Researchers at Georgetown University Medical Center have found that acupuncture reduces the levels of a protein-like substance in rats linked to chronic stress.
If replicated in humans, acupuncture could offer a therapy for stress, which is often difficult to treat.
“It has long been thought that acupuncture can reduce stress, but this is the first study to show molecular proof of this benefit,” said the study’s lead author, Ladan Eshevari, Ph.D., an assistant professor.
Eshkevari, a certified acupuncturist, conducted the study because many of the patients she treats with acupuncture reported a “better overall sense of well-being — and they often remarked that they felt less stress.”
While the World Health Organization states that acupuncture is useful as adjunct therapy in more than 50 disorders, including chronic stress, Eshevari said that no one has biological proof that it does so.
She designed a study to test the effect of acupuncture on blood levels of neuropeptide Y (NPY), a peptide that is secreted by the sympathetic nervous system in humans. This system is involved in the “flight or fight” response to stress.
Rats are often used to research the biological determinants of stress because they mount a stress response when exposed to winter-like cold temperatures for an hour a day.
Eshevari allowed the rats to become familiar with her, and encouraged them to rest by crawling into a small sock that exposed their legs. She conditioned them to become comfortable with the kind of stimulation used in electroacupuncture — an acupuncture needle that delivers a painless, small electrical charge.
This form of acupuncture is a little more intense than manual acupuncture and is often used for pain management, she said, adding “I used electroacupuncture because I could make sure that every rat was getting the same treatment dose.”
She then selected a single acupuncture spot to test: Zuslanli (ST 35 on the stomach meridian), which is said to help relieve a variety of conditions, including stress. That acupuncture point for rats — and humans — is on the leg below the knee.
The study, published online in December in Experimental Biology and Medicine, utilized four groups of rats for a 14-day experiment: A control group that was not stressed and received no acupuncture; a group that was stressed for an hour a day and did not receive acupuncture; a group that was stressed and received “sham” acupuncture near the tail; and the experimental group that were stressed and received acupuncture to the Zuslanli spot on the leg.
She found NPY levels in the experimental group came down almost to the level of the control group, while the rats that were stressed and not treated with Zuslanli acupuncture had high levels of the protein.
In a second experiment, she stopped acupuncture in the experimental group but continued to stress the rats for an additional four days, and found NPY levels remained low. “We were surprised to find what looks to be a protective effect against stress,” she said.