An inverse association between preserved fish and prostate cancer: results from a population-based case-control study in Canada. 
Epidemiological studies suggest that fish consumption may be a protective factor against the development of prostate cancer.  We investigated the association between prostate cancer risk and fresh and preserved fish consumption among participants of a population-based case-control study (1,534 cases, 1,607 controls).  Fish intake was measured using a dietary questionnaire that collected both frequency of consumption of a given portion size.  Logistic regression analysis demonstrated an inverse association between preserved fish and prostate cancer risk for all levels of consumption, but reductions only reached statistical significance for the category of 1 to 3 servings of preserved fish per month (odds ratio = 0.78, confidence interval = 0.64-0.95).  Consumption of any fat or energy from preserved fish was also associated with reduced risk.  There was no suggestion of reduced prostate cancer risk with consumption of fresh and canned fish.  Our results suggest that consumption of preserved fish may reduce the risk of developing prostate cancer.