Salt and gastric cancer: a case-control study in Puerto Rico.

A total of 136 incident intestinal type gastric cancer cases and 151 age-comparable population controls were interviewed in Puerto Rico about their dietary habits with special emphasis on dietary salt consumption. All interviews were conducted at home using a quantitative dietary frequency instrument. The weekly intake of foods was estimated from the reported frequency of consumption and portion size according to a food model. The dietary salt exposure was estimated from the intake of nine selected food items which are highly salted food items commonly consumed in Puerto Rico. A strong (odds ratio [OR] = 3.34) and statistically significant (P < 0.001) unadjusted difference was found between cases and controls regarding dietary salt exposure. A statistically significant dose response for the index of salt exposure and gastric cancer was also found. The association remained positive and statistically significant after simultaneously adjusting for the confounding effects of sex, education and cigarette smoking.