History of salt supplies in West Africa and blood pressures today.

Excess salt consumption has been implicated in the rising prevalence of essential hypertension in West Africa. It has been suggested that low supplies of salt in West African history were responsible for a genetic mutation that predisposes Blacks to high blood pressure. However, historical evidence concerning salt supplies in West Africa suggests that availability was not uniform. For instance, in Senegal and Gambia salt production has been extensive since ancient times, whereas in ancient Nigeria the population had to depend on local vegetables salts or meagre imports of the mineral. Reports that blood-pressures in Senegalese and Gambians are lower than those in Nigerians may be a reflection of historical differences in salt supply. The difference in blood pressure between members of a racial group also casts serious doubt on the concept of racial homogeneity often accepted in the medical sciences, and the relation between blood-pressure and salt availability in West Africa reveals that insights can be obtained from a study of history.