As a postgraduate student studying acupuncture, I found myself curious as to why and how acupuncture works. I could see it working with patients under the care of, my then mentor, Dr Northcutt D.C. who had been practicing acupuncture for almost 2 decades. I couldn't help but wonder if there is something mystical behind it or can it all be explained from a modern physiological standpoint. I did a little research (the real kind) to try and shed some light onto this phenomenon. What follows is a summary of my findings.

​

What Can Acupuncture Treat and How Does It Do It?

 

The purpose of this paper will be to explore the many different traditional acupuncture points that have research backing their influence upon the many different body systems and their positive influence along with the substantiated effects of acupuncture in general. It has been shown time and time again that acupuncture can have real effects on the body. Some of the outcomes have been documented well whereas others require more studies to confirm observations made in practice. 
   

The first and perhaps most well known is the ability of acupuncture to reduce pain levels in both acute and chronic conditions. For instance, even ear acupuncture has been shown to reduce chronic low back pain better than placebo. (1) A correlation of acupuncture points to well known trigger point locations has been looked at several times. In one study the authors noted that “Myofascial trigger points are significantly correlated to Traditional Chinese Medicine acupoints, including primary channel acupoints, extra acupoints, and Ah-shi points. Considering the correlation between MTrPs and acupoints and the rarely-studied research area of Ah-shi points, it may be reasonable to incorporate research findings of myofascial trigger points into further investigations into Ah-shi points. Correspondence between myofascial trigger points and acupoints enhances contemporary understanding of the mechanism of action of acupuncture, and may serve to facilitate increased integration of acupuncture into clinical management.” (2) An experienced acupuncturist will often note that when treating musculo skeletal conditions the so called Ah-shi points are often the most powerful points to needle. This observation has spawned the insurgence of “dry-needling” for musculo skeletal conditions in both the physical therapy and chiropractic communities. 
 

It is broadly accepted that “Dry needling is an effective treatment for reducing pain associated with active myofascial trigger points” (3) with the research showing that it can help with a multitude of conditions including headaches, myofascial pain, sciatica, osteoarthritis, rotator cuff injuries and torticollis. (4) The research on acupuncture tends to show support for the efficacy of acupuncture especially when combined with more typical treatments. For instance “A 2008 systematic review of studies on acupuncture for low-back pain found strong evidence that combining acupuncture with usual care helps more than usual care alone.” but it also showed “that there is no difference between the effects of actual and simulated acupuncture in people with low-back pain.” (5) This is somewhat varied by region and condition. As a matter of fact, the same outcome was found when treating osteoarthritis of the knee in a 2014 study. “A clinical study involving 282 men and women showed that needle and laser acupuncture were modestly better at relieving knee pain from osteoarthritis than no treatment, but not better than simulated (sham) laser acupuncture. ” 
 

The same cannot be said for certain points known to have particular physiologic effects. Perhaps the best example is in hypertension where “Low-current and low-frequency electroacupuncture (EA) at P5-6 (overlying the median nerve) and S36-37 (overlying the deep peroneal nerve) reduced high blood pressure in a subset of patients (~70 %) with mild-to-moderate hypertension, in a slow-onset (4-8 weeks) but long-lasting (1-2 months) manner.” (6) This represents a case where the acupoint itself may bear a therapeutic property as opposed to the method of treatment even though in the above cited study Electroacupuncture was used. Another well known application of acupuncture is in dentistry. A brazilian study on dental pain used three points to effectively control dental pain. In the study “all patients underwent one session of acupuncture; the points LI4, ST44 and CV23 were selected and were used alone or in combinations. Reduction in pain was observed in 120 patients (mean initial VAS=6.558±1.886, p<0; mean final VAS=0.962±2.163, p<0.00001). The results of this study indicate that acupuncture analgesia could be a technical adjunct to pain control in patients with acute dental pain, contributing to the restoration of health with social benefit.”. (7)

