Adolphe Vorderman's 1897 study on beriberi: an example of scrupulous efforts to avoid bias.

This paper highlights Adolphe Vorderman’s investigations of the causes of beriberi using epidemiological observations among prison inmates in the Dutch East Indies (today Indonesia) in the 1890s. His investigations are featured in the James Lind Library because of Vorderman’s scrupulous efforts to avoid bias. He built a number of methodological safeguards into his investigations, both to avoid being deluded by others, and to reduce the likelihood that he would, when collecting and analysing the data, delude himself by potential prejudices about the hypothesis that he was investigating. The story of the discovery of the nutritional cause of beriberi (a lack of vitamin B1) is often recounted as that of a few heroic studies. On the side of ‘basic science’, the highlights are the experiments done by Christian Eijkman in the 1890s in Batavia, Dutch East Indies (now Jakarta, Indonesia), who found that chickens that had developed a beriberi-like illness when fed polished rice, did not do so when they were fed unpolished rice. Later, Frederick Gowland Hopkins, Eijkman’s co-Nobel prize winner, did biochemical experiments in Cambridge, UK, and coined the idea that particular food substances, later called ‘vitamins’, were necessary for human growth and development. As far as human experimentation is concerned, two reports in particular have received attention. In 1906, Baron Takaki published an account in The Lancet of an investigation done two decades earlier, which had been prompted by a severe epidemic of beriberi among Japanese sailors during a long sea voyage. Takaki arranged for a similar ship to follow the same long-distance route but with a much more varied diet for the sailors: and many fewer cases of beriberi were observed among sailors during the second voyage. The other experiment was organized by William Fletcher in 1905 and was reported in The Lancet in 1907. It involved assigning inmates of a mental asylum in Kuala Lumpur, Malaya, alternately to either polished or unpolished rice, and showed that unpolished rice offered protection against beriberi. As is often the case, the development of insights into the causes and prevention of beriberi was a much more tortuous process. Among others, Eijkman was initially not convinced that a nutritional deficiency was the cause of the disease – he was more inclined to think that there was a poison in polished rice. Eijkman’s successor in Batavia, Gerrit Grijns, carried out several more experiments and proposed that the disease was caused by ‘partial hunger’, that is, a lack of particular food substances, and this corresponded to the theories of Frederick Gowland Hopkins. Several more people contributed shrewd observations that gradually reinforced the case for believing that a nutritional deficiency caused the disease. Vitamin B1 was only isolated and purified much later. The ups and downs of different competing theories, infectious, poisons and, nutritional deficiencies were described in Kenneth Carpenter’s monograph in 2000. Adolphe Vorderman (1844–1902), a Dutch government doctor who worked in the Dutch East Indies, was one of the people who made careful observations on groups of humans receiving differing diets. His contribution was exceptional because of the elaborate precautions that he took against potential biases in his investigations, which went a long way beyond what one DECLARATIONS