Acupuncture has been used in Eastern medicine for hundreds of years as a way to relax patients and relieve illness. It is historically believed to "restore the flow of energy." But new research into the mechanisms of how acupuncture works shows that it may induce real physiological changes.

Researchers at the Georgetown University Medical Center found that in laboratory rats electronic acupuncture stimulation resulted in the reduction of a key stress hormone.

"Many practitioners of acupuncture have observed that this ancient practice can reduce stress in their patients, but there is a lack of biological proof of how or why this happens," said the study's lead author, Ladan Eshkevari, PhD, an associate professor of nursing at Georgetown University's School of Nursing and Health Studies, a part of GUMC. "We're starting to understand what's going on at the molecular level that helps explain acupuncture's benefit."

Rats were chosen because they are used in medical research to test stress responses. They start exhibiting stress responses when exposed to cold air temperatures for just one hour a day. The research was conducted over a period of 10 days and consisted of groups that had been stressed, a group that had been stressed and received acupuncture therapy, a group stressed that received a mock acupuncture therapy and a group that just received the acupuncture with no stress.

The spot chosen for the acupuncture was the Zusanli spot on the leg which has been reported to relieve stress and stress related symptoms. The spot is below the knee in people and the same spot exists in mice.

The examination of stress hormones focused on hypothalamus pituitary adrenal (HPA) axis, which includes hormones produced by three important glands. Hormones from these glands influence stress, the immune system, digestion, mood, emotion, sexuality and energy expenditure.

Researchers also looked at the presence of a peptide called NPY which is released by the nervous system in humans and rodents and is involved in the flight or fight response.

"We found that electronic acupuncture blocks the chronic, stress-induced elevations of the HPA axis hormones and the sympathetic NPY pathway," Eshkevari said.  "Our growing body of evidence points to acupuncture's protective effect against the stress response."

The research published in the journal Endocrinology can be found here