Dietary catechins and epithelial cancer incidence: The Zutphen elderly study

The flavonoids, a group of more than 4,000 polyphenolic antioxidants, are p otential cancer preventive components of fruits and vegetables. Catechins, one of the 6 major groups of flavonoids, are present in high concentrations in tea as well. Our objective was to evaluate the association between inta ke of catechins and incidence of epithelial cancers with data from the Zutp hen Elderly Study, a prospective cohort study among 728 men aged 65-84 year s in 1985. The average catechin intake at baseline was 72 mg/day (range, 0- 355 mg/day). After 10 years of follow-up, 96 incident epithelial cancers we re recorded, including 42 cases of lung cancer. After multivariate adjustme nt, catechin intake was not associated with epithelial cancer (risk ratio [ RR] from lowest to highest tertile: 1.00, 0.75, 0.94; p for trend: 0.82), o r lung cancer (RR from lowest to highest tertile: 1.00, 0.72, 0.92; P for t rend: 0.80). Catechins not from tea were borderline significantly inversely associated with lung cancer incidence (RR and 95% confidence interval [CI] for a 7.5-mg increase in intake: 0.66, 0.42-1.05), whereas catechins from tea were not. Catechins from apple, the major source of non-tea catechins, were also related to lung cancer incidence (RR and 95% CI for a 7.5-mg cate chin increase: 0.67, 0.38-1.17). Because tea, the major catechin source in this population, was not associated with cancer risk, it seems unlikely tha t catechins are responsible for the observed inverse trend be tween non-tea catechins and lung cancer incidence. However, differences in bioavailabili ty of the various catechins may play a role; effects on individual cancer s ites cannot be excluded and merit further investigation. (C) 2001 Wiley-Lis s, Inc.