Does Acupuncture Work?


How Acupuncture Works: A Biomedical Overview 

In biomedical terms, acupuncture is a needling technique that restores internal homeostasis. As Christian Nix and Paul Raford state, acupuncture accomplishes this by “down-regulating a hyperactive sympathetic nervous system, thus disrupting and modulating the stress response”.

A hyperactive system has a number of adverse effects, such as:

  • Increased blood pressure and heart rate
  • Increased emotional and physical stress
  • Decreased heart rate variability
  • Decreased blood flow to digestive organs and soft tissue
  • Impaired cognition from irregular sleep

In turn, down-regulating a hyperactive system can help:

  • Reduce blood pressure and heart rate
  • Increase blood flow and repair muscles
  • Reduce emotional and physical stress
  • Fight the symptoms of depression and anxiety
  • Promote overall feelings of wellness
  • Improve sleep patterns

Acupuncture also stimulates nerves to release a number of chemicals that can aid in muscle repair, pain relief, stress relief, and an overall sense of wellbeing.

How acupuncture repairs muscles 

One way the body responds to acupuncture involves a process of nerve stimulation known as “axon reflex”. Acupuncture needles are used to stimulate the skin and muscles, which causes chemicals, such as calcitonin gene related peptide (CGRP) and ATP, to be released. Because CGRP is a vasodilator, this chemical dilates blood vessels, thereby increasing oxygen-rich blood flow to the immediate area. In turn, this fuels tissue and muscle repair, and effectively helps aid in the recovery of musculoskeletal conditions.

Acupuncture and pain relief

Acupuncture can help relieve pain by blocking pain messages through a process referred to as the ‘segmental effect’. By gently stimulating specific points on the body, acupuncture triggers nerve signals to a portion of the spinal cord called the dorsal horn. This causes local cells to release the body’s own pain-suppressing mechanisms, such as a chemical called encephalin, which blocks further stimulation of the nerve. Since nerves supply large portions of the body, such as organs and muscles, blocked stimulation of one nerve will help block pain messages coming from a much wider area of the body.

Acupuncture for stress, anxiety, and depression

Nerve stimulation occurring through acupuncture will also propagate up from the spinal cord and into the brain. This influences many portions of the brain, including the limbic system, or the emotional center of the brain, thereby enhancing production of ‘feel good’ hormones such as adrenocorticotropic hormone (ACTH), endorphins, oxytocin, serotonin, and norepinephrine.

The release of endorphins and oxytocin may be an important component as to why many patients describe their experience as sedating, calming, and relaxing.

Acupuncture not only regulates body’s stress response but may also fundamentally recalibrate aspects of the primary Central Nervous System responsible for symptoms and severity of anxiety and depression.

Does Acupuncture Work?

You hear the term “acupuncture,” and visions of needles may dance in your head. But the 3 million Americans (and counting) who have tried it know there’s a lot more to the treatment than pokes and pricks.

A typical visit to an acupuncturist might begin with an examination of your tongue, the taking of your pulse at several points on each wrist and a probing of your abdomen. “They didn’t have MRIs or X-rays 2,500 years ago, so they had to use other means to assess what’s going on with you internally,” says Stephanie Tyiska, a Philadelphia-based acupuncture practitioner and instructor.These diagnostic procedures inform the placement of the needles, Tyiska says. But a visit to an acupuncturist could also include a thoughtful discussion of your diet and personal habits, recommendations to avoid certain foods or to take herbal supplements and an array of additional in-office treatments—like skin brushing or a kind of skin suctioning known as “cupping”—that together fall under the wide umbrella of traditional Chinese medicine.But does it work? Figuring out whether each one of these practices may be therapeutically viable is a challenge, and determining how all of them may work in concert is pretty much impossible. Combine them with acupuncturists' frequent references to “qi,” or energy flow, and it’s easy for a lot of people to dismiss the practice as bunk. 

