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Japan: Will the sun set on Kampo?

The practice of traditional medicine in Japan includes many modern techniques but faces numerous challenges — including political pressure from China.

Japan's traditional herbal medicine, called Kampo, has become thoroughly integrated into the country's healthcare system. Of the thousands of Kampo formulae available, 236 are officially registered by the Japanese ministry of health and produced in pill or powder form. More than 80% of medical doctors in Japan currently prescribe Kampo, and two-thirds of the officially registered formulations are covered by national health insurance.

But Kampo — imported from China 1,500 years ago — is under pressure. Despite growing support among the Japanese public, Kampo is eclipsed by Western medicine, which accounts for 98% of total pharmaceutical production in Japan. Kampo also faces fierce competition from the growing popularity of traditional Chinese medicine (TCM).

Part of Kampo's problem is institutional: unlike China and South Korea, where governments promote traditional medicine, Japan has neither government departments nor public institutes dedicated to Kampo. The Japanese government spends about one-tenth as much on traditional medicine research as South Korea, which is only a fraction of the size of China's investment. And the difficulty of accumulating scientific evidence in support of traditional medicines makes the government wary of strengthening its support.

History of Kampo

In the sixth century, TCM spread to Japan and started to develop independently. Kampo medicine bloomed in the eighteenth century when Japan closed itself off from contact with most foreign countries.

Credit: A. MACDONALD

After Japan reopened its borders in the late nineteenth century, the government embarked on a strategy of Westernization, and Kampo was all but replaced by modern medicine. Since then, Kampo has survived on the sidelines of society. In 1976, facing strong political pressure from Taro Takemi — then president of the Japanese Medical Association and a Kampo advocate — the health ministry decided to include Kampo in the national health insurance. But this policy did not require clinical trials to prove the efficacy of Kampo treatments. Indeed, until recently, little importance was placed on the development of Kampo; only a handful of places, including Toyama Medical and Pharmaceutical University (now known as the University of Toyama) and Kitasato University Oriental Medicine Research Center in Tokyo, continued to research it.

Kampo medicine is now enjoying renewed public support. In 2009, a government task force suggested removing Kampo from the national insurance coverage in an effort to cap mounting medical expenses. In only three weeks, the Japan Society for Oriental Medicine in Tokyo collected nearly one million signatures from people opposed to the plan, which was abandoned.

Unique features

Kampo medicine shares many similarities with TCM: they both support the concept of a gradual improvement in the body's condition using natural agents, and diagnosis is made using a pattern of symptoms. But over centuries of independent development, the two systems have diverged in character and practice.

Japan imports 80% of Kampo ingredients from China, although some herbs are grown locally. As with grapes cultivated for wine, local environmental conditions can influence the constituents of a medicinal plant. This means that any given traditional medicine, if it contains herbs grown in different places (even if they are the same species), can have variable properties. Consequently, explains Masatomo Sakurai, a researcher in traditional medicine at Kitasato University, the potency of some Kampo medicines such as kakkonto, a treatment for the common cold, can be one-tenth that of the TCM equivalent — in this case gegentang.

Cultural and political differences also separate Kampo from other Asian medicines. In China, TCM practitioners prepare their own mixtures tailored to each patient (although principal ingredients may be standardized), and can choose whether to train in modern medicine or TCM. In Japan, by contrast, Kampo formulae are manufactured according to rules issued by the health ministry in 1987 to ensure consistent preparations. Kampo doctors must also hold a licence to practise modern medicine. “These features give Kampo an advantage when integrating with Western medicine,” says Ikuo Saiki, director of the Institute of Natural Medicine at the University of Toyama. “Products of standard quality are essential to produce persuasive clinical data.”

Talking politics

Kampo-related issues have recently taken on a political flavour. China has started to regulate exports of raw herbal materials, and has also raised prices. Although cultivation of some plants can be relocated to Japan, certain high-quality herbs, such as Ephedra sinica, can be harvested only in China with the right soil and climate.

“If current Chinese medicine became the standard under international agreement, Kampo medicines could be wiped out.”

At meetings of the World Health Organization and the International Organization for Standardization, the Chinese contingent is promoting TCM as the basis for standards in traditional herbal medicine. “If current Chinese medicine became the standard under international agreement, it would have an impact on our education and qualification systems,” says Katsutoshi Terasawa, director of the Kampo department at the Chiba Central Medical Center in Japan. “Kampo medicines could be wiped out.”

International standards would help avoid confusion over nomenclature and inform a scientific evaluation of traditional medicines. But “if we are to create international standards, we should first set the theme as traditional East Asian medicine, not just Chinese medicine,” says Terasawa. Toshihiko Hanawa, director-general of Kitasato University Oriental Medicine Research Center, adds: “And for Japan, it is imperative that we establish a government support system.” Without such support, there is a risk that TCM will predominate and a vital bridge between East Asian and Western medicine will be lost.

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Fuyuno, I. Japan: Will the sun set on Kampo?. Nature 480, S96 (2011). https://doi.org/10.1038/480S96a

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