At the risk of repeating myself (but, then, since when did such concerns ever stop me before?), I’ll just start out by mentioning that, of all the non-herbal “alternative” medicine remedies out there, I used to give a bit of a pass to acupuncture. No, I never did buy any of that nonsense about how sticking thin needles into the skin at points along various “meridians” somehow “redirects the flow of qi,” that mystical life force upon which so much woo, particularly woo based on Eastern mysticism and traditional Chinese medicine depends. However, because acupuncture involves an actual physical action on the body, namely sticking needles in it, I didn’t think it entirely implausible that it might have some sort of physiological effect, such as counterirritation or the release of endorphins, that could relieve pain or induce relaxation.
Of course, back then I was still fairly early into my skeptical career of investigating “alternative” medicine claims and hadn’t read very many the studies of acupuncture. The more I read, the more I realized that acupuncture is nothing more than yet another elaborate placebo. What it took over the last couple of years for me to give up on acupuncture entirely was reading a steady stream of studies showing that “real” acupuncture is no better than “sham” acupuncture involving either using special needles that don’t break the skin, locations other than the true “meridian” points, or even toothpicks. Heck, in one case, sham acupuncture worked better than “real” acupuncture, but the study authors argued that their study was evidence that “acupuncture works”! In fact, virtually every study that shows no difference between acupuncture and sham acupuncture is still somehow spun by its authors as providing evidence that “acupuncture works” (although they usually do a bit of handwaving and represent it as “more complex” than previously thought). The more I learned, in other words, the more I asked: Can we finally just say that acupuncture is nothing more than an elaborate placebo? When I started to learn that what is represented as acupuncture today is, in fact, not really even that ancient but rather a modality resurrected by Chairman Mao to give the appearance of bringing health care to his people when he couldn’t afford modern, scientific medical modalities, that about sealed it. I saw acupuncture for what it is.
Perhaps realizing that what has been known as acupuncture is indeed no better than an elaborate placebo, acupuncturists have been trying all sorts of variations of acupuncture, the most common of which involves hooking up the acupuncture needles to a weak electrical current, a procedure that has come to be known as “electroacupuncture.” Heck, acupuncturists have even tried a variation involving lasers (because, of course, everything is better with laser beams, and, like Dr. Evil, I think that strapping lasers even to ill-tempered sea bass would be cool, although I must agree with him that it would be much cooler to have sharks with laser beams to dispatch my enemies). Here’s the problem. What acupuncturists call “electroacupuncture,” we in the medicine biz call transcutaneous electrical nerve stimulation (abbreviated TENS). What acupuncturists don’t tell you is that electroacupuncture is, in essence, TENS without science or any scientific rationale for the placement of the electrodes (which is, after all what the needles become when hooked up to an electrical source). In effect, electroacupuncture replaces science-based positioning of the electrodes with woo-based positioning. Despite that, though, it actually sometimes works, because, as TENS shows, using a weak electrical current to stimulate certain nerves can indeed relieve pain in some cases, and that’s all so-called “electroacupuncture” does. Mainly this occurs by utter coincidence, when acupuncture meridian points happen to overlie actual nerves. Indeed, I strongly suspect that the reason many of these acupuncture points are selected for various studies isn’t based on traditional Chinese medicine precepts, but because it was realized that they were close to real nerves that might do real things in the body when stimulated.
Here’s the problem. Acupuncturists take a science-based modality (TENS) and “rebrand” it as some sort of “alternative” therapy like electroacupuncture. After all, why use boring old TENS to try to relieve chronic pain when you could instead be using–ta da!–electroacupuncture. So much cooler So much more…alternative! It’s a classic bait and switch, in which woo-meisters take a modality like acupuncture, add something to it that science tells us will have a physiological effect (like electricity), find a result, and then use that to imply that the whole “alternative” medicine modality really does work after all.
That’s exactly what advocates of electroacupuncture do.
What brought this up is a post by fellow ScienceBlogger Isis. who the other day asked: Is electroacupuncture an effective treatment for hypertension? In it, Isis applied her hot scientific skills to a paper that looked at a paper examining a rat model of hypertension and whether electroacupuncture can lower blood pressure. Before I get to my take on the paper, let me just say that (1) I’m not a neuroscientist (although, whether Isis will believe it or not, I do study a glutamate receptor, in one of the more bizarre and lucky bits of serendipity between neuroscience and cancer I’ve ever come across) and (2) there’s no reason for me to delve too deeply into a discussion of the rat model because there’s no reason for me to think I can do it better than Isis, whose science hotness is indisputable. What I do bring to the discussion that Isis lacks are (1) my background as a physician and (2) my background dealing with the classic bait and switch of alternative medicine woo-meisters, which Isis clearly lacks, which allows me to cut through the woo-speak that inevitably infests papers such as this, even ones that use a well-established animal model that, unlike the infamous “reiki for rats” experiment that I had so much fun deconstructing a while back, isn’t ridiculous. However, the introduction to the paper is:
ELECTROACUPUNCTURE (EA), a potent alternative to manual acupuncture, has been suggested to be effective in treating certain cardiovascular diseases including hypertension, arrhythmias, and angina pectoris (5, 6, 41). Clinically, EA at the Neiguan- Jianshi (P5-6) acupoints has been used to treat cardiovascular diseases in Eastern and, more recently, Western countries (5, 21, 41). We and others have demonstrated that EA at P5-6 acupoints overlying the median nerve on the wrist modulate blood pressure elevation evoked by gastric distension (GD) in rats (27) or by gallbladder stimulation in cats (50) through a long-loop neural pathway, extending from the arcuate nucleus (ARC) in the hypothalamus to the ventrolateral periaqueductal gray (vlPAG) in the midbrain and, ultimately, to the rostral ventrolateral medulla (rVLM) (13, 26, 50, 58).