Not so fast, though. A recent meta-analysis, which examines existing research on a topic, compared acupuncture treatment to standard medical treatment (the kind involving a doctor’s exam and drugs) for musculoskeletal pain, chronic headaches, and osteoarthritis. It also compared real acupuncture to “sham” acupuncture, a procedure where needles are inserted at random to make patients believe they were receiving acupuncture when they were not. “There are many poorly designed acupuncture studies out there, so we tried to include only the best trials,” says Andrew Vickers, a biostatistician at Memorial Sloan Kettering Cancer Center who coauthored the meta-analysis.When comparing legit acupuncture to standard care, there was a statistically significant benefit to acupuncture, Vickers says. “We saw a measurable effect there,” he explains. “If acupuncture were a drug, we’d say the drug works.”When Vickers and his team compared legitimate acupuncture to sham acupuncture, that benefit persisted, but shrank. There are a lot of ways to interpret this, Vickers says. “It could be acupuncture has a large placebo effect, or it could be that pressure points”—the precise locations at which needles are inserted—“are less important than acupuncturists claim,” he explains.

Many people equate placebo effects with scams. “The term placebo has always had this very negative connotation,” says Vitaly Napadow, director of the Center for Integrative Pain Neuroimaging at Harvard Medical School. But Napadow says our poor opinion of placebo needs revising. The human body has built-in systems for stoking or calming pain and other subjective sensations. “If a placebo can target and modulate these endogenous systems, that’s a good and a real thing,” he says.

But acupuncture may have effects even more profound than placebo. Napadow has conducted dozens of brain imaging studies on acupuncture in an effort to determine just how the treatment may or may not calm pain or related conditions like headache or arthritis. He says there are lots of ways acupuncture might work, and the specific mechanism may depend on the type of condition you're trying to treat.

One possibility is that being jabbed with a needle induces a tiny injury, causing your immune system to respond by sending inflammatory proteins and other infection-fighting, would-healing chemicals to the source of that injury. “There’s the idea that by inducing many of these very small injuries, you’re ramping up the immune system so that it can deal with bigger problems,” Napadow says.

It’s also possible that the increased flow of blood and immune system chemicals to the poke site could help clear away accumulated cellular byproducts that may trigger or worsen a condition like plantar fasciitis or tendonitis, he says. “Or the needles might activate nerve receptors in the skin, which then pass info up into your spinal cord and brain,” he says. “That information might trigger a change in brain physiology, like the release of endorphins or those sorts of neurotransmitters that could lessen the sensation of pain associated with something like fibromyalgia.

”His research has borne out some of these potential mechanisms. One of his studies showed that after traditional acupuncture, opioid receptors were more available, or receptive, to the body's natural pain-quelling chemicals . There was no such change after sham acupuncture.

It basically means opioid receptors were more available or receptive to the types of body hormones and chemicals that help quell pain. 

Napadow says that more research has looked into the effect of expectancy on acupuncture outcomes—or whether people who believe the treatment will work experience more benefit than those who don’t. The evidence suggests that expectancy doesn’t improve acupuncture’s effectiveness. “Often it’s the guy who says his wife made him try it who has the greatest benefit,” he says.

Couple these promising findings with the fact that acupuncture is a low-cost treatment option with very few side effects, and Napadow says it makes sense to consider it a helpful partner to Western medicine—especially when it comes to chronic pain-related ailments for which Western medicine often relies on painkillers. “It won’t cure cancer,” he says. “But it could be effective for managing side effects of radiation or chemotherapy—things like pain or neuropathy or nausea.

”Tyiska, the Philadelphia-based acupuncturist, makes a similar argument. “I don’t tell people to stop seeing their doctors,” she says. “But if you’re being prescribed opioids, or you’re considering surgery, you lose very little by trying acupuncture first.”


How Acupuncture Tamps Down Stress

Acupuncture may work by targeting the same pathways that stress travels along, according to a new study in rats from Georgetown University Medical Center and published in the journal Endocrinology.

Ladan Eshkevari, PhD, a nurse anesthetist, licensed acupuncturist and associate professor in the department of nursing and the department of pharmacology and physiology at Georgetown University Medical Center, noticed that the acupuncture patients coming to her for pain were reporting improvement of symptoms unrelated to their pain, like chronic stress, depression, sleep and appetite.

