Physiological Effects of Acupuncture

The National Institute of Health (NIH) states that “studies have demonstrated that acupuncture can cause multiple biological responses, mediated mainly by sensory neurons, to many structures within the central nervous system. This can lead to activation of pathways, affecting various physiological systems in the brain, as well as in the periphery.”

NIH also suggests that acupuncture “may activate the hypothalamus and the pituitary gland, resulting in a broad spectrum of systemic effects. Alteration in the secretion of neurotransmitters and neurohormones, and changes in the regulation of blood flow, both centrally and peripherally, have been documented. There is also evidence of alterations in immune functions produced by acupuncture.”

Current Theories on the Mechanism of Acupuncture

Neurotransmitter Theory - Acupuncture affects higher brain areas, stimulating the secretion of beta-endorphins and enkephalins in the brain and spinal cord. The release of neurotransmitters influences the immune system and the antinociceptive system.

Autonomic Nervous System Theory - Acupuncture stimulates the release of norepinephrine, acetylcholine, and several types of opioids, affecting changes in their turnover rate, normalizing the autonomic nervous system, and reducing pain.

Gate Control Theory - Acupuncture activates non-nociceptive receptors that inhibit the transmission of nociceptive signals in the dorsal horn, “gating out” painful stimuli.

Vascular-interstitial Theory – Acupuncture manipulates the electrical system of the body by creating or enhancing closed-circuit transport in tissues. This facilitates healing by allowing the transfer of material and electrical energy between normal and injured tissues.

Blood Chemistry Theory – Acupuncture affects the blood concentrations of triglycerides, cholesterol, and phospholipids, suggesting that acupuncture can both raise and diminish peripheral blood components, thereby regulating the body toward homeostasis.