NEW YORK (Reuters Health) – Acupuncture may bring relief to some people with chronic lower back pain — though whether the effects are physical, psychological or both remains unclear, researchers reported Monday.

In a study of 638 adults with stubborn back pain, investigators found that patients who received acupuncture for seven weeks generally showed greater improvements in pain and function than those given standard medical care, like medication or physical therapy.

However, the benefits were seen in both patients who underwent real

acupuncture and those who (unknowingly) underwent a simulated version

— in which the researchers used toothpicks to touch, but not pierce, the skin.

The findings raise questions about the nature of acupuncture’s benefits, the researchers report in Monday’s issue of the Archives of Internal Medicine.

Both real and simulated acupuncture may produce true physiological effects that ease pain, according to lead researcher Dr. Daniel C.

Cherkin, the lead investigator from the Center for Health Studies in Seattle.

But both could also work through a placebo effect — meaning that people’s symptoms improve because they believe the therapy will work.

“It is quite possible that both of these explanations contributed to the observed benefits of acupuncture,” Cherkin told Reuters Health.

Acupuncture has been used for more than 2,000 years in Chinese medicine to treat a wide variety of ailments. According to traditional medicine, specific acupuncture points on the skin are connected to internal pathways that conduct energy, or qi (“chee”), and stimulating these points with a fine needle promotes the healthy flow of qi.

Modern research has suggested that acupuncture may help ease pain by altering signals among nerve cells or affecting the release of various chemicals of the central nervous system.

For their study, Cherkin and his colleagues recruited patients who’d been receiving conventional treatment for chronic lower back pain.

They randomly assigned the patients to either continue with standard care or start one of three acupuncture treatments: standard acupuncture (needle placement into the acupuncture points most commonly used for back pain); “individualized” acupuncture, in which therapists could choose the acupuncture points they used for each patient; or simulated acupuncture.

After eight weeks, patients in all three acupuncture groups were, on average, faring better than those in the standard-care group. An extra one in five had significant improvements in daily functioning, and their pain had eased to a greater degree.

At the one-year mark, acupuncture patients were still reporting better functioning, though the difference in pain had faded; 59 percent to 65 percent of acupuncture patients were showing “clinically meaningful”

improvements in their daily functioning, versus 50 percent of the patients in the usual-care group.

Whatever the reasons for the acupuncture patients’ improvements, the findings add to evidence that the therapy is a “reasonable treatment option” for people with chronic back pain, Cherkin said.

He stressed, though, that like all treatments for back pain, acupuncture will not work for everyone.

“Our study estimates that it makes a substantial difference in the lives of about 20 percent of those who try it,” Cherkin said.

SOURCE: Archives of Internal Medicine, May 11, 2009.