Dietary intakes of trace elements and the risk of kidney cancer: the Singapore Chinese Health Study

Abstract

Background: Epidemiological studies have demonstrated separately that patients with kid ney stone may have higher dietary intake of zinc and higher risk of developing kidney can cer. We prospectively assessed the associations of dietary zinc and other trace elements with kidney cancer risk for the first time. Methods: We used data from the prospective Singapore Chinese Health Study that recruited 63,257 adult Chinese residing in Singapore between 1993 and 1998. A validated food frequency questionnaire and the Singapore Food Composition Database was used to compute the values of intake for zinc, copper and manganese. We identified incident cancer cases via linkage with nationwide cancer registry, and used Cox proportional hazard models to compute hazard ratio (HR) and 95% confidence interval (CI) for the association with kid ney cancer risk. Results: There were 229 incident kidney cancer cases after median follow-up of 20.1 years. Dietary zinc intake was positively associated with higher kidney cancer risk; the HR compar ing the extreme quartiles of zinc intake was 1.74 (95% CI: 1.02-2.97; P-trend ¼ 0.033). Conversely, intakes of copper and manganese were not associated with kidney cancer risk. Conclusions: The positive association between dietary zinc and risk of kidney cancer sug gests that zinc may be implicated in renal carcinogenesis.