Secular trends in stature of late 20th century white South Africans and two European populations.

During the 20th century a general positive secular trend for stature is observed in developed countries around the world while shorter statures, often associated with a lack of a positive secular trend, have mostly been observed in populations with lower SES. The purpose of this study was to compare secular changes in stature between 20th century South Africans of European descent and two European populations. The comparative samples include Dutch males with which there is an assumed genetic relationship, and Swiss males for which the genetic association is less clear. The sample comprised anthropometric stature data of white South Africans (17-62 years), Swiss and Dutch males (18-21 years) obtained from military conscripts with birth cohorts of 5 years from 1946 to 1995. The stature of white South African males did not increase at a significant rate compared to those observed in Swiss and Dutch males. South African and Dutch males were of similar height following World War II, but a considerable trend was observed only in the Dutch group. The Swiss group was initially shorter than the South Africans, but due to a positive secular trend their average stature is on a par with that of South Africans in the most recent cohort. The lack of a significant positive secular trend in the South African group could suggest that factors such as gene flow and poor economic and social development in South Africa resulted in shorter statures in white South African groups than expected.