Esophageal cancer is the eighth most common malignancy and the sixth leading cause of cancer-related deaths worldwide. Furthermore, the incidence is increasing in developed countries. To determine whether soyfood intake affects the risk of esophageal cancer, Chinese researchers determined the relationship between soy and isoflavone intake and risk of this cancer in a high-esophageal cancer region of China. This study, which involved 359 cancer patients and 380 hospital-based controls found that patients consumed significantly less total soy than controls (mean 83.3 vs 57.2 g/d). Information on soy intake was obtained by personal interview. Furthermore, the adjusted odds ratio was 0.33 when comparing those in the third soyfood intake tertile with those in the first. Inverse associations with apparent dose-response relationships were also found between isoflavone intakes and esophageal cancer risk. Since this study involved Chinese participants, it is unlikely soy was simply a marker for a more healthful diet. Thus, the results suggest fairly modest soy intakes may be protective against esophageal cancer.
Tang L, Lee AH, Xu F, et al. Soya and isoflavone intakes associated with reduced risk of oesophageal cancer in north-west China. Public Health Nutr 2014;1-5.