Reevaluating the health and nutritional status of maize-dependent populations: Evidence for the impact of pellagra on human skeletons from South Africa

Pellagra, a niacin/ tryptophan deficiency disease, is prevalent in populations that have high maize/ low protein diets. Historically it has been essentially a disease of undernutrition and social inequality. We offer a unique analysis of both macro- and microstructural skeletal indicators from 31 individuals known to have died from pellagra ( n = 14) and non- specific general malnutrition ( n = 17). These cases are part of the Raymond Dart Skeletal Collection, housed at the University of Witwatersrand Medical School, Johannesburg, South Africa. This sample was drawn from a mid- to- late 20th century Black South African population. These individuals were found to exhibit a high incidence of alveolar bone loss, dental caries, enamel hypoplasias, periostitic lesions, osteomyelitis, cribra orbitalia, and cranial pitting. The frequency of specific pathological indicators separated the pellagrins from those with non- specific general malnutrition; however, the indicators were not pellagra- specific. We strongly argue that pellagra does affect bone in a noticeable way at both the macro-and micro- level, and therefore as a diet- related disease cannot be excluded as a possible cause for lesions seen in maize- dependent populations. We have also reported on the histological findings for rib samples taken from a subset of pellagra ( n = 10) and general malnutrition ( n = 14) cases. The critical difference between pellagrins and non- specific malnutrition cases was a decreased cortical area for pellagrins. Given its implications for interpreting the paleonutrition and paleopathology of prehistoric and historical transitions to maize intensive diets we present a checklist of macro- and micro- level indicators for investigating a signature pattern for the skeletal biology of pellagra. The overall synthesis of our findings provides new insights into skeletal- based interpretations of nutrition and micronutrient- related health problems for populations undergoing dietary transitions both past and present.