Acupuncture is a complementary medical practice that entails stimulating certain points on the body, most often with a needle penetrating the skin, to alleviate pain or to help treat various health conditions.
Developed millennia ago in China, numerous recent studies conducted by scientists in Europe and the United States have found that acupuncture is at least moderately effective in treating pain and nausea.
For example, one of the largest studies to date on acupuncture and chronic pain — a meta-analysis of 29 well-conducted studies involving nearly 18,000 patients and published in October 2012 in the Archives of Internal Medicine — found that acupuncture is effective for treating chronic pain and therefore is a reasonable referral option. The doctors wrote that "[s]ignificant differences between true and sham acupuncture indicate that acupuncture is more than a placebo" but added that "these differences are relatively modest."
Researchers are also conducting studies to determine if acupuncture is effective at treating depression, anxiety and a variety of cancer and cancer treatment-related symptoms, according to Dr. Ting Bao, an integrative medical oncologist at Memorial Sloan-Kettering Cancer Center in New York.
Most doctors outside of the practice of traditional Chinese medicine are not convinced that acupuncture can treat specific diseases, such as diabetes or liver or kidney diseases, as is prescribed by some practitioners in China, according to Bao, who focuses on the use of acupuncture as a complementary treatment for breast cancer patients.
"Right now acupuncture is really used to alleviate cancer treatment-induced side effects or cancer-induced symptoms, but never to directly treat cancer," Bao told Live Science. "It would be really interesting to see if acupuncture can help prevent cancer. But I don't think the research has reached that level yet."
How acupuncture is said to work
Acupuncture dates back to at least 100 B.C., which is when an organized system of diagnosis and treatment using needles was first described in writing in China. However, the practice likely precedes this written history, according to Dr. Edzard Ernst, a research physician specializing in the study of complementary and alternative medicine.
But the modern practice of acupuncture has changed considerably since it was first introduced in China, according to David W. Ramey and Bernard E. Rollin, who describe the evolution of acupuncture in their book "Complementary and Alternative Veterinary Medicine Considered" (Wiley-Blackwell, 2003). By the 18th century, acupuncture looked much different than the practices described in ancient Chinese texts. And by the early 20th century, aspiring doctors at the Chinese Imperial Medical Academy no longer studied acupuncture, according to the authors.
However, during the so-called Great Leap Forward of the 1950s and the Cultural Revolution of the 1960s, China's communist leader, Mao Zedong, began actively promoting acupuncture and other traditional medical treatments as "pragmatic solutions to providing health care to a vast population that was terribly undersupplied with doctors," the authors write. There is no evidence to suggest that this revival of the ancient practice of acupuncture resulted in improved health for Chinese citizens, according to the authors.
In traditional Chinese medicine, acupuncture is linked to the belief that disease is caused by disruptions to the flow of energy, or qi, in the body. Acupuncture stimulates points on or under the skin called acupuncture points or acupressure points, releasing this qi. The qi then travels through channels called meridians, according to the Center for Spirituality & Healing at the University of Minnesota.
But the acupuncture treatments carried out in hospitals and other health care facilities in the West today are not based on the same principles that were established in ancient Eastern texts, according to Bao. Western scientists have been trying to study the mechanism of acupuncture for years and have come up with several hypotheses, she said.
"One major hypothesis is that acupuncture works through neurohormonal pathways. Basically, you put the needle through specific points in the body and stimulate the nerve. The nerve actually sends signals to the brain, and the brain releases neural hormones such as beta-Endorphins. By doing that, the patient may feel euphoric, or happy, and this increases the pain threshold and they feel less pain," Bao said.
Another hypothesis is that acupuncture works by reducing pro-inflammatory markers, or proteins, in the body. Some animal and human studies suggest that by doing acupuncture, you can significantly decrease these pro-inflammatory markers — including TNF and IL-1β — which decreases inflammation and reduces pain, Bao said.
Yet another hypothesis applies specifically to how acupuncture can be used to treat nerve damage, such as chemo-induced peripheral neuropathy, a condition that often causes numbness or weakness in the feet and hands.
"The idea is that by putting the needle in, you stimulate the brain to secrete some nerve growth factor, and then that helps the nerve to regenerate," Bao said.
Limitations and misconceptions
Increasingly, mainstream doctors and medical institutions are accepting the practice of acupuncture, particularly for treatment of pain and nausea. A 2013 review, for example, found that acupuncture could reduce vomiting and nausea among patients receiving chemotherapy, according to Cancer Research UK.
Research is ongoing into whether acupuncture can also help with other cancer treatment-related symptoms, including hot flashes, peripheral neuropathy and lymphoedema (swelling of the arm or hand), according to Bao.
The World Health Organization maintains an extensive list of diseases and conditions (mostly pain related) possibly treatable by acupuncture. Many doctors now do not discourage their patients from receiving acupuncture when conventional medicine fails them or when convention treatment entails too many adverse side effects.
There is a growing body of research exploring whether acupuncture also can be used to treat depression, sleep disturbances and drug addiction. In general, however, acupuncture is considered complementary to conventional treatments, and it is likely most effective when implemented along with certain healthy lifestyle habits, according to Bao.
"Usually, when people are more health conscious, they pay attention to diet, they exercise more, they think about a mind-body approach to decrease stress, and they might also use acupuncture. Ideally, I think these things should all come together, rather than having the goal be to use acupuncture to treat everything. That doesn't necessarily work," Bao said.
Additional reporting by Christopher Wanjek, Live Science Contributor