Dietary habits and risk of ovarian cancer death in a large-scale cohort study (JACC study) in Japan.

The Japan Collaborative Cohort (JACC) Study was established in 1988-1990 and consisted of 46,465 men and 64,327 women observed until the end of 2003. A self-administered food frequency questionnaire was used as a baseline survey, and associations of dietary habits with the risk of ovarian cancer death were evaluated, taking into consideration age, menstrual and reproductive, anthropometric, and lifestyle factors. During the observation period, 77 women died of ovarian cancer. Hazard ratios for dietary factors were calculated by Cox's proportional hazards model. Being adjusted only for age, high intakes of dried or salted fish and Chinese cabbage were positively associated with the risk of ovarian cancer death, and the risk increased dose-dependently. In contrast, intake of soybean curd (tofu) was inversely associated with the risk. After being adjusted for age and potential confounding factors, the results regarding the intakes of dried or salted fish and Chinese cabbage did not change. However, the significance relating to the intake of soybean curd (tofu) was attenuated. From the results of this cohort study, it was suggested that high intakes of dried or salted fish and Chinese cabbage were potential risk factors of ovarian cancer death. In contrast, however, a high intake of soy bean curd (tofu) might have preventive effects against the risk.