Soon after its discovery (by the mid-eighteenth century), pellagra was also explained as either an outcome of exposure to extreme climates or a product of contagion. In the mid-nineteenth century, Daniel Drake (1850) grouped causes of disease into three classifications. These included telluric or geological, climatic or meteorological, and social or physiological influences. Later in the century, diseases were also found to be caused by agents such as light, food toxins, and pathogens. As each of these agents of disease was recognized, it became a suggested cause of pellagra. Infection, for example, was popular as a causative agent because it seemed plausible that poor sharecroppers, living in fly-infested dwellings, might acquire the supposed “germ” from their surroundings.
Yet the applicability of the germ theory to pellagra could not be demonstrated, and - especially as nutrient deficiencies had been implicated in other diseases, like scurvy - the interest of researchers returned to the diet of the afflicted. But partly because of deliberate attempts to downplay the poverty of workers, and partly because of the reluctance of medical practitioners to agree on a nutritional explanation, it took a long time for the etiology of pellagra to be understood.
In an interesting observation, S. J. Kunitz (1988), in a paper dealing with hookworm infestation and pellagra, remarked that past explanations of these diseases were influenced by investigators’ ideologies and values rather than being derived from analyses of the intrinsic nature of the illnesses. Kunitz further suggested that such biases also conditioned approaches to disease prevention and cure.
Perhaps such influences can be seen in the totally different public-health approaches to pellagra eradication adopted in France in the 1840s and in the United States in the 1940s. In France, Roussel, without any knowledge of the biological cause of pellagra but with a keen observer’s eye for the social environment, urged the French government to drain the salt marshes in southwestern France, where the disease was most prevalent, so that a diversity of food crops could be grown and animals raised. More generally, he was also remarkably successful in getting the French government to change the country’s agricultural system in ways that contributed to the health of the inhabitants of the rural regions (Roussel 1845,1866).
In the United States, Conrad A. Elvehjem of the University of Wisconsin discovered the pellagrapreventing factor, first called nicotinic acid and later named niacin. This “breakthrough” occurred in 1937 as a result of his study of blacktongue, the canine equivalent of pellagra (Elvehjem et al. 1938), and Elvehjem was subsequently influential in promoting the enrichment of bread and cereal grains with niacin in an effort to bring the career of pellagra to a close. The mandatory enrichment program was instituted in 1943, following the recommendation of the Food and Nutrition Board, of which Elvehjem was a member (Wilder and Williams 1944).
Yet, as T. H. Jukes (1989) has pointed out, however successful the bread - and cereal-enrichment program was in preventing endemic pellagra, it was already generally accepted by the 1940s that pellagra could be prevented - and also cured - by what he termed a “good” diet; in this context, a “good” diet was one that included milk and meat. The government, however, chose not to concentrate on changing the living conditions of the disadvantaged, such as sharecroppers and millworkers, but rather adopted a policy of providing them with cheap, niacin-containing staple foods.
Thus, neither the sharecropping system nor pellagra were ended by enlightened public policy. Although the beginning of the end of pellagra in the United States lay in the expedient of food fortification, its ultimate demise can only be found in the economic events of the 1930s and 1940s, which, by bringing greater affluence to the South, both eliminated pellagra as a major health concern and spurred the end of sharecropping (Roe 1974).
World History
