Great Disease Enemy, Kak'ke (Beriberi) and the Imperial Japanese Army, The

Military Medicine,  Apr 2006  by Hawk, Alan

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Although Japanese military officials had discovered that an improved diet could prevent beriberi by the late 19th century, their soldiers in the army suffered from beriberi during the Russo-Japanese War and World War II. A change in diet at the end of the Russo-Japanese War solved the problem and the army applied the lesson learned, along with postwar scientific discoveries about nutrition, toward the diet used during World War II. However, beriberi again plagued Japanese soldiers, this time due to poor logistics and unpalatable dietary supplements.

Introduction

Soldiers of the Imperial Japanese Army suffered much from beriberi (or Kak'ke in Japanese) during the first half of the 20th century. Beriberi is the result of a prolonged thiamin deficiency with symptoms including fatigue, poor reflexes, irritability, memory loss, and sleep disturbances. More severe cases include neuropathy of the legs and/or edema accompanied by high-output congestive heart failure.1 During the Russo-Japanese War (1904-1905), approximately 80,000 soldiers with beriberi were sent home, 10% of whom died. During the battle of Guadalcanal in 1942, U.S. Army intelligence concluded that of the approximately 37,000 Japanese soldiers deployed, more than one-half of those who had been on the island over 3 months had beriberi.2 These findings are surprising because beriberi is an easily preventable disease by means known to the Japanese military. The research leading to this understanding of the disease was one of the landmarks of 19th century Japanese medical research.

Japan's reliance on rice as a staple made beriberi inevitable. Rice was considered the heart of Japanese civilization. Polished white rice was more desirable than rice still in husks, and was even considered a status symbol; it also had the advantage of having a longer shelf life. The Japanese were proud of their diet. In 1906, Col Valery Havard, an American medical officer who observed the Russo-Japanese War, reported that the Japanese attributed:

... their physical and mental strength to their plain, frugal diet, the free use of water (internally and externally), gymnastics and temperate habits. A laborer will work a whole day on a dinner of tomatoes, cucumber and salad, but I hope it is seldom that he is obliged to do without his favorite bean soup or boiled rice. Tea is taken without milk and sugar.

However, he added, "The result of this regime is a race of small stature (compared with Chinese and Koreans), prone to beriberi, but hardy and sturdy, and with wonderful mental power of expansion and assimilation."3

The discovery that beriberi was caused by a nutritional deficiency was one of the triumphs of 19th-century Japanese medicine. Baron Kanehiro Takaki (Fig. 1), who was taught medicine by the English physician William Willis,4 entered the navy as a medical officer in 1872 and quickly realized that many sailors were afflicted with beriberi. It was a disease about which he had some knowledge. He remembered that when he was younger, his father, a Daimio sent to protect the Imperial Palace in Kyoto, told him about beriberi, which caused the death of many palace guards. According to Takaki, They attributed the cause to food, and called the provision box the beriberi box."5 By the time he had left for England to continue his medical education, he had seen several hundred cases at the Naval Hospital, many of which ended in death. Upon his return in 1880, little had changed. As he studied the cases, he was unable to discern a pattern. Although beriberi was common in the late spring and summer months, it was not limited to warm weather. Its occurrence varied in naval bases as well as on different vessels. Although sailors might share the same quarters on a given ship, some would develop beriberi and others would not. Takaki observed that European sailors seldom had beriberi, despite being in the same waters, exposed to the same climate, living in similar ships, and engaging in similar tasks.6 In 1883, he inspected living conditions onboard naval vessels and in barracks and observed that although working hours, clothing, and cleanliness of quarters were similar throughout the navy, there was considerable variation in the diet.

Based on scientific estimates that a person's diet should include 350 g of carbon and 20 g of nitrogen, Takaki concluded that the navy's diet was insufficient in nitrogenous substances. Takaki developed a diet with a better ration of nitrogen and carbon that was tested on the vessel Taukuba in 1884 as it sailed to New Zealand, South America, and Hawaii. This voyage recreated an 1883 cruise of the training ship Ryujo that resulted in 169 cases of beriberi, 25 of which were fatal, among the 276-man crew. In contrast, the Taukuba arrived in Honolulu with only 14 cases. Upon investigation, Takaki discovered that all 14 had refused to eat the nitrogen-rich portions of the diet such as condensed milk and meat.7 Based on these findings, his diet plan was adopted for the fleet and the ratio of beriberi per 1,000 of the force dropped from 1.244 in 1884 to 0.004 in 1886.8 The diet was based on a faulty premise since, by the 1930s, scientists had discovered that beriberi was the result of a thiamin deficiency. In his search for a balanced nitrogen-carbon diet, Takaki had stumbled on a combination of foods that provided the thiamin that polished white rice lacks.1,9