It is clear that certain points used in acupuncture yield more physiologic power and consequently more clinical applicability. What is not clear is why. Several studies have attempted to extrapolate why needle placement in certain points or, as is the case with low back pain, just needle placement should have such an effect. One example of a proposed and well documented mechanism of acupuncture is the release of ATP “in response to either mechanical and electrical stimulation or heat. Once released, ATP acts as a transmitter that binds to purinergic receptors, including P2X and P2Y receptors ATP cannot be transported back into the cell but is rapidly degraded to adenosine by several ectonucleotidases before re-uptake. Thus, adenosine acts as an analgesic agent that suppresses pain through Gi-coupled A1-adenosine receptors”. In the same study it is noted that “adenosine may accumulate during these treatments and dampen pain in part by the activation of A1 receptors on sensory afferents of ascending nerve tracks. Notably, needle penetration has been reported to not confer an analgesic advantage over nonpenetrating (placebo) needle application”. (8) More gennerally acupuncture may act by “affecting other pain-modulating neurotransmitters such as met-enkephalin and substance P along the nociceptive pathway”. From a purely musculoskeletal point of view local acupuncture leads to “increased local blood flow, facilitated healing, and analgesia.” (9) Despite the rigorous academic effort to delineate a physiological effect of acupuncture none are generally accepted mechanisms to explain why acupuncture has such varied and powerful effects.

In conclusion, we can see that acupuncture is supported by current literature in the treatment of many conditions. However, in the majority of conditions acupoints are not specific. Many times sham acupuncture was indiscernible from actual acupuncture. Clinical applicability of this finding suggests that point protocols for these conditions are irrelevant so long as needles are placed along with typical treatments. In contrast, there exist several well studied points that have profound effects in conditions like TMJ, Hypertension and dental pain to name a few although a clear mechanism is not fully understood. (6)(7) While research on acupuncture is in no way scant, it has proven to be difficult to separate from placebo and to study in general. (9) It is clear that more research is needed to fully understand what it is that acupuncture can efficaciously treat and how it works. 

​

​

​

1

Braz J Phys Ther. 2016 Jun 16;0:0. doi: 10.1590/bjpt-rbf.2014.0158.
Effect of a single session of ear acupuncture on pain intensity and postural control in individuals with chronic low back pain: a randomized controlled trial.
Ushinohama A1, Cunha BP1, Costa LO2,3, Barela AM1, Freitas PB1.

​

2

Complement Ther Med. 2016 Jun;26:28-32. doi: 10.1016/j.ctim.2016.02.013. Epub 2016 Feb 22.
Traditional Chinese Medicine acupuncture and myofascial trigger needling: The same stimulation points?
Liu L1, Skinner MA2, McDonough SM3, Baxter GD4.

​

3

PM R. 2016 Jun 10. pii: S1934-1482(16)30180-0. doi: 10.1016/j.pmrj.2016.06.006. [Epub ahead of print]
"Beneficial Effects of Dry Needling for Treatment of Chronic Myofascial Pain Persist for 6 Weeks After Treatment Completion".
Gerber LH1, Sikdar S2, Aredo JV3, Armstrong K4, Rosenberger WF5, Shao H5, Shah JP3

​

4

https://nccih.nih.gov/health/acupuncture/introduction

​

5
Yuan J, Purepong N, Kerr DP, et al. Effectiveness of acupuncture for low back pain: a systematic review. Spine. 2008;33(23):E887–E900.

6

Chin Med. 2015 Nov 30;10:36. doi: 10.1186/s13020-015-0070-9. eCollection 2015.
What do we understand from clinical and mechanistic studies on acupuncture treatment for hypertension?
Cheng L1, Li P2, Tjen-A-Looi SC2, Longhurst JC2.

7

J Acupunct Meridian Stud. 2014 Apr;7(2):65-70. doi: 10.1016/j.jams.2013.03.005. Epub 2013 Apr 11.
Acupuncture in the management of acute dental pain.
Grillo CM1, Wada RS1, da Luz Rosário de Sousa M2.

​

8

Nat Neurosci. 2010 Jul; 13(7): 883–888.
Published online 2010 May 30. doi:  10.1038/nn.2562
PMCID: PMC3467968
NIHMSID: NIHMS411155
Adenosine A1 receptors mediate local anti-nociceptive effects of acupuncture
Nanna Goldman,1,4 Michael Chen,1,4 Takumi Fujita,1,4 Qiwu Xu,1 Weiguo Peng,1 Wei Liu,1 Tina K Jensen,1 Yong Pei,1Fushun Wang,1 Xiaoning Han,1 Jiang-Fan Chen,2 Jurgen Schnermann,3 Takahiro Takano,1 Lane Bekar,1 Kim Tieu,1 and Maiken Nedergaard1

​

9

J R Soc Med April 1995 vol. 88 no. 4199-202
Placebo Controls for Acupuncture Studies
Charles Vincent, MPhil PhD⇑1
George Lewith, MRCP MRCGP2