"There was nothing in the literature about acupuncture for PTSD and chronic stress," she says, so she decided to study it. To find out if acupuncture was affecting chronic stress, Eshkevari and a team of researchers looked at what happened in a key pathway in dealing with stress for both humans and rats: the hypothalamus-pituitary-adrenal axis (HPA). It's the same pathway targeted by some anti-anxiety drugs and antidepressants, Eshkevari says, and the HPA is involved in the production of the stress hormone cortisol.

In the experiment, the researchers compared four groups of rats: one group was stressed and given acupuncture; another group was stressed and given sham acupuncture (at a non-acupuncture point to make sure any results weren't due to a placebo effect); a third group was stressed and didn't get any acupuncture; and a final control group just hung out without any interventions.

First, the researchers decided to look at an acupuncture point called stomach 36; according to Chinese medicine, it’s a potent point associated with stress, stomach issues and pain, and in humans, it’s located right below the knee behind the tibia bone. The rat equivalent of stomach 36 is on the hind paw near the knee, Eshevari says.

Because most people who get acupuncture come in for treatment after a stressful event, Eshkevari says, she wanted to expose the rats to stress before treatment. She put them in a bucket of ice that made their legs cold for about an hour, then let the rats acclimate to room temperature before their 20-minute-long acupuncture sessions.

“It took me months to figure out how to do acupuncture on an awake rat,” says Eshkevari. It would have been easier to anesthetize them, but Eshkevari didn’t want to affect stress hormone levels. So she cut up her husband’s tube socks to hold the rats during treatment. “It was only big enough for them to crawl in to their hind legs, so their hind paws would be hanging out,” she says. She put the rats in the socks, quickly inserted the needles and connected them to the electrodes for their 20-minute sessions.

After 11 days of stress and acupuncture, Eshkevari put the rats to the test. When placed in an open box, less anxious rats will more readily explore; anxious rats will sit in the corner. And in a forced swim test, rats are dropped in a bucket and forced to swim; the quicker they give up, the higher they score in depression.

The rats who had acupuncture at the stomach 36 point had levels of cortisol in their blood comparable to the control rats that weren't stressed—and lower cortisol levels than the other stressed-out rats, including the rats who received sham acupuncture. Likewise, the stressed-out rats who didn't receive acupuncture showed more anxiety, depression and hopelessness through the behavioral tests, while the acupuncture-treated rats behaved a lot more like the normal rats that hadn't been exposed to anything, Eshkevari says. "In this model, acupuncture can allay some of the untoward effects of stress," she explains.

To make sure the acupuncture was affecting the pathway they thought it was, the researchers gave the rats a drug to block the HPA pathway, then retested the rats of behavioral measures. The effect went away.

“That’s how we know that the acupuncture not only worked, but it worked via the pathway we’re hypothesizing it works,” Eshkevari says.

The study is in rats, not in humans, and Eshkevari says that it's certainly not enough to prove that the mechanism works exactly the same way in humans. "It would be very interesting and much more useful to do these experiments on human models of stress," she says.

Still, she believes it's an important preliminary step. "I had a sense anecdotally from the patients," she says. "Now I feel like we have some evidence that this does work, the placebo is controlled for, and when we block the pathway it stops working. We know this is a potential mechanism. Now I can more confidentially try to translate that to humans." 

Acupuncture Actually Works for Neck Pain

Two alternative therapies get a boost of scientific legitimacy in a new study published in the Annals of Internal Medicine.

Acupuncture, the ancient practice of needle insertion, and the Alexander Technique, a program that teaches people how to avoid unnecessary muscle tension throughout the day and improve posture, coordination, balance and stress, are two complementary therapies often used to help treat neck pain. Treating it is often difficult, and it’s common for people to seek out alternative therapies.

The researchers wanted to see how well two of these worked. They assigned 517 people, all of whom had neck pain for at least three months (and sometimes many years), to the standard care for neck pain, which involves prescription medications and physical therapy. Some of the patients were assigned to also receive one of two extra treatments: a dozen 50-minute acupuncture sessions or 20 private Alexander Technique lessons—which focus on teaching people how to move their body to avoid or correct muscular pain.

