Blood pressure and dietary salt in human populations

The literature on blood pressure level and salt intake in a cross‐section of the world's populations is reviewed. Regression and correlation analysis suggest a direct linear relationship between these variables. In three pairs of genetically related primitive populations, higher blood pressures are observed in the more acculturated group in each set, with salt intake being higher in these as well. In more culturally homogeneous groups, particularly Japanese and Taiwanese, salt intake appears to be the major environmental factor affecting blood pressure. African populations are discussed in relation to type of economy, blood pressures being higher in agricultural groups than in hunters or herders. There are indications that salt intake is higher for agricultural groups. It is suggested that populations vary in their sensitivity to sodium as a result of past selection for superior salt retaining capacity in tropical peoples. It is further suggested that high blood pressures of American and West Indian blacks on moderate salt intake may be explained by a greater sensitivity to the proposed pathological effects of this mineral.