Dietary Fish and n-3 Polyunsaturated Fatty Acid Consumption, and Renal Cell Carcinoma Risk in Japan: The Japan Public Health Center-Based Prospective Study.

Background: Previous epidemiologic studies found inconsistent associations between fish consumption and renal cell carcinoma (RCC). Although the consumption of n-3 polyunsaturated fatty acids (PUFA) was reported to protect against the development of some types of cancer, little is known regarding its association with RCC.
Methods: We investigated the association between fish and n-3 PUFA consumption and RCC risk using the Japan Public Health Center-based Prospective Study. We examined data from 84,063 eligible Japanese participants aged 45 to 74 years who responded to a validated food frequency questionnaire for Cohort I in 1995 and Cohort II in 1998. The participants were followed-up until 2013. HRs and 95% confidence intervals (CI) were estimated using a multivariable-adjusted Cox proportional hazard model, and the exposure level was categorized into quartiles.
Results: Among the 1,272,298 person-years of follow-up, 262 cases of newly diagnosed RCC were identified. The multivariate-adjusted HRs for the highest vs. lowest quartile of fish, including shellfish, were (HR = 1.43; 95% CI, 0.98-2.07) and the individual marine n-3 PUFAs were (HR = 1.56; 95% CI, 1.07-2.28; Ptrend = 0.09) for eicosapentenoic acid, (HR = 1.81; 95% CI, 1.27-2.59; Ptrend = 0.01) for docosapentaenoic acid, and (HR = 1.56; 95% CI, 1.07-2.27; Ptrend = 0.09) for docosahexaenoic acid. RCC were further categorized on the basis of diagnosis methods and cancer stage, and the positive correlation did not change substantially.
Conclusions: We demonstrated that high consumption of n-3 PUFA is associated with RCC risk.
Impact: The positive association between n-3 PUFA and RCC risk was observed in Japanese who consume higher amounts of fish than Western populations.
(©2023 American Association for Cancer Research.)