A year after the start of the study, people in the groups doing acupuncture and the Alexander Technique had significant reductions in neck pain—pain was assessed by questionnaire—compared to those who just got usual care. Both groups reported about 32% less pain than they had at the start of the study, which is far greater than the 9% typically associated with physical therapy and exercise. The interventions also gave people in the groups more self-efficacy, which were linked to better pain outcomes.

The study adds to growing evidence suggesting that acupuncture is effective against pain; a landmark review in 2012 involving almost 18,000 people with chronic pain concluded that acupuncture was better than standard care and sham acupuncture (which proved the effect is not due to placebo of simply sticking needles in the body.)

"You get a two-fold effect with acupuncture for pain: a natural pain-relieving effect and an anti-inflammatory effect," says Jamie Starkey, lead acupuncturist at Cleveland Clinic’s Center for Integrative Medicine, who was not involved in the new study.

Acupuncture manipulates the nervous system, she says, activating the release of pain-relieving endorphins. "With neck pain patients, a lot will get steroid injections or take a non-steroidal anti inflammatory, like ibuprofen or a prescription medication," says Starkey. "Those medications or injections have an anti-inflammatory effect on the body, but the acupuncture needles can do that naturally."

The influx of new research has helped legitimize alternative therapies like acupuncture, says Starkey. "That’s really brought acupuncture to the forefront of people’s minds and attention, and physicians are a lot more willing to refer their patients to an acupuncturist." 

Acupuncture May Offer Real Relief for Chronic Pain

Some people swear that regular sessions of acupuncture help relieve their back pain and headaches. And now there’s evidence they may be right.

In a study published in the Archives of Internal Medicine, researchers led by Andrew Vickers, an epidemiologist and biostatistician at Memorial Sloan Kettering Cancer Center, report that acupuncture is effective in reducing people’s chronic pain  — more so than standard pain treatment and slightly better than using sham needles, suggesting that the benefits of real acupuncture are due to something more than the placebo effect.

The findings counter those of the last large study on the subject, which found that the needle technique was no better than a fake acupuncture treatment — using random pricking with toothpicks — in reducing people’s pain. But Vickers says his meta-analysis of the data, in which researchers reviewed 29 previous studies involving 17,922 participants, does a few things the previous studies did not. For one, he and his colleagues began by looking at only the most rigorous trials involving acupuncture and pain relief — those that directly compared acupuncture treatment with some type of sham needle therapy in which needles were either inserted only superficially or placed in locations that are not known by acupuncture standards to be key treatment points in the body. The authors of the analysis contacted each of the researchers on the previous studies to discuss with them how they separated the two treatment groups. By limiting their review to the most robust studies published, the authors could assess with more confidence acupuncture’s true effect on participants’ reports of pain before and after treatment.

Next, rather than simply summing up the total effect of acupuncture reported by researchers in previous studies, Vickers’ team asked for their raw data on individual participants’ self-reports of pain. Not all scientists use the same scale for reporting results, which makes it difficult to compare and consider such measurements of pain as a whole. With the raw data, Vickers and his team were able to standardize the participants’ responses and compare them in a more meaningful way.

The result was a clear and “robust” effect of acupuncture in relieving chronic pain in the back, neck and shoulders, as well as pain due to osteoarthritis and headaches, Vickers’ team found. Compared with people undergoing sham needle treatments, those receiving acupuncture reported drops in back and neck pain of 0.23 standard deviations, and of 0.55 standard deviations compared with those not using acupuncture at all. On a pain scale of 0 to 100, that meant that among the participants, who started out with an average baseline pain score of 60, pain ratings fell to 30 on average for those who got acupuncture, 35 for those who received fake acupuncture, and 43 for people who got usual care and no acupuncture.

