Case-control study of diet and prostate cancer in China
Introduction: A higher incidence of prostate cancer is observed in the Western world than in Asian countries. Although it is relatively rare in China, an increased incidence has been reported in recent years. Studies in high-risk populations have suggested that dietary fat may play a role in enhancing the risk of developing prostate cancer. However, limited epidemiologic study has never examined the role of diet in low risk populations. Methods: A case-control study was conducted in 12 cities in China to evaluate the relationship between dietary factors and prostate cancer risk. We conducted personal interviews with 133 histopathologically confirmed prostate cancer cases diagnosed between 1989 to 1992 and 265 neighborhood controls of similar age. Results: Cases were more likely than controls to consume food with high fat and from animal sources (p<0.01). The daily fat intake and the percentage of energy from fat were statistically significantly higher among cases than among controls (p<0.01). The adjusted odds ratio for total fat between lowest quartiles and highest quartiles was OR=3.6 (95percent C.I. 1.8-7.2); for saturated fat, OR=2.9 (95percent C.I. 1.5- 5.7); and for unsaturated fat, OR=3.3 (95percent C.I. 1.7- 6.3). Discussion: The data suggest that dietary fat, both saturated and unsaturated, are associated with an increased risk for prostate cancer in a low risk population.