Re: Consumption of Fish Products across the Lifespan and Prostate Cancer Risk

Abstract

Objective: To examine whether fish and fish oil consumption across the lifespan is associated with a lower risk of prostate cancer. Design: The study was nested among 2268 men aged 67–96 years in the AGES-Reykjavik cohort study. In 2002 to 2006, dietary habits were assessed, for early life, midlife and later life using a validated food frequency questionnaire. Participants were followed for prostate cancer diagnosis and mortality through 2009 via linkage to nationwide cancerand mortality registers. Adjusting for potential confounders, we used regression models to estimate odds ratios (ORs) and hazard ratios (HRs) for prostate cancer according to fish and fish oil consumption. Results: Among the 2268 men, we ascertained 214 prevalent and 133 incident prostate cancer cases, of which 63 had advanced disease. High fish consumption in earlyand midlife was not associated with overall or advanced prostate cancer. High intake of salted or smoked fish was associated with a 2-fold increased risk of advanced prostate cancer both in early life (95% CI: 1.08, 3.62) and in later life (95% CI: 1.04, 5.00). Men consuming fish oil in later life had a lower risk of advanced prostate cancer [HR (95%CI): 0.43 (0.19, 0.95)], no association was found for early life or midlife consumption. Conclusions: Salted or smoked fish may increase risk of advanced prostate cancer, whereas fish oil consumption may be protective against progression of prostate cancer in elderly men. In a setting with very high fish consumption, no association was found between overall fish consumption in early or midlife and prostate cancer risk. Citation: Torfadottir JE, Valdimarsdottir UA, Mucci LA, Kasperzyk JL, Fall K, et al. (2013) Consumption of Fish Products across the Lifespan and Prostate Cancer Risk. PLoS ONE 8(4): e59799. doi:10.1371/journal.pone.0059799 Editor: Zoran Culig, Innsbruck Medical University, Austria Received October 11, 2012; Accepted February 19, 2013; Published April 17, 2013 Copyright: 2013 Torfadottir et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: Support was received from Framfor (Progress), an Icelandic organization that aims to fund research and education initiatives related to prostate cancer (to JET), the Icelandic Cancer Society (to JET), HELGA: Nordic Centre of Excellence, Nordic Health Whole Grain Food (to JET and JLK), in part by training grant NIH 5 T32 CA09001-36 (to JLK) and by the American Institute for Cancer Research (to JLK). This study was also funded in part by the National Institute on Aging contract N01-AG-1-2100, in part by the Intramural Research Program of the National Institute on Aging, the Icelandic Heart Association, and the Althingi (the Icelandic Parliament). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: jet@hi.is