First off, let me make this very, very clear. these Neiguan-Jianshi acupoints have no basis in human anatomy or physiology. Really, they don’t, any more than any acupuncture point does. “Meridians” are based on a prescientific understanding of how the human body works, and the thought that sticking needles into these “meridians” redirects the flow of “qi” in order to heal is nothing more than magical thinking. These particular acupoints, probably through blind, dumb luck, happen to lie over a major nerve in the forearm, namely the median nerve. Sticking needles near the nerve would not necessarily be expected to do anything, but running electrical current near enough to stimulate the nerve might actually be expected to do something, given that the impulse thus generated would be expected to travel up the median nerve. The median nerve, by the way, is the nerve that is compressed in carpal tunnel syndrome, and its compression can, as anyone who’s ever had a bad case of carpal tunnel syndrome can tell you, can result in pain radiating up the arm to the neck and even to the head.
To make a long story short, what the investigators had found in a previous study that stimulating the median nerve with electrical current using the P5-6 acupuncture points blunted the increase in blood pressure caused by dilating the stomach in anesthetized rats. This study tried to identify the mechanism for the effect. Specifically, using stereotactic techniques, the investigators placed microdialysis probes into specific areas of the rat brain in order to take samples of the cerebrospinal fluid and infuse drugs. At this point, I’ll let Isis summarize the results:
Fu and Longhurst collected samples of cerebral spinal fluid and delivered drugs to block a receptor they thought might be mediating the response to the electroacupuncture while they stimulated the hypertensive rats at acupoints P 5-6. Electroacupuncture was effective in preventing 50% of the gastric distension-induced increase in blood pressure and caused a decline in the neurotransmitter GABA in the ventral IPAG (vIPAG), a brain region whose activation has been shown to lower blood pressure. Administration of AM251, a drug that blocks the cannabinoid type 1 receptor, to the vIPAG prevented the electroacupuncture-induced decline in GABA. AM251 did not, however, alter blood pressure and the investigators do not appear to have used it in combination with their gastric distension technique.
So, what’s the point Isis? While the authors do not quite seal the deal, defining a specific causative link between the cannabinoid type 1 receptor, GABA, blood pressure, and electroacupuncture, they provide compelling evidence that electroacupuncture causes discrete biochemical changes in a region of the brain responsible for lowering blood pressure.
Actually, what the authors in reality showed (probably) is that stimulating the median nerve near the P5-6 acupuncture points with a weak electrical current blunted the increase in blood pressure caused by gastric distension and that blocking the canniboid type 1 receptor prevented the stimulation of the median nerve from lowering blood pressure. I’m a stickler for nomenclature when it comes to these things, and that’s how the results of this study should have been represented. The reason I’m a stickler for nomenclature is because, as I mentioned in the introduction, “rebranding” various science-based treatments and appropriating them as somehow “alternative” is how CAMsters operate. (Just look how they’ve appropriated diet and exercise, if you don’t believe me.) In any case, I can think of one obvious control that wasn’t done that should have been done, namely ablation of the median nerve well proximal to the P5-P6 acupuncture points. If ablation of the median nerve prevents the effect of electroacupuncture, that would nail it as far as stimulation of the median nerve being the mechanism by which the observed effect of electrical stimulation.
The thing that bothers me about this study is that it’s a lot of careful science that is corrupted by the taint of ideology. Instead of representing their results as what they were, namely that median nerve stimulation at the wrist can lower blood pressure by whatever mechanism, they fit it into the whole world view of acupuncture, which in turn depends upon the mystical world view of traditional Chinese medicine. Why on earth did they do that? The science they did was interesting enough without needing to invoke woo to sex it up. Is it because they buy into the ideology that postulates that sticking needles into the skin somehow redirects a mystical life force called qi to healing effect? Who knows? Shockingly enough, it wasn’t the National Center for Complementary and Alternative Medicine that funded this study, but rather the National Heart, Lung, and Blood Institute. Is it because the authors know that it’s much sexier to label what they are doing “electroacupuncture” than as TENS focused on the median nerve? Is it because they are believers in acupuncture who couldn’t find evidence that it does anything without the electric current? Who knows?
Of course, one other aspect of this study is the question of how durable the response is. Let’s assume for the moment that the results of the study are valid. Let’s assume even more than that. Let’s assume that the results are generalizable to humans. The question then becomes: Other than the interesting physiology, so what? Unless the response is quite durable (as in days or weeks), who on earth would want to be hooked up to electrodes once a day or once every few days rather than just take a pill? In any case, even if this study guides us to a technique of treating human hypertension by sticking needles in the wrist and stimulating the median nerve, would such a treatment be practical? Sorry, it’s the clinician in me talking, as opposed to the basic scientist. I can’t help it.
In the meantime, as much as I hate to be critical to Isis in any way, given her dedication to “hot, hot science” (although I admit, male that I am, I fail to understand her apparent obsession with shoes), her post is evidence of the insidious effect that studies such as these have. They are what Harriet Hall refers to as “Tooth Fairy science” in that they apply the methods of science to a phenomenon that is the equivalent of the Tooth Fairy. That in this case there seemed to be some science to study is the exception that proves the rule in that the results of this study are being misrepresented as evidence that there is something to acupuncture. That advocates of unscientific modalities of health care continue to call this sort of nerve stimulation “electroacupuncture” rather than the science-based modality that it is, unfortunately, works as propaganda, even among hard core purveyors of hot science like Isis.
Fu, L., & Longhurst, J. (2009). Electroacupuncture modulates vlPAG release of GABA through presynaptic cannabinoid CB1 receptors Journal of Applied Physiology, 106 (6), 1800-1809 DOI: 10.1152/japplphysiol.91648.2008