Carbohydrate consumption and esophageal cancer: An ecological assessment

OBJECTIVES: The incidence of esophageal adenocarcinoma is on the rise in the United States. In this ecological study using the Surveillance, Epidemiology, and End Results (SEER) program (1973-2001) and national food consumption data (1909-1997), we evaluated the correlation between secular trends of dietary macronutrient intakes and esophageal cancer rates. METHODS: Linear regressions were performed to assess the correlation between age-adjusted incidence rates of esophageal cancers and nutrients. RESULTS: The increase in esophageal adenocarcinoma was found to be strongly correlated with the rise in carbohydrate intake (P < 0.0001). The decline in squamous cell carcinoma rates was negatively correlated with carbohydrate intake in the univariate model (P < 0.0001), but this correlation disappeared when adjusted for other nutrients. Correlations of esophageal adenocarcinoma to percentage of calories from corn syrup, representing refined carbohydrates, were statistically significant in the univariate model (P < 0.0001), but decreased in significance in the multivariate model (P = 0.0118). We also found a significant correlation between obesity and esophageal adenocarcinoma (P < 0.0001) during the same time period. CONCLUSION: Our ecological evaluation suggests that high carbohydrate intake and obesity can account for at least some of the rise in esophageal adenocarcinoma. Within-population studies are needed to clarify these trends.