Green tea consumption and glutathione S-transferases genetic polymorphisms on the risk of adult leukemia

Purpose: Green tea may have a beneficial role of inhibiting leukemia. Glutathione S-transferases (GSTs) are known to detoxify certain carcinogens. We investigated the roles of green tea consumption and polymorphisms of GSTM1, GSTT1 and GSTP1 on the risk of adult leukemia, and to determine whether the associations varied within GSTs genotypes. Methods: A multicenter case–control study was conducted in China, 2008–2013. It comprised 442 incident, hematologically confirmed adult leukemia cases and 442 outpatient controls, individually matched to cases by gender, birth quinquennium and study site. Data were collected by face-to-face interview using a validated questionnaire. Genetic polymorphisms were assayed by PCR. Results: An inverse association between green tea consumption and adult leukemia risk was observed. Compared with non-tea drinkers, the adjusted odds ratios (95 % confidence intervals) were 0.50 (0.27–0.93), 0.31 (0.17–0.55) and 0.53 (0.29–0.99) for those who, respectively, consumed green tea >20 years, ≥2 cups daily and dried tea leaves >1000 g annually. In assessing the associations by GSTs genotypes, risk reduction associated with green tea consumption was stronger in individuals with the GSTT1-null genotype (OR 0.24; 95 % CI 0.11–0.53) than GSTT1-normal carriers (OR 0.67; 95 % CI 0.42–1.05; P interaction = 0.02). GSTM1 and GSTP1 did not significantly modify the inverse association of leukemia with green tea. Conclusions: The results suggest that regular daily green tea consumption may reduce leukemia risk in Chinese adults regardless of GSTM1 and GSTP1 polymorphic status. The association between green tea and adult leukemia risk varied with GSTT1 genotype and highlights further study.