As we now know, beriberi is caused by nutritional deficiency of thiamin (vitamin B1), most commonly associated with reliance on polished white rice. But establishing this, isolating the "vitamin" responsible, and implementing appropriate public health measures was a long and complex process. In Beriberi, White Rice, and Vitamin B Kenneth Carpenter makes of it a fine "medical detective story".
Some kind of connection with diet is not hard to discern — the Chinese writer Han Yu noted around 800 AD that the disease affected rice-eating people in the south but not wheat-eating ones in the north. But a trace vitamin present in differing quantities in a range of foods posed a complex puzzle and there were a plethora of not implausible explanations: a miasma restricted to particular regions, an infectious agent, toxins or an anti-vitamin in rice, and so forth. An added complication was a lack of communication between scientists and doctors from different national traditions.
Regimented groups such as soldiers, sailors, and prisoners were common sufferers; with standardised diets and centralised records, these were also the target of most studies. The Japanese Navy largely eliminated beriberi (kakké) around 1895; naval doctor Kanehiro Takaki thought protein deficiency was the problem, but the measures he implemented worked anyway. The army, however, was convinced beriberi was an infectious disease and suffered over 90,000 cases in the 1905 war against Russia.
The name "beriberi" originated in Southeast Asia, where it had become widespread with the colonial introduction of machine milling of rice. Work on the disease was done by the Dutch in Java, most notably by Christiaan Eijkman, who shared the 1929 Nobel prize for studies using chickens, and by the British in Malaysia and the Americans in the Philippines. Some kind of consensus was reached at the first meetings of the Far Eastern Association of Tropical Medicine in 1910 and 1912.
The isolation of pure thiamin — in the process of which the word "vitamin" was coined — took till 1926, with synthesis achieved in 1938. Chemical analysis explained Eijkman's results and revealed where in the rice grain the thiamin was and how different kinds of milling and cooking affected it; analysis of other foodstuffs helped explain non-rice beriberi cases.
There were disagreements over how much thiamin is needed, whether extra amounts had any beneficial effect, and what public health measures should be implemented. There were various modifications to the production and preparation of rice in Japan and Southeast Asia, while the United States and Britain made addition of thiamin to white bread compulsory during WWII. Australia mandated enrichment of bread and flour in 1991, but in 1998 was still considering the compulsory addition of thiamin to beer, to reduce the incidence in alcoholics of Korsakoff's syndrome.
In a final chapter Carpenter looks back with the benefit of hindsight, considering the social causes of beriberi and the role of luck, competing theories, ethics, and other epistemological factors in the work done on it. Appendix A explains some of the chemistry involved in the isolation and synthesis of thiamin and Appendix B some of the biochemistry of thiamin metabolism.
Carpenter's account is balanced, never putting too much emphasis on individuals or exaggerating the significance of events for effect. Perhaps as a result, it does jump around a little, reflecting the "messiness" of the history. But Beriberi, White Rice, and Vitamin B is never slow or dull: it offers insights into epidemiology, the history of medicine, and public health, all wrapped up in an entertaining narrative.