What we do not understand about acupuncture

Like on needles

Is it possible to reach the internal organs of a person to repair something in them without pills and operations? Hundreds of doctors around the world believe that it is possible: it is enough to stick a steel needle at a certain point on the body surface, leave for 20-50 minutes – and after 5-10 sessions wait for improvement. Hundreds of scientists with them disagree – because mechanisms through which acupuncture acts are still unknown. We tell how this practice could work and why no one knows whether it really works.

Acupuncture is considered part of alternative medicine – and this is to determine the public health service of Great Britain, "Not Mainstream". However, the number of adult people who enjoy it grow. It is resorted to a variety of diseases: pain, inflammation, insomnia, depression and even gonorrhea. The number of institutions that provide this kind of service are growing. In Russia, these are official clinic certified by the Ministry of Health. Take acupuncture, for example, in the Sechenovsky Medical University.

However, in the scientific community about the acupuncture there is still no consent. While some authors are convinced of its effectiveness, others believe that she "is experiencing their autumn" or even refer to her "theatrical placebo." And the fact that 88 percent of WHO participating countries approved the use of acupuncture, they do not convince them at all.

Time shows

Acupuncture is the central practice of traditional Chinese medicine (TCM). Therefore, in China itself, additional confirmation of the fact that it really works, not needed. Chinese historians argue that people resorted to her back in the 10th century BC – and therefore, we can assume that it has already sustained the time check. But as far as it is ancient in fact, it is not clear: the unequivocal mention of acupuncture belongs only to the X century of our era. In addition, it, apparently, until the 20th century, played only a supporting role in other treatments, such as massage and grass.

At the beginning of the 20th century, European medicine came to China, and the emperor completely banned acupuncture, and with it the rest of traditional practices. They were returned to the use of Mao Zedong, when during the cultural revolution of the 1960s, he needed an alternative for Medicine "Ploying West". Then, traditional Chinese medicine with acupuncture was created at the chapter. And now it is already difficult to say to what extent the modern acupuncture continues an ancient Chinese tradition.

Then alternative medicine moved to the West, where it quickly became popular. There, acupuncture overtook new modifications: instead of needles, the electrodes or laser began to use – in order to stimulate active points in a new way. And at the same time, neurophysiologists and evidence-based medicine were interested in her – and the conclusions to which they came, turned out to be very ambiguous.

For example, Western scientists have found that acupuncture really helps relieve some types of pain (toothache, headache, and osteoporosis), as well as cope with nausea and insomnia. In other cases — with alcohol addiction, rehabilitation after a stroke, nausea during chemotherapy — it did not help alleviate the condition of patients or worked at the placebo level. Why it helped in some cases, but did not work in others, they failed to understand. No one has yet created a single theory that would explain why acupuncture can be effective or useless – there are only a bunch of separate hypotheses.

Exactly

To imagine how this or that injection affects the body, you need to understand what is the peculiarity of the place into which the therapist sticks the needle. Traditional acupuncture describes about 2000 points on the human body, and the doctor does not choose his targets randomly.

This practice is based on the classical ideas of Chinese philosophy, including the so-called "theory of system correspondences." She argues that everything in the world is a system in which parts of one phenomenon correspond to parts of another. For example, each sensory modality (like seeing or tasting) corresponds to a particular color and material. Thus, a violation in any part of the system leads to a violation in other parts corresponding to it. And at the level of the human body there are such correspondences – between individual organs and areas on the surface of the body.

Disease in this logic is an incorrect distribution of life force or Qi energy (not to be confused with energy in the modern sense), which moves along special channels (meridians). Therefore, in order to increase the flow of Qi to the desired organ, it is enough to stimulate the area on the skin with a needle. For example, one of the points on the foot is associated with insomnia, but it is important not to miss – very close, a little closer to the heel, there is another point that is considered responsible for the work of the gonads.

