Several studies have indicated the association between intake of foods high in dietary glycemic index (GI) and glycemic load (GL) with an increased risk of digestive tract cancers. We hypothesized that GI and GL may be associated with risk of esophageal squamous cell carcinoma (ESCC) in a high-risk population in Iran. In total, we interviewed 47 cases with incident of ESCC and 96 frequency-matched hospital controls, then calculated the average dietary GI and GL via a validated food frequency questionnaire. Dietary GL was calculated as a function of GI, carbohydrate content, and frequency of intake of certain foods. Dietary GI and GL levels were significantly higher among the ESCC cases compared with the controls (P < .05). After adjustment for potential confounders, those in the highest tertile of dietary GI had 2.95 times higher risk of ESCC compared with those in the lowest (95% confidence interval, 1.68-3.35; P for trend = .002). In addition, being in the highest tertile of dietary GL was positively associated with an ESCC risk (odds ratio, 3.49; 95% confidence interval, 2.98-4.41; P for trend = .001). Findings of the present study indicate that diets with high GI and GL might have potentially unfavorable effects on ESCC risk and suggest a possible role for excess circulating insulin and related insulin-like growth factor 1 in esophageal cancer development.
Keywords: BMI; CIs; Carbohydrate; Case control; EC; ESCC; Esophageal squamous cell carcinoma; FCT; FFQ; Fiber; GERD; GI; GL; Glycemic index; Glycemic load; IGF-1; ORs; US Department of Agriculture; USDA; body mass index; confidence intervals; esophageal cancer; esophageal squamous cell carcinoma; food composition table; food frequency questionnaire; gastroesophageal reflux disease; glycemic index; glycemic load; insulin-like growth factor 1; odds ratios.