Alternative medicine tends to live in a battlefield where treatments passed down for centuries clash with the often cold, hard truths of the scientific laboratory. Depending on your bias, one can trust the adherents of ancient practices such as chiropractic medicine or acupuncture, or one can remain skeptical until scientists prove that those therapies represent more than an elaborate placebo effect formalized through numerous generations. Those two worlds usually seem content to co-exist without crossing paths, so it’s interesting when a paper appears in a major journal not only addressing alternative medicine, but actually proposing a biological mechanism for it.
That happened over the weekend in Nature Neuroscience, where a team of researchers mostly from the University of Rochester Medical Center proposed a mechanism for pain relief via acupuncture. The study was centered around acupuncture performed in mice – sadly, there is no video provided – and co-treatment with various drugs to pinpoint (no pun intended) the effects of placing needles at a particular pressure point to relieve a mouse’s paw pain. Researchers concluded that adenosine, a molecule released after cell damage that has previously been identified in sleep regulation and inflammation, accounted for the analgesic effects of acupuncture. That is, when a needle is placed in the body and rotated or heated, adenosine levels are increased in the body and nerves that transmit pain information are inhibited.
“Acupuncture has been a mainstay of medical treatment in certain parts of the world for 4,000 years, but because it has not been understood completely, many people have remained skeptical,” author Maiken Nedergaard said in a press release. “In this work, we provide information about one physical mechanism through which acupuncture reduces pain in the body.”
Time to book an appointment at the acupuncturist, right? Slow down, the blogosphere responds. Ed Yong at the blog Not Exactly Rocket Science raises a number of thoughtful doubts about the study, from the lack of a control group to a potentially troublesome conflict of interest. Most interesting are Yong’s points about what isn’t in the paper – references to several papers that found little clinical value from acupuncture or studies that found “sham needles” which don’t break the skin are just as effective as the real thing. As such, Yong concludes that the new Nature Neuroscience study offers little support for the value of classic acupuncture, despite its interesting observations about adenosine and pain.
That’s my takeaway as well – acupuncture may be an interesting and time-honored way of inducing the natural pain relief of adenosine, but that doesn’t mean that acupuncture is the only or best way to trigger this response. In fact, some of the data in Nature Neuroscience suggests that drugs which activate the adenosine receptor directly (getting around the whole needle thing) can be effective in reducing neuropathic pain and the pain response to heat. Perhaps the adenosine system offers a new pathway by which people can be distracted from their pain, not unlike the research of Hayley Foo and Peggy Mason on food’s ability to reduce pain. If so, just as the thousand-year-old practice of chewing and smoking poppy plants has given way to fine-tuned opiate pain medications, the scientific mechanism behind acupuncture may be the discovery that renders it obsolete, not legitimate.