After more than 3,000 clinical trials of acupuncture, many skeptical scientists are convinced that despite the benefits that patients might think they experience, the whole thing is simply a highly convincing placebo effect.

Just like they do with drugs, scientists test whether acupuncture works against a placebo, which most often is placing needles at non-acupuncture points. The key test is the difference between the two: if both groups report the same level of pain relief, it is concluded that the treatment being tested doesn’t work.

But a new generation of brain imaging studies is suggesting that perhaps researchers need to refine their testing methods. There are now several trials showing that even when patients in acupuncture and placebo groups report similar drops in pain, the effects of treatment can be very different.

For example, Richard Harris, a neuroscientist at the University of Michigan, used brain scans to see whether acupuncture triggers an endorphin release the same way that placebos do. They gave fibromyalgia patients either true or sham acupuncture and then scanned their brains using a PET scan.

PET scans can’t see endorphins directly, but can detect the opioid receptors that these opiates target. Opioid receptors are present on the surface of nerve cells in the brain and other areas. When “locked” by endorphins, or other opioid molecules like morphine, they prevent the cells from sending pain signals. In Harris’ experiment, a drop in the number of free, or unlocked, receptors in the patient’s brains would indicate that endorphins had been released.

Both the true and sham acupuncture groups reported a similar reduction in pain after treatment. In the sham group, the PET scans did indeed show fewer free opioid receptors in areas of the brain associated with pain regulation, suggesting that pain relief was caused by endorphins.

In the true acupuncture group, something surprising occurred. Instead of showing the same results as the sham group, the number of free opioid receptors in the brains of the true acupuncture group didn’t reduce, but they increased dramatically. This would suggest that true acupuncture, in addition to achieving endorphin-mediated release pain relief, also causes an increase in the number of opioid receptors that are expressed on the cell wall of the neurons in the brain.

It’s been shown that chronic pain sufferers have fewer opioid receptors than healthy, pain-free people, leaving them less responsive to endorphins and overly sensitive to pain. If acupuncture reverses that scenario and can restore normal opioid receptivity, that would go far in explaining another way acupuncture helps with pain. And it could lead to a reversal of disease processes like those in fibromyalgia. It would also explain why people taking prescription opioids who receive acupuncture need less of their medicine. If there are more opioid receptors cell available on the cell wall, the cell becomes more efficient in binding the opioids and turning off the pain signal.

More recently, a study at Harvard Medical School a study focused on carpal tunnel syndrome pain using electro-acupuncture as treatment found that again the sham and true acupuncture groups reported similar reductions in their symptoms immediately after treatment. But in this trial, only the true group showed measureable improvements in the speed of nerve conduction in the wrist and hand, and in the pain regulating parts of the brain. And only the true group still had reduced pain after 3 months.

It is taking time, but a mountain of evidence is building that attests to the efficacy of acupuncture, so much so that soon even the most skeptical scientist won’t being able to deny the many wonderful benefits of this ancient medicine.

Happy New Year!