Public Health Nutrition: 12(5), 609–613 doi:10.1017/S1368980008003182 Fish intake and the risk of fatal prostate cancer: findings from a cohort study in Japan Truong-Minh Pham 1,2, *, Yoshihisa Fujino 1 , Tatsuhiko Kubo 3 , Reiko Ide 4 , Noritaka Tokui 5 , Tetsuya Mizoue 6 , Itsuro Ogimoto 7 , Shinya Matsuda 1 and Takesumi Yoshimura 8 1 Department of Preventive Medicine and Community Health, School of Medicine, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-ku, Kitakyushu-shi 807-8555, Japan: 2 Thai Nguyen Medical College, Thai Nguyen University, Thai Nguyen, Vietnam: 3 Asahi Kasei Nobeoka Office Health Care Center, Miyazaki, Japan: 4 Department of Work Systems and Health, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan: 5 Department of Preventive Medicine and Dietetics, Institute of Industrial Ecological Sciences, University of Occupational and Environmental Health, Kitakyushu, Japan: 6 Department of Epidemiology, Research Institute, International Medical Center of Japan, Tokyo, Japan: 7 Department of Public Health, School of Medicine, Kurume University, Kurume, Japan: 8 Fukuoka Institute of Health and Environmental Sciences, Fukuoka, Japan Submitted 13 June 2007: Accepted 2 May 2008: First published online 29 July 2008 Abstract Objective: We investigated the relationship between the intake of fish and the risk of death from prostate cancer. Design: Data were derived from a prospective cohort study in Japan. Fish con- sumption obtained from a baseline questionnaire was classified into the two categories of ‘low intake’ and ‘high intake’. The Cox proportional hazards model was used to estimate hazard ratios (HR) and 95 % confidence intervals. Subjects: Data for 5589 men aged 30–79 years were analysed. Results: A total of twenty-one prostate cancer deaths were observed during 75 072 person-years of follow-up. Mean age at baseline study of these twenty-one subjects was 67?7 years, ranging from 47 and 79 years old. Results showed a consistent inverse association of this cancer between the high v. low intake groups. The multivariate model adjusted for potential confounding factors and some other food items showed a HR of 0?12 (95% CI 0?05, 0?32) for the high intake group of fish consumption. Conclusions: These results support the hypothesis that a high intake of fish may decrease the risk of prostate cancer death. Given the paucity of studies examining the association between prostate cancer and fish consumption, particularly in Asian populations, these findings require confirmation in additional cohort studies. Keywords Cohort study Fish intake Mortality Prostate cancer Both the incidence of and mortality from prostate cancer vary substantially, from high in the USA and certain Western countries to considerably low in Asian countries such as China, Singapore and Japan (1) . Recently, how- ever, these rates appear to have increased in Japan (2,3) . Among risk factors for prostate cancer, advanced age and family history appear to be strong determinants (4) . There is evidence that the incidence is increased notably in Japanese migrants living in Hawaii and is far higher than that among Japanese men living in Japan (5,6) . Environ- mental factors such as dietary habits may therefore play an important role in the causation of prostate cancer. A review article (7) recently summarized the results from cohort and case–control studies examining the associa- tion between fish intake and risk of prostate cancer incidence or mortality, but could not provide conclusive evidence of this association. However, none of the studies quoted showed an increased risk of prostate cancer with high intake of fish, and some have suggested that a high intake of fish reduces the risk of prostate cancer (8,9) . Others have reported that n-3 fatty acids, which are found mainly in fish, may reduce the risk of prostate cancer (10,11) . These studies have been conducted mainly in American and Western countries, however, and the few studies conducted in Japan have yielded inconsistent findings (12,13) . Thus we conducted a prospective study in Japan to investigate whether a high intake of fish is protective against the risk of prostate cancer mortality. Methods Study population Study subjects were the participants of the Miyako Study, a cohort study conducted in four areas of Fukuoka Pre- fecture, Japan. Details of the present cohort study have *Corresponding author: Email ptrminh@med.uoeh-u.ac.jp; ptrminh@yahoo.fr r The Authors 2008