Ethnic patterns of salt purchase in Houston, Texas.

Dietary sodium may play a contributory role in the development of hypertension, but difficulties in defining the "usual" sodium intake of individuals prevent any stronger statement on the nature of the diet-disease relationship. The prevelance of hypertension is greater in black than in white populations of the United States, and there is speculation that dietary sodium intake may also be greater in black individuals. A significant proportion of dietary sodium is derived from table salt added to food during its preparation and consumption. In an attempt to identify whether purchase of table salt was sufficiently increased in black communities to support the hypothesis of an etiologic role in hypertension, the scales of table salt in supermarkets located in predominantly black, Hispanic and white census tracts of Houston, Texas, were compared. The mean ratio between sales of salt and a series of 20 staple food commodities in predominantly black and Hispanic census tract supermarkets were 148% and 202%, respectively, of that in predominantly white census tracts. The elevated ratios were not due to reduced sales of the food commodities. The authors conclude that sales of table salt, in relation to the series of food commodities, are 50-100% higher in Houston's black and Hispanic census tract supermarkets than in those of white census tracts. Whether the increased sales of table salt have causal relationship to the prevalence of hypertension in these communities can only be determined by further studies.