One of the mechanisms of acupuncture effect is increasing blood circulation
Acupuncture is originated from China 2500 thousand years ago and the theory is based on the meridians and energy (Qi) flow through the body. Recent scientific research on acupuncture provided evidence of the mechanisms of acupuncture. In 1950s Chinese government began to invest in research on acupuncture. The interest in acupuncture is increased not only for medical professionals all over the world, but also for researchers. They would like to know how the needles work. Since 70’s, acupuncture becomes more and more popular in US and European countries. In 1971, a report in the New York Times inspired American doctors to China to study analgesia effect of acupuncture. In 1990s there was a remarkable increase in acupuncture research. The publications of acupuncture research continue to increase. Acupuncture has received an enormous boost in the last few years. In 50 years the achievements of acupuncture research is extraordinary. The National Institute of Health consensus conference in 1997 recognised acupuncture (and by extension Traditional Chinese Medicine) as a legitimate branch of scientific medicine. Acupuncture seems very likely to be accepted and incorporated into Western medicine. Acupuncture becomes popular than ever.
Acupuncture increases local blood flow.
Regulating blood flow both centrally and peripherally are important in contributing mechanism of acupuncture.
Recently a study investigated the changes of local blood flow in response to acupuncture stimulation. In this study eight random controlled trials involved 205 participants were included. In most of the selected studies, acupuncture was performed at points located distal to the elbows and knees such as LI4, ST36, and PC6, whereas one study simultaneously used several acupoints on the extremities. In one study the GB21 acupoint on the posterior region of the shoulder was stimulated with an acupuncture needle. All eight studies selected for the present review observed acupuncture-induced changes in blood flow in the skin, whereas three studies observed changes in blood flow in the muscle. Four reported significant increases in blood flow following acupuncture compared with control, whereas one other study observed reductions in microcirculation immediately after acupuncture needling. The studies that assessed patients with either fibromyalgia or trapezius myalgia found significant increases in blood flow in the skin and muscle. Additionally, the degree and duration of increases in microcirculation varied depending on the condition of the subjects and the manipulation technique.
Another study about effect of acupuncture in peripheral tissue perfusion has been done on two healthy subjects. Acupuncture was performed on two acupoints (LI4 and SI3) which are in the hands three treatments within 1 week. Local blood perfusion on the hands was measured before and after acupuncture treatments. The result has shown that the blood perfusion rates of the hands were noticeably increased immediately after acupuncture at the first treatment in both cases. At the third treatment the increased blood perfusion was seen in one case, not the other one.
Hsiu H et al studied the microcirculatory blood flow response following acupuncture stimulation using beat to beat laser Doppler flowmetry (LDF) which could provides important information on the circulatory regulatory activities. Changes in the arterial pulse transmission or the opening condition of arteriolar opening might change the fluctuation pattern of the microcirculatory blood supply. They measured LDF signals to study the microcirculatory blood flow response at the needled site particularly at Hegu LI4 acupuncture point) after acupuncture stimulation. They selected 29 male healthy volunteers to measure microcirculatory blood flow after acupuncture stimulation. The measurements were at three times: before acupuncture stimulation, immediately after acupuncture stimulation and about 1 hour after acupuncture stimulation. They found that acupuncture not only improves local blood supply and but also regulates microciculatory blood flow by altering microcirculatory blood supply parameters. Their findings could help to identify the mechanism underlying the effects of acupuncture stimulation.
Acupuncture increases blood perfusion around the acupoints.
Researchers are using modern techniques to study the mechanisms of acupuncture to explain the phenomenon from modern science aspect. Li XM et al studied influence of different acupuncture manipulations at Zusanli (ST36) on skin microcirculation blood perfusion in healthy subjects. They measured local blood perfusion at ST 36 acupuncture points after acupuncture stimulation at 1min, 5 min, 10, 15min, 20 min, 25 min and 30 min. They also compared blood perfusion levels of microcirculation around the acupoints among the different manipulation techniques. They found that microcirculation around the selected acupoint was significantly increased from 1-10 min following simple needle insertion, from 5 -30 min after uniform reinforcing-reducing manipulation, from 1-30 min after reinforcing manipulation, and from 1-25 min following reducing manipulation respectively. The reinforcing manipulation was superior to other techniques. From this study we can see acupuncture increases local blood perfusion in normal subjects. The reinforcing manipulation had better effect.
Acupuncture dilates blood vessels
Research has shown that there were more of nerve fibers/trunks, blood vessels, hair follicles, and sweat glands as well as density of the gap junction in the acupuncture points. Recent research has shown that nitric oxide (NO) level is elevated in the acupoints and is associated with an enhanced expression of NO synthase endowed with transient receptor potential vanilloid type-1. This suggests that acupuncture induces NO-mediated vasodilatation, which increases local blood flow and allows for a flush of algesic or sensitizing substances, leading to pain relief.
Microcirculation and water retention
Microcirculation is the blood flow in the small blood vessels which spread out in organ tissues. These blood vessels include arterioles, capillaries and venules. The main functions of the microcirculation are the delivery of oxygen and nutrients to the tissues and the removal of CO2 from the tissues. It also regulates blood flow and tissue perfusion. Microcirculation responds to inflammation which is related to swelling. Capillaries are a sector of the microcirculation where gas and fluid exchange take place. About 7% of the blood in the capillaries is continuously exchanges with the fluid outside of the blood vessels. If there is problem with microcirculation, such as compression of the part of the body, the microcirculation is likely to be disturbed and water retention occurs. Acupuncture stimulates the nerve ending and relaxes blood vessels and skeletal muscles, it improves microcirculation and relieves water retention.
Acupuncture helps lymphatic circulation
The lymphatic system is a part of the circulatory system and it also involves immune function of the body as a part of the immune system. It consists of a network of lymphatic vessels which carries lymph-a clear fluid in the body which formed from tissue fluids known as interstitial fluid from the tissues. It carries large amount of lymphocytes and other white blood cells which play a role in the immune function. Its main function is to help tissue fluid circulation. The lymph capillaries absorb the interstitial fluid from the tissues and lymph vessels conduct the fluids to the blood vessels. As a part of the defence system, it also contains waste products and cellular debris together with bacteria and proteins etc which are toxic to the body.
The lymphatic system is responsible for maintaining the balance of the body fluids. Its network of capillaries and collecting lymphatic vessels work to efficiently drain and transport the fluid, along with proteins and antigens, back to the circulatory system. The lymphatic system is not closed system and the vessel walls are not as strong as blood vessels. If the circulation is blocked for various reasons, e.g. there is tension on the body, the transportation is disturbed and the fluids cannot be drained properly causing water retention. Also the toxins could remain in the body longer than they should be causing toxic to the body.
Acupuncture can help lymphatic circulation, improve water retention and help get rid of toxins of the body.
References
Kim S et al Evid Based Complement Alternat Med (2016) 9874207. doi: 10.1155/2016/9874207. Epub 2016 Jun 14.
Li XM et al Zhen Ci Yan Jiu (2013) 38:297-300
Wang W et al Chin J Integr Med (2007) 13:10-6
Fang JL et al Zhen Ci Yan Jiu (2012) 37:46-52
Yan G et al Evid Based Complement Alternat Med 2013: 2013:429703
Guo L et al Biomed Mater Eng. 2013 23(0):S1115-S1121
Hsiu H et al Microvasc Res (2013) Jun 24
An Y et al Med Devices (Aucl) (2014) 7:17-21
Ma SX Chin JIntegr Med (2017) 23:812-815
