Have you ever wondered why your clients/patients feel so good after receiving bodywork: massage, manipulation and mobilization? Is it the simple effect of feeling more relaxed, with an altered mood, possibly combined with an actual reduction in muscle tone?^4,8 Or perhaps feeling better/good accompanies enhanced circulatory function deriving from bodywork?⁷ Or possibly it's due to endorphin release and consequent reduction in pain perception, as has been suggested?^6,15 Or does bodywork produce an "energy" effect, as Oschman and others have described?¹²

Or perhaps all of the above? Or could it be due to something else altogether, such as the increased production of endocannabinoids -  chemicals that mimic the effects of cannabis?¹¹

Research

Research suggests that all of these effects can occur in response to appropriately applied bodywork. The data related to this research are readily available, and much of it is probably familiar to you - apart perhaps from the last observation regarding endocannabinoids. And that is the topic I want to explore in this brief article.

Endorphins - Changing Views

Before discussing the endocannibanoids, it will be useful to discuss something we are perhaps more familiar with - the topic of endorphins.

Opioid receptors in the brain, as well as these neuropeptide substances (the name derives from an abbreviation of endogenous morphine, which literally means morphine produced naturally in the body) were first identified in the mid-1970s by different groups of investigators.^3,14 Endorphins have a pain-killing influence and produce a sense of well-being, and it has become common to use the term "endorphin rush" to refer to feelings of exhilaration.

Also widely accepted for many years as an endorphin effect is the so-called "runner's high" following strenuous exercise. Endorphins were thought by many to be released during lengthy aerobic workouts, especially when stored glycogen is exhausted, such as during running, long-distance rowing, swimming and cycling. However, the mechanisms involved have however been questioned.⁵ Fairly recently, the link between the "runner's high" and endorphins has been virtually abandoned, since a study in 2004 by Dietrich and McDaniel² demonstrated that these pleasant feelings were actually the result of the release of a different, naturally produced body chemical - the endocannabinoid anandamide.

Anandamide is similar to the active chemical THC in marijuana. Apparently, the body produces it in response to prolonged stress and pain - for example, strenuous exercise. When people illegally use cannabis/marijuana as a means of easing their pain symptoms, the THC works by mimicking endogenous (self-produced) anandamide, which binds to the same cannabinoid neuroreceptors and imparts pain-relieving effects.⁹

As Dietrich and McDaniel report, "Exercise induces changes in mental status, particularly analgesia, sedation, anxiolysis and a sense of well-being. The mechanisms underlying these changes remain unknown. Recent findings [however] show that exercise increases serum concentrations of endocannabinoids, suggesting a possible explanation for a number of these changes."²

Not Only Exercise - Bodywork

Darmani, et al.,¹ have noted that anandemide is produced in the body, not only in response to aerobic activity or pain, but also as a response to bodywork (such as massage, deep-tissue work, high-velocity [HVLA] manipulation/adjustments, etc.) and according to McPartland, et al.,¹⁰ 4VC in cranial treatment. Anandemide may therefore account, at least in part, for the sense of well-being that follows such treatments, most specifically anti-inflammatory and pain-relieving benefits.

Enhanced release of endocannabinoids may be one of the mechanisms of osteopathic (and chiropractic) manipulative treatment,^10,11 parallel to the effects of manipulative treatment on serum endorphin levels.¹⁵ The endocannabinoid (eCB) system balances sympathetic-parasympathetic tone, imparts anti-emetic and antihypertensive benefits, and favorably modulates stress in the HPA axis.¹³

As we all know, there are numerous beneficial effects from bodywork, and this particular area offers yet another for us to consider and carefully explain to patients/clients.

References

1. Darmani N, et al. Involvement of the cannabimimetic compound, N-palmitoyl-ethanolamine, in inflammatory and neuropathic conditions. Neuropharmacology. June 2005;48(8):1154-63.
2. Dietrich A, McDaniel W. Endocannabinoids and exercise. Br J Sports Med. Oct. 2004;38(5):536-41.
3. Goldstein A, Lowery P. Effect of the opiate antagonist naloxone on body temperature in rats. Life Sci. Sept. 1975;17(6):927-31.
4. Field T, et al. CFS: massage therapy effects depression and somatic symptoms in CFS. Journal of Chronic Fatigue Syndrome. 1997;3(3):43-51.
5. Hinton E, Taylor S. Does placebo response mediate runner's high? Percept Mot Skills. June 1986;62(3):789-90.
6. Hou C-R, et al. Immediate effects of various physical therapeutic modalities on cervical myofascial pain and trigger-point sensitivity. Arch Phys Med Rehabil. Oct. 2002;83(10):1406-14.
7. Ikimi F, et al. Interstitial fluid plasma protein, colloid, and leukocyte uptake into initial lymphatics. J Appl Physiol. Nov. 1996;81(5):2060-7.
8. Lederman E. Science and Practice of Manual Therapy, 2nd Ed. New York, Edinburgh: Churchill Livingstone, 2005.
9. McPartland J, Pruitt P. Side effects of pharmaceuticals not elicited by comparable herbal medicines: the case of tetrahydrocannabinol and marijuana. Altern Ther Health Med. July 1999;5(4):57-62.
10. McPartland J, et al. Cannabimimetic effects of osteopathic manipulative treatment. J Am Osteopath Assoc. June 2005;105(6):283-91.
11. McPartland J, Simons D. Myofascial trigger points: translating molecular theory into manual therapy. J Manual Manipulative Therapy, 2006;14(4):150-7.
12. Oschman JL. Energy Medicine: The Scientific Basis. New York, Edinburgh: Churchill Livingstone/Harcourt Brace, 2000.
13. Pertwee R. The therapeutic potential of drugs that target cannabinoid receptors or modulate the tissue levels or actions of endocannabinoids. AAPS J. Oct. 24, 2005;7(3):E625-54.
14. Simantov R, Snyder S. Morphine-like peptides in mammalian brain: isolation, structure elucidation, and interactions with the opiate receptor. Proc Natl Acad Sci USA. July 1976;73(7):2515-9.
15. Vernon H, et al. Spinal manipulation and beta-endorphin. J Manipulative Physiol Ther. June 1986;9(2):115-23.