1. ¹Chia Nan University of Pharmacy and Science, 60 Erh-Jen Road, Jen Te, Tainan, Taiwan 717, Taiwan
2. ²Institutes of Environmental Health, National Taiwan University College of Public Health, Taipei, Taiwan 100, Taiwan
3. ³Preventive Medicine, National Taiwan University College of Public Health, Taipei, Taiwan 100, Taiwan
4. ⁴Department of Urology, National Taiwan University College of Medicine, 1 Jen-Ai Road Section 1, Taipei, Taiwan 100, Taiwan
5. ⁵Institute of Environmental Health, China Medical University College of Public Health, 91 Hsueh-Shih Road, Taichung, Taiwan 404, Taiwan

Correspondence: Dr F-C Sung, Institute of Environmental Health, China Medical University College of Public Health, 91 Hsueh Shih Road, Taichung, Taiwan 404, Taiwan. E-mail: fcsung@mail.cmu.edu.tw, sung@ha.mc.ntu.edu.tw

Revised 20 July 2005; Accepted 17 August 2005; Published online 4 October 2005.

Abstract

In a case–control study in a veterans hospital in Taiwan, we compared 237 histology-confirmed prostate carcinoma cases with 481 controls, frequency matched by age, for their consumption of vegetarian food, namely soybean products, rice, wheat protein and other vegetables. The multivariable logistic regression analysis showed a significant association with such food (odds ratio (OR)=0.67, 95% confidence interval (CI)=0.47, 0.94). This beneficial effect presented for men with body mass index (BMI) 25 kg m^-2 (OR=0.50, 95% CI=0.32, 0.76) but not for men with greater BMI. The OR of prostate carcinoma for men with BMI 25 kg m^-2 was 1.74 (95% CI=1.21, 2.51), compared with men with higher BMI (>25 kg m^-2). Other significant risk factors associated with the disease included higher income (OR=2.40, 95% CI=1.07, 5.42), physical activity (OR=1.75, 95% CI=1.08, 2.83), being married (OR=2.49, 95% CI=1.40, 4.43) and coffee consumption (OR=1.88, 95% CI=1.07, 3.30). Stratified analysis also showed that the consumption of fish/shellfish had an adverse association for men with higher BMI. This study suggests that the intake of the low fat local vegetarian food has a protective effect against prostate carcinoma for thin men in this study population.