Traditional Japanese medicine: principles and treatments

Origins of traditional Japanese medicine

During the neolithic period, people believed that disease was caused by demonic spirits invading the body. At that time, the Japanese relied on shamans, who with their amulets, prayers and spell books, would try to exorcise the evil. It wasn’t until the 7^th century BC that early migrants from Korea, Northern China and the Philippines brought with them the first rudiments of medical knowledge.

It was the growth in trade with China, and the influence of Chinese-Korean Buddhism, which really laid the foundations of traditional Japanese medicine from the 6^th century onwards (1).

Initially co-opting all the principles of Chinese medicine, Kampo (literally ‘medicine according to the Han method’) gradually found its own identity at the end of the Tang dynasty around 907. The main differences were a more practical approach, diagnosis based on conjunction of symptoms, and natural remedies made from local plants (2).

Key principles of Kampo

Kampo medicine adopts a holistic approach, in which the person is considered as a whole. With the mind and body believed to form an inseparable entity, in perpetual interaction with the surrounding environment, a state of balance must be constantly maintained.

Unsurprisingly, Japanese medicine is underpinned by some of the foundations of its Chinese counterpart:

• Ki (equivalent to Chinese Qi) corresponds to the life force flowing throughout the body and its fluidity (3);
• In and Yo (the Japanese version of Yin and Yang) represent the duality present in all elements of the universe (4);
• the five element theory is predicated on the belief that each organ, limb or emotion can be described as a combination of metal, wood, water, fire or earth (5).

The importance of touch in Japanese medicine

Palpation of the body occupies a key place in Japanese medicine (6). It enables areas of emptiness (Kyo) and fullness (Jitsu), both signs of energy imbalance, to be identified. Various touch-based practices, based on the art of Chinese medicine, have thus been absorbed into the Japanese tradition.

Acupuncture is a key feature, although practitioners use finer needles which are inserted painlessly via a tube called a Shinkan. Developed largely during the Ming dynasty in China, moxibustion is a form of heat therapy in which moxa, made from dried mugwort (yomogi) is burned near the skin at different points in the body (7). There are various approaches including Okyu (rice grain moxibustion), Kyutoshin (needle moxa), Chinetsukyu (cones) and Bokyu (stick moxa) all of which have their own therapeutic indications.

Adopted by the Japanese over 1000 years ago, traditional amma massage (‘calming with the hands’) aims to encourage the free flow of Ki throughout the body, from the centre out to the extremities (8). It’s based on a series of complex manipulations (kata) consisting of stretching, rocking, pressing and percussive movements, applied to 360 specific points. It was also the inspiration behind shiatsu, later formalised in the early 20^th century (9).

Medical specialities of Japanese medicine

The 30-volume work Ishinpo, by the physician Tanba Yasuyori (912-995), is a comprehensive compilation of Chinese medical knowledge at that time, transcribed into Japanese (10). Even then, medicine was divided into specialities such as internal medicine, dermatology, otolaryngology, surgery, pharmacology, gynaecology, obstetrics and paediatrics. The tome even addresses sexual behaviour and health regimes.

Ophthalmology developed significantly with the arrival of the Buddhist monk Majima Seigan. Bringing together renowned practitioners, he established a school for treating eye problems. The use of eye drops and eye surgery grew (11). His text Majima ryū ganmoku hiden shō was the first work on the subject to be published in Japan.

During the Muromachi period, a series of bloody wars decimated the Japanese population. In order to treat wounds and mutilations on the battlefield, educated fighters became specialist ‘field surgeons’ or kinsō-i, as opposed to the more general ‘boil or furuncle surgeons’ (yōka) who treated civilians. Though ‘invading’ the body’s secrets in this way was considered dirty and impure, they nevertheless made remarkable progress in expanding their knowledge of anatomy and mastering the suturing of wounds.

The Japanese pharmacopoeia

Kampo developed remedies (kampo yaku) by combining elements of nature endowed with medicinal properties (shoh yaku). This could be parts of plants (roots, flowers, fruits, bark, seeds …), minerals or animal substances (skin, bone, shell …), the idea being to treat all symptoms at the same time (instead of addressing each symptom separately) by considering the patient as a whole.

The most popular such shoh yaku include liquorice root (kanzo), a true Asian medicine panacea, ginger (syokkyoh) for its warming properties, and kudzu (kakkon) for regulating the menstrual cycle (12-14). And for improving the flow of Ki, magnolia bark is included in a host of preparations (15).

Mushrooms also feature prominently. Known as the ‘mushroom of immortality’, reishi is a Ki tonic which supports healthy immune function and circulation (16). Since the time of Emperor Chūai, the mycelium of shiitake has been traditionally used to combat physical and mental exhaustion due to its content of alpha-glucan polysaccharides (AHCC) (17).

Modern-day Japan continues to innovate in the field of natural remedies, producing effective dietary supplements including certain ‘postbiotics’, black garlic, etc. (18).