|MadSci Network: Medicine|
What a great question! No only does no-one really know the answer, but culturally based beliefs even change what evidence can be used to answer it.
Acupuncture is a technique used in Asian medicine that was developed over two thousand years ago. Modern acupuncture in the U.S. uses different methods that incorporate medical traditions from China, Japan, Korea, and other countries.The theories of acupuncture sound very arcane to many Americans, including me.
The concept of 'energy flow' or Qi, foreign to American medicine, is central to the theory behind acupuncture. American research studies that have looked at whether acupuncture is an effective treatment and how it works do not consider the concept of Qi. Whether this research is missing a central component of health or moving an ancient method into the 21st century is unclear. If the Asian theory of acupuncture is correct, Qi is a basic component of health. If the American theory of acupuncture is correct, acupuncture interacts with known body systems. To some extent, what is known about acupuncture depends on the premise with which you start.
If you start on the premise that acupuncture works by affecting body systems known in Western medicine, you would want to know that studies in animals and humans have shown that acupuncture causes biological responses. These responses can occur at or close to the site of application, or at a distance. Sensory nerves stimulated by acupuncture change their signaling to structures within the central nervous system, which can change the activiy of different physiological systems. Alteration in the secretion of brain chemicals and hormones, and changes in blood flow have been documented. There is also evidence of alterations in immune functions produced by acupuncture. Studies show that the analgesic effects of acupuncture are at least partially explained by acupuncture's triggering release of pain reliving chemicals in the body called optiod peptides. Acupuncture may also activate the hypothalamus and the pituitary gland, resulting in a broad effects in the body.
Acupuncture has become widely accepted treatment. The National Institutes of Health (http://www.nih.gov) has funded research on it. The Food and Drug Administration recently removed acupuncture needles from the category of "experimental medical devices". The World Health Organization lists medical conditions that may benefit from the use of acupuncture.
If you start on the premise that acupuncture works by affecting Qi, the evidence is different. The first medical texts containing concepts included in present-day acupuncture date back to the third century B.C. At that time a soft woolly mass prepared from the young leaves of Asian wormwoods were ignited on the skin, called moxibustion. This affected one of the 11 identified acupuncture channels. Each channel was associated with specific symptoms. Some channels are even named after their symptomatic focus. For example, the Large Intestine Meridian is called 'the tooth meridian'. I do not understand how this works, and cannot evaluate whether Asian medicine in the third century B.C. was more or less advanced than European medicine at that time. One of the main differences seems to be that Asian medicine emphasized an imbalance of the body's own properties as a source of illness, while European medicine emphasized the body being invaded by foreign sources of illness.
Acupuncture has been used as anesthesia as well. I cannot evaluate the statements made to support this, but here are some of them. "Acupuncture interrupts the reception and interpretation of nerve stimulus as pain." "The nerve through which the pain signals travel from the knee area to the brain is called the tibial nerve. It travels from near the groin down to the knee. We applied needles to two points along that pathway. These needles were attached to an electro-stim machine. This is a small little electronic unit that emits very slight bursts of electricity to the needles. These little electric signals over stimulate the nerve without any pain. When the nerve is over stimulated, it is unable to transmit any other sensations, such as the pain associated with the surgery"
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