Salt taste sensitivity, physical activity and gastric cancer.

BACKGROUND Gastric cancer is a major health issue in China. Risk factors are mainly related to nutrition and environment, with a particular role for high salt intake. The salt taste sensitivity threshold (STST) can influence salt consumption, and is therefore assumed to have association with gastric cancer. It was therefore assessed, together with other lifestyle factors, in the present study in China. METHODS A 1:2 matched hospital based case-control study, including 300 cases with a new histological confirmed diagnosis of gastric cancer and 600 controls that were cancer and gastric disease free, was conducted. A self-designed questionnaire was employed to collect information on dietary and lifestyle habit, including physical activity, and a salt taste sensitivity test was used to measure the STST for all subjects. Conditional logistic regression was used to calculated odds ratios (ORs) and 95% confidence intervals (95% CI). RESULTS An increased risk of gastric cancer was found related to smoking, alcohol drinking, family history of cancer and consumption of salted food. Walking and sports activity (adjusted OR=0.69(0.51-0.99) for ≥4 times/week) exerted protective effects. A significant positive association between increased STST and gastric cancer was evident, with an adjusted OR of 2.05 (1.68-2.5). When we used STST≥5 as a cut-off, the affected subjects were at 5.71 times greater risk of gastric cancer than those with STST　below 5. STST showed a moderate correlation with physical activity (Correlation coefficient =0.22). The cut point of STST≥5 had a best sensitivity and specificity for predicting gastric cancer risk (sensitivity for 73.7%, specificity of 57%). CONCLUSION Salt and salted food intake is associated with gastric cancer, while physical activity is protective. A high STST is strongly linked to gastric cancer risk.