Research indicates that acupuncture has a number of physiological effects.  Because of this, there is not a short, simple answer to the question of how acupuncture works. Rather, from a western point-of-view, acupuncture involves a variety of different mechanisms:[1]

·         Releases the body's own opioids to relieve pain

·         Stimulates gate control and initiates diffuse noxious inhibitor pain suppression

·         Releases local & systemic neurotransmitters

·         Signals the brain and influences autonomic regulatory processes

·         Increases blood flow and relaxes muscles

The following section is a brief technical review of some of the modern scientific literature regarding the effects of acupuncture.  Most are animal studies.

Pain Relief Mechanisms

Certain acupuncture points, including Large Intestine 4, release endogenous opioids or morphine-like chemicals that the body makes such as  b endorphin, enkephalin, and dynorphin. This provides systemic analgesia and pain relief throughout the body which takes 15-20 minutes to develop. [2]

Diffuse noxious inhibitory controls and gate control theory mechanisms reduce pain sensation while the stimulus (i.e. the needle) is applied. This occurs with acupuncture point Stomach 36[3] and probably to any ashi (“ah shir”) or tender point. You experience this phenomenon when bump your elbow and it hurts less when you rub it.

Polymodal receptors are nociceptors (pain receptors) which respond to mechanical, thermal and chemical stimuli. These release a variety of neuropeptides which serve as local neurotransmitters. Polymodal receptors are thought to be related to the qi sensation many patients feel with properly inserted acupuncture needles.[4]

Dopamine and serotonin, two well known systemic neurotransmitters, are released at acupuncture points including Urinary Bladder 23, Stomach 36, and Du 20.  These neurotransmitters affect pleasure and reward systems in the median fore-brain bundle and promote relaxation and a sense of well-being which may contribute to pain relief.[5]

Changes in Autonomic Functions

Needling of local or ashi points in leg muscles have been demonstrated to increase blood flow in muscles which leads to decreased inflammation and increased healing.   The mechanisms for increasing blood flow were not determined.[6]

Acupuncture in the lumbar region was shown to increased blood flow to the sciatic nerve and relieve numbness and pain of lower limb.[7]

In a human study, acupuncture points Pericardium 6, Stomach 25, Stomach 21, and Ren 12 have been shown to inhibit acid, enzyme and gastrin secretion, reduce  dysrhythmias, and decrease gastric motility. Nausea and vomiting are characterized by irregular GI contractions.  These points are traditionally used to treat nausea and vomiting. [8]

Neurology and Brain Architecture

Recent Functional MRI studies[9]^,[10] have been performed where the brain is imaged during insertion of a needle and stimulation of an acupuncture point.  Acupuncture stimulates a signal that is transmitted to a specific part of the brain or spinal column which then shows activity in the fMRI image.

This activity in the central nervous system then regulates a function or homeostatic process in the body.  Examples are given in the following table.