Long-term fatty fish consumption and renal cell carcinoma incidence in women

Context: The epidemiological evidence that fatty fish consumption may be associated with the lower risk of several cancers is not consistent and no studies of renal cell carcinoma (RCC) exist.

Objective: To examine the association between fatty and lean fish consumption and risk of RCC in women.

Design, setting, and participants: The Swedish Mammography Cohort, a population-based prospective cohort study of 61,433 women aged 40 to 76 years without previous diagnosis of cancer at baseline (March 1, 1987-December 14, 1990). Participants filled in a food frequency questionnaire at baseline and in September 1997.

Main outcome measure: Incident renal cell carcinoma.

Results: During a mean of 15.3 years (940,357 person-years) of follow-up between 1987 and 2004, 150 incident RCC cases were diagnosed. After adjustment for potential confounders, an inverse association of fatty fish consumption with the risk of RCC was found (P for trend = .02), but no association was found with lean fish consumption. Compared with no consumption, the multivariate rate ratio (RR) was 0.56 (95% confidence interval [CI], 0.35-0.91) for women eating fatty fish once a week or more. Compared with women consistently reporting no fish consumption, the multivariate RR was 0.26 (95% CI, 0.10-0.67) for those women reporting consistent consumption of fatty fish at baseline and 1997 (based on a subset of 36 664 women who filled in the baseline and 1997 questionnaires, with 40 incident RCC cases during the 1998-2004 follow-up period).

Conclusion: Our study suggests that consumption of fatty fish may reduce the occurrence of RCC in women.