Chronotherapy in Traditional Chinese Medicine

American Journal of Chinese Medicine, Summer-Fall, 2000 by Noah Samuels

Abstract: The circadian rhythm of illness has been emphasized for thousands of years in Traditional Chinese Medicine (TCM), using this knowledge to schedule therapies such as acupuncture during appropriate hours of the day. This paper reviews the time periods (two hour segments) that apply to each organ system according to TCM (lungs, large intestine, stomach, heart, kidneys and liver), and elaborates on how recent medical research has found similar relevant biorhythms in these very same organ systems.

The biorhythm of illness is not a new subject, with reports of the early morning symptoms of ischemic heart disease appearing in the literature as early as 1772 (Heberden, 1772). Recent research has emphasized not only the understanding of the diurnal variation of disease, but also the importance of timing treatment protocols accordingly, taking into account the circadian rhythms of the absorption, distribution, elimination and effects of medications on the gastrointestinal tract, liver, kidneys and other organs (Smoleknsy et al., 1995). Thousands of years ago, in ancient China, chronotherapy played an important and well-defined role in the diagnosis and treatment of illness.

Traditional Chinese Medicine (TCM) works on the premise that the human body has various forms of energy, or "Qi" (pronounced "chee"), which flow through a series of well-defined tracts on the limbs, trunk and face. These routes are called "meridians", which in turn correspond to internal organs responsible for the vital functions of the body. Any imbalance in Qi--whether it be excess, deficiency or improper flow--will lead to disease. Treatment entails proper diet, physical activity (such as Tai Qi, or "moving the Qi"), herbal therapy and the superficial insertion of needles in selected points on the imbalanced meridian. This last form of treatment is known as "acupuncture", whose purpose is to re-establish the normal circulation of Qi within the meridian, and, subsequently, the affected organ.

Chronotherapy in TCM encompasses the recognition of the diurnal variation in the flow of Qi throughout the internal organs and the treatment of imbalance, by acupuncture, at specific times. One of the classic and most important works written on TCM is "The Yellow Emperor's Classic of Medicine", thought to have been written by the emperor Huang Di, who reigned during the middle of the third millenium BCE (Ni, 1995). In this discourse, he explains that Qi takes its course through the 12 organ meridians over a period of 24 hours, spending two hours at maximal levels in each organ (referred to as the "twelve branches" theory) (Mao, 1993). In general, when treating a patient in accordance with this biorhythm, the best time to treat an excess of energy is at or shortly before the time of greatest meridian activity, while the best time to treat depleted energy is following the peak (Manaka and Urquhart, 1972). The peak times of Qi for each organ can be seen in Table 1. In TCM, the functions of the organs are not always the same as they are understood today. Still, when observing how ancient Chinese medicine understood chronotherapy, one cannot help but be impressed by the similarities with the discoveries of modern research. Presented are a few examples of such similarities.

Table 1. Two-Hour Peak Periods of the Twelve Organs in
Traditional Chinese Medicine (see text)

Time Period   Time Branch   Organ

03:00-05:00   Yin           Lungs
05:00-07:00   Mao           Large Intestine
07:00-09:00   Chen          Stomach
09:00-11:00   Si            Spleen
11:00-13:00   Wu            Heart
13:00-15:00   Wei           Small Intestine
15:00-17:00   Shen          Bladder
17:00-19:00   You           Kidneys
19:00-21:00   Xu            Pericardium
21:00-23:00   Hai           TripleWarmer
23:00-01:00   Zi            Gallbladder
01:00-03:00   Chou          Liver

1. Lungs (03:00-05:00)

In TCM, the lungs are responsible for breathing, as well as for controlling the protective Qi of the body (called the "Wei Qi"). This protective Qi prevents external pathogenic factors (such as viruses) from invading the body. Imbalance in the lungs will lead to respiratory disease, as well as recurrent infection, especially of the upper respiratory tract. In Western medicine, nocturnal worsening of asthma is a well-known and well-documented phenomenon, with peak flow values at their lowest at 04:00. Diurnal changes in the plasma levels of cortisol, epinephrine, cyclic AMP and histamine are thought to be the cause of this exacerbation (Barnes et al., 1980). As such, treatment with long-acting beta 2 agonists, theophylline, anticholinergics, corticosteroids and leukotriene-active drugs given at certain hours during the day have been found to decrease the incidence and severity of nocturnal asthma attacks (Martin and Banks-Shlegel, 1998). In TCM, treatment is aimed at this time slot, when symptoms are most severe.

2. Large Intestine (05:00-07:00)

In TCM, the large intestine is responsible for digestion and excretion. However, it also has a role in the immune system of the upper respiratory tracts as the counterpart organ of the lungs (all of the internal organs are paired--the lungs with the large intestine, the stomach with the spleen, the heart with the small intestine, the bladder with the kidneys, the liver with the gallbladder, and the pericardium with an organ-like entity called the "triple warmer"). Often an acute viral illness can be felt in the pulse at the position of the large intestine (pulse diagnosis is one of the fundamentals of TCM). More recent research has shown that sufferers of viral and allergic rhinitis ("hay fever") have the most severe symptoms at this hour (Smolensky et al., 1995; Nicholson and Bogie, 1973), with "blocked nose" at 5:00 a.m. and "runny nose" at 6:45 a.m (Smolensky et al., 1995). Studies of HI-receptor antagonists showed maximal benefit when administered in the early evening (resulting in peak levels in the early morning) (Reinberg et al., 1985). According to TCM, treatment of this meridian is very effective for acute viral and allergic symptoms.