A federal panel yesterday concluded for the first time that the ancient Chinese art of acupuncture is an effective treatment for certain kinds of pain and nausea and shows promise for a variety of other conditions, providing an unprecedented endorsement by the Western medical establishment.

The panel, convened by the National Institutes of Health, has no binding power over doctors or insurers. But health policy experts said it would almost certainly increase the number of patients opting for treatment by the nation's 10,000 acupuncturists, and could eventually lead to greater coverage of acupuncture by insurance companies and government programs such as Medicare and Medicaid.

More generally, the statement represents a landmark expression of open-mindedness to the possibility that medical systems completely alien to scientific convention -- including the Chinese medical model, which posits the existence of invisible "energy meridians" in the body -- may have something to offer Western patients.

"It's a very difficult task to take a completely different system of medicine, transplant it to a system of Western medicine, and ask, Does it work?' " said David J. Ramsay, president of the University of Maryland at Baltimore and chairman of the NIH panel. "But we did decide that in a number of situations, it really does work."

Specifically, the panel concluded there is "clear evidence" that acupuncture is an effective treatment for nausea and vomiting caused by cancer chemotherapy drugs, surgical anesthesia or pregnancy, and for pain following dental surgery. The group said there was weaker evidence that acupuncture may be effective against other conditions, including menstrual cramps, tennis elbow, the generalized muscle pain known as fibromyalgia, drug addiction, stroke and headache.

Equally important, Ramsay said, acupuncture "has fewer side effects and it's less invasive than many other things we {doctors} do." Given its good safety profile and the fact that it is often less expensive than Western medicine, "it's time to take it seriously."

Advocates of acupuncture, about 1,000 of whom attended the three-day Bethesda meeting that concluded with yesterday's "consensus statement," gave the panel a standing ovation as Ramsay finished presenting the group's final report.

"It's a very positive statement," said David Blaiwas, president of the Maryland Acupuncture Society. "I think it will open a lot of doors."

Critics bristled at the report, however. "What the proponents present as evidence is in fact delusion, and if the reviewing body is incapable of separating the two then shame on them," said Victor Herbert, a professor of medicine at Mount Sinai School of Medicine in New York and a long-standing critic of alternative medicine. Herbert traveled to China several years ago to investigate what he calls "quackupuncture" and concluded that it is largely a matter of hypnotic suggestion.

Acupuncture has been used in China for at least 2,000 years, but was not introduced to the West until 1971, when a New York Times reporter covering Nixon's historic visit to that country underwent emergency surgery and wrote about its use to quell his post-surgical pain. Practitioners insert needles that are as fine as a human hair into specific points on the body, then twirl them and leave them there for 20 to 30 minutes.

The art is essentially empirical, meaning it is the result of centuries of seeing what worked. Traditional practitioners believe that illness results from imbalances of bodily energy, called Qi (pronounced "chee"), which can be corrected by using needles to open hidden channels or meridians in the body.

Acupuncture has grown enormously popular in the United States in recent years. In 1993, the Food and Drug Administration determined that more than 1 million Americans were spending a total of about $500 million a year on the practice. Others estimate that up to 15 million Americans have tried acupuncture at least once. Treatments typically cost about $100.

Despite lingering questions about its efficacy, acupuncture has gradually entered the medical mainstream in this country. Many states have accredited licensure programs and some insurance companies already pay for treatments. Moreover, more than 3,000 medical doctors now use acupuncture in their practices, and up to 1,000 U.S. drug addiction treatment facilities offer acupuncture as part of their programs.

Disturbed by the gap between acupuncture's popularity and proof that it works, the NIH Office of Alternative Medicine organized the NIH panel of experts in medicine, anthropology, biostatistics, epidemiology and other scientific and cultural disciplines. The panel concluded that most research on acupuncture is of poor quality and that no one knows how it might work.

But it found well-conducted studies indicating that acupuncture could cut by 50 percent the number and severity of episodes of nausea in surgical patients recovering from general anesthesia, and similar results for patients getting cancer drugs or suffering from the "morning sickness" of pregnancy.

In the dental study, those who received acupuncture before the removal of impacted molars had an average of 17 minutes of post-surgical pain, compared to 94 minutes for those treated with conventional drugs.

The panel said acupuncture seemed not to help people quit smoking, and its usefulness remained inconclusive for most of the other ailments it looked at. It called for improved funding for acupuncture research.

Much of the panel's public deliberations were as much a critique of conventional medicine and Western science as they were an assessment of acupuncture. The audience frequently cheered as experts noted that many Western medical practices are as lacking in proof of efficacy as is acupuncture. Many also were pleased to hear panelists voice criticisms of randomized controlled clinical trials, widely considered the gold standard of modern medical practice but criticized by some proponents of alternative medicine as unrepresentative of everyday life.

"People don't care if it works in a controlled setting," said Daniel C. Cherkin, an investigator at the Group Health Center for Health Studies in Seattle. "They care if it works for them in the real world."