Adding salt to food as an indicator of gastric cancer risk among adults: A prospective study

Abstract

Abstract Background: While dietary salt intake has been linked with gastric cancer risk in Asian studies, findings from Western populations are sparse and limited to case-control studies. Methods: We evaluated associations between the frequency of adding salt to food and the risk of gastric cancer in a large prospective cohort of UK adults, the UK Biobank (N=471,144). Frequency of adding salt to food was obtained from a touchscreen questionnaire completed by participants at baseline (2006-2010). 24-h urinary sodium excretion was estimated using INTERSALT formulae. Cancer incidence was obtained by linkage to national cancer registries. Results: During the median 10.9 years of follow-up, 640 gastric cancer cases were recorded. In multivariable models, participants reporting adding salt to food “always” had a 41% higher risk of gastric cancer compared to participants who reported adding salt to food “never/rarely” (95%CI: +4%, +91%). There was a positive graded association between the frequency of adding salt to food and estimated 24-h urinary sodium. On the other hand, associations of estimated 24-h urinary sodium with gastric cancer were nonsignificant. Conclusions: “Always adding salt to food” was associated with a higher gastric cancer risk in a large sample of UK adults participating in the UK Biobank study compared to “never/rarely” adding salt to food. Frequency of adding salt to food can serve as a useful indicator of salt intake for surveillance purposes and a basis for devising easy-to-understand public health messages. Mini-abstract High frequency of adding salt to food was associated with a higher risk of gastric cancer among UK adults independent of age, sex, ethnicity, tobacco and alcohol use, prevalent morbidity, diet, or BMI. This is the first prospective study to show that frequently adding salt to food is related to higher gastric cancer risk in a western population. “Always adding salt to food” can serve as a simple indicator of excessive sodium intake for surveillance purposes and a basis for formulating public health messages aimed at gastric cancer prevention.