Historical studies by Dahl demonstrated a positive correlation between dietary salt intake and the prevalence of hypertension across different populations.
was a physician whose first work was clinical in nature. One of Dahl's earliest studies involving the association of salt (NaCl) and hypertension was conducted using groups of employees at Brookhaven National Laboratory in Long Island, NY. This work demonstrated that for employees classified on the basis of a survey of eating habits as low, intermediate, or high salt intake, the percentage of individuals with hypertension in each group was positively correlated with salt intake (15). A more dramatic correlation between actual average daily NaCl intake and the percentage of individuals with hypertension in five geographically defined populations from around the world Inuit (termed "Eskimos" in the original publication) (Alaska), Marshall Islanders (Pacific), Americans (Northern United States), Japanese (Southern Japan), and Japanese (Northern Japan) was reported by Dahl in 1960 (7, 8).
Rapp et al. (Mon,) studied this question.