“The effects of acupuncture are statistically significant and different from those of sham or placebo treatments,” says Vickers. “So we conclude that the effects aren’t due merely to the placebo effect.”Acupuncture is an ancient Chinese remedy for a curing a host of chronic ills, from headaches to back pain and menstrual cramps. The practice, like all medical traditions from the East, is built on the concept of maintaining the balance of various body elements — including blood and nutrients along with less measurable ones like the energy force known as chi. Inserting needles at designated point on the body is supposed to intercept or unblock the flow of such elements, and lies at the heart of the centuries-old therapy of acupuncture.

However, these theories are completely foreign, even weird, to Western medicine, which has a harder time accepting unquantifiable entities such as chi. That’s why Western researchers have struggled not only to document objective evidence of acupuncture’s effectiveness, but also to provide some hints about how it may work.

Some doctors say the needles may release endorphins, the pleasure-inducing, painkilling chemicals that saturate the brain and numb pain signals. But such theories can’t fully explain why acupuncture patients say their chronic pain episodes become less frequent and less intense over time, with regular, long-term sessions. Some say the benefits of acupuncture are purely in the mind, a psychological placebo effect. But either way, for many pain patients, acupuncture does provide palpable relief.

Asks Dr. Andrew Avins in a commentary accompanying the study, if the treatment works, does it really matter whether the effect is physiological or psychological? “At least in the case of acupuncture, Vickers et al have provided some robust evidence that acupuncture seems to provide modest benefits over usual care for patients with diverse sources of chronic pain,” he writes. “Perhaps a more productive strategy at this point would be to provide whatever benefits we can for our patients, while we continue to explore more carefully all mechanisms of healing.

”In other words, if it works and doesn’t seem to lead to any harms, getting stuck with needles may not be such a weird idea after all.

Acupuncture May Change the Way the Brain Perceives Pain

The idea of pricking your body with needles in order to relieve pain seems nothing if not counterintuitive, but thousands of acupuncture patients swear the treatments are effective in addressing pain of all kinds. 

But how does it work? How much of the relief is due to the placebo effect — the mere perception that the needles are actually dulling pain — as opposed to a real biological change in the way nerves signal the brain to pain? 

A new study lends support to the notion that acupuncture may actually modulate the brain’s perception of pain. In a study that used functional magnetic resonance imaging (fMRI) to track brain activity both before and during acupuncture, researchers led by Dr. Nina Theysohn at the University Hospital in Essen, Germany, and colleagues at University of Duisburg-Essen documented a specific pattern of brain activation during acupuncture that may represent an accessible pathway for addressing pain. 

In the small trial, which involved 18 volunteers, each volunteer was placed in the fMRI scanner and then given a small electrical stimulus in the left ankle to generate pain. Acupuncture needles were then inserted at three places on the right side corresponding to regions known to modulate the ankle pain, and the fMRI was repeated. Comparing the brain scans before and after acupuncture, the scientists found that areas of the brain that were active during the pain stimulus were dampened during acupuncture, suggesting that the needles actually do cause a change in the way that the brain perceives and processes pain. 

“This study helps to clarify the brain’s function in terms of how or where it processes pain and where that processing can be modified by the application of acupuncture intervention,” says Dr. Michael Brant-Zawadzki, an adjunct professor of radiology at Stanford University, commenting on the study. 

What’s most exciting, says Brant-Zawadzki, is that the brain regions identified in the fMRI scans may lead researchers to find a more standardized approach to treating pain that may help more sufferers. “If we could find one part of the brain that modulates the pain response in the vast majority of individuals, we could address pain through acupuncture or drugs or even sham acupuncture,” he says, “and we would have a better approach to the pain conundrum than we currently have.” 

The study authors were not able to match up the brain regions activated by acupuncture with similar scans of those treated with medications or other pain relieving treatments, but such studies could help to narrow down the most potent pathways to alleviating pain of all kinds. Theysohn cautions that the findings are too preliminary to draw any conclusions about how acupuncture actually works, acknowledging that “we don’t exactly know what is going on in there, but we can say that brain activity in all regions of interest was lessened under acupuncture.” It might be further proof that acupuncture’s benefits may, after all, be all in your head.