report this comment

    acupunture clinic London said:

    Great study, thanks for explaining every point in details, that will helpful for understanding of the acupuncture.

  12. Report this comment

    San Francisco Chiropractor said:

    Acupuncture is powerful and shouldn’t be seen as an old ancient “magical” healing property. If its working on mice then we need to start adjusting the treatment for humans.

Comments are closed.