How the acu-point or meridian is arranged from a biological point of view is still unclear. Some scientists, for example, found that the concentration of iron, copper, calcium and zinc is increased in the tissue around such points, and these special zones have the shape of an ellipse. Others have noticed that small blood vessels are concentrated in the region of some acupoints. Still others found that at points along the meridians, the electrical resistance of the tissue is reduced, and the higher it is, the more severe the disease corresponding to the meridian (this was tested using the example of bronchial asthma). Fourth – that the zones of active points are enriched with nerve endings. But every time there are skeptics who say that all this data is unreliable, obtained in bad faith or does not withstand subsequent checks.

CT scan results (left and center) and 3D model (right) show branching vessels at acupoints (a, c) and their absence in other areas of the skin (b, d)

Dongming Zhang et al./ Analytical and Bioanalytical Chemistry, 2011

To the brain and back

In any case, points alone are not enough to explain how acupuncture could work. It is also necessary to find an intermediary between a point on the surface of the body and an organ in its depths. The most likely candidate for this role – it is not for nothing that in Russia acupuncture is referred to as reflexology – is a reflex arc, that is, a chain of neurons.

Any reflex arc includes five elements. The first element is the receptor, in the case of acupuncture, various tactile or pain receptors on the skin. The second is a sensitive neuron with its processes that carry information from the receptor to the spinal cord or brain. The third is the central link, one or more neurons in the spinal cord or brain, which "pick up" the body's response to an incoming stimulus. The fourth is a motor neuron with processes that transmit a signal to the last, fifth, working organ. This may be a muscle that controls the movements of body parts or an organ (for example, contractions of the heart or constriction of blood vessels), or a group of other cells that, in response to a signal, can release substances into the blood, take them from the blood, or somehow change your life activity.

Scheme of the classical reflex: from the receptor through the spinal cord or brain to the motor neuron and muscle

Eric Kandel et al. / Principles of neural science, 2012

But more often, scientists suggest that at the end of the reflex arcs through which acupuncture can work, there is a cell that releases some kind of bioactive substances. These can be cells in the wall of the vessel that release nitric oxide (II) into the blood – and that, in turn, expands the lumen of the vessel and thereby increases blood flow to the desired organ. Or it could be cells in the central nervous system. For example, spinal cord neurons that secrete enkephalins, endogenous opioids that suppress pain.

There are also suspicions that acu-reflexes do not stop at the level of the spinal cord, but pass further, to the brain. At least, it turned out that pressing the acupoint changes the activity of certain areas of the brain (according to functional MRI), as well as the range of proteins that hypothalamic cells produce. Some neurons, for example, have additional receptors for serotonin, which could explain how acupuncture affects depressive symptoms. Other cells, probably under the influence of acu-reflexes, begin to secrete met-enkephalins and endorphins – and thus could suppress pain. And since these substances have not only analgesic, but also immunomodulatory effects, this would explain how acupuncture is involved in the normalization of immunity, a result obtained in some studies.

But it may also be that acupuncture does not cause full-fledged reflexes, but covers already running ones.This is possible if two reflexes have a common central part of the reflex arc: the neuron carrying tactile information and the neuron carrying pain information terminate on the same central neuron in the spinal cord. Then the "tactile" neuron can extinguish the signal from the "pain" neuron, and the signal does not reach the brain. The same theory, by the way, explains why certain types of massage sometimes help with pain.

It turns out that the effect of acupuncture, which is observed by some researchers, can be explained by a variety of mechanisms. But for now, all these conjectures remain hypotheses: in order to confirm them, it is necessary to consistently show in one experiment that after stimulation of the acupoint, all elements of the reflex arc really begin to work and that they are responsible for the observed effect.

This has been done so far in only one experiment, quite recently. The researchers completely traced the acu-reflex arc from a point on a mouse's hind foot to inflammatory proteins in the blood. It turned out that stimulation of the point leads to the activation of certain zones in the spinal cord. They, in turn, send a signal to the structures of the medulla oblongata (the lowest part of the brain), and those activate the adrenal medulla, which release dopamine, adrenaline and norepinephrine, which have anti-inflammatory effects, into the blood.

Thus, it is indeed possible to find a biological mechanism for acupuncture, and researchers will probably not limit themselves to the reflex arc alone. Next, scientists will have to find out whether the human body really has secret passages to all organs through the skin and a universal system of self-healing – or whether the creators of acupuncture built a large (but not really working) system based on point successes.

