Secular trends in growth of African Pygmies and Bantu.

OBJECTIVE The aim of this study was to investigate whether a secular trend in growth occurred during the last century in Pygmies from Cameroon (West Pygmies) and in Bantu rural farmers, the latter being studied to serve as controls. DESIGN The evolution in height of West Pygmies and Bantu farmers from 1911 to 2006 was evaluated using data from the literature as well as data gathered by our research team during an expedition to Cameroon in 2006. RESULTS During the last century, no secular trend in west Pygmies is apparent, as height changed from 151 cm to 155 cm in males and from 143 cm to 146 cm in females. A small though significant (p=0.026), increment (about 2 cm) was observed only in female subjects during the last ten years. By contrast, Bantu heights show a significant change from 1943 to 2006 for both males (from 159 cm to 172 cm; p=0.025) and females (from 148 cm to 160 cm; p=0.029). CONCLUSIONS Over the last century, the Bantu population exhibited a significant secular trend for height, whereas West Pygmies did not increase their linear growth. The lack of secular trend in Pygmies possibly suggests that their stature reflects adaptation to the forest lifestyle. We may hypothesize that not only environmental but epigenetic factors have also contributed to their growth potential.