Scheme of the reflex arc connecting the acupoint with the adrenal glands

Qiufu Ma et al. / Nature, 2021

Where is the obstacle

Now acupuncture does not look like a universal remedy – at least, it regularly fails clinical trials. One can, of course, assume that the skeptics are right and that all the results in favor of acupuncture are either falsified or misinterpreted. But this is not necessary: ​​there are a number of purely biological considerations that may explain why acupuncture, while effective for some pathological conditions, is completely unsuitable for the treatment of others.

So, it may turn out that not for all the organs that we would like to cure, there is a suitable reflex arc. That is, for example, you can get to the heart with the help of the Ashner reflex, but, say, no chains from the surface of the skin lead to the liver. If so, then the error lies precisely in the fact that the adherents of acupuncture try to present it as a universal method, although it is not.

However, even if acupuncture is really a universal method, you can imagine other reasons why it may not work. The fact is that the reflexes in humans exist in themselves, but inside a very rigid hierarchical system. There are more "senior" reflexes – those in which switching occurs in the brain – suppress "younger", which operate at the level of the spinal cord or the "low floors" of the head. For example, it is possible to force the will (signal from the bark of large hemispheres) to suppress the desire to take heather from the iron (which is responsible for the spinal reflex). The same can occur with the acupuncture: if it launches the reflex, for example, at the level of the spinal cord, then the hierarchical systems that stand above are involved in the pathological process, they may not give Aku-reflex to show themselves.

It follows from this that the acupuncture can work differently for people with a different cultural context. For a resident of China, acupuncture is integrated into the way of life of the people, in his way of thinking, philosophy, and is associated with other traditional practices. All this together, if you use the terminology of the physiologist Ukhtomsky, creates some common dominant in the nervous system and the psyche. This dominant acts as the organizer of all the "older" reflexes, which is managed by the body. In this case, for the Chinese, the acupuncture will work better than for people of alien culture. And the failures on clinical trials were caused only by the fact that the groups of the subjects were heterogeneous – not by the state of health, but according to the cultural context, which modern medicine is not inclined to take into account.

The cultural context affects something and relate to the acupuncture of the researchers themselves. Most skeptical reviews that accuse adherents of this practice in the falsification of data are written by Western scientists. On the contrary, those who consider the effectiveness of acupuncture proven and try to trace its mechanisms (such as the authors of the article on the reflex arc from the skin in adrenal glands), usually from China, Japan or Korea.

Therefore, the answer to the question whether the acupuncture works, it still depends on who to ask it. In the meantime, researchers and doctors continue to argue, regulators are trying to keep neutrality. In 1997, the US National Health Institute supported acupuncture, adopting a declaration confirming that this technique showed its effectiveness in the treatment of a number of syndromes. In 2003, a similar document accepted and WHO.

Acupuncture is not the first and certainly not the last practice that evidence-free medicine subjected to severe checks. And the results are very different: some techniques that yesterday seemed to the remnant of the past, suddenly turn out to be effective – so, for example, bioactive substances are found in Snowball herbs.On the contrary, methods that at one time were considered “scientific” are subsequently recognized as barbaric – as was the case with lobotomy, which was widely used in the middle of the last century to “fight” various mental illnesses (for more details, see our material “Nothing better came to mind”) and bloodletting (and about it, read the material “Blood that was shed for good reason”).

What awaits acupuncture is still impossible to predict. But it is already clear that our ideas about it will have to change more than once. So, for example, at the end of the 20th century, in different parts of the world, archaeologists found mummified bodies of people with unusual tattoos – they did not look like skin decoration at all. On one of them – perhaps the most famous, Ötzi – nine such tattoos coincided with traditional acupoints with an accuracy of 6 millimeters. Ötzi lived about 5200 years ago in the territory of modern South Tyrol (read more about him in the material “From the abyss in the ice”). This means that acupuncture may turn out to be not only more ancient than it is commonly thought, but also a much more Western tradition.