Alireza Sadeghi - Department of Cellular and Molecular Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences (TUMS), Tehran, Iran

Background and Aim: Several studies have evaluated the association between coffee, black and green tea consumption and non-Hodgkin’s lymphomas (NHL) risk, while the results were inconsistent. We conducted a dose-response meta-analysis of available observational studies to assess the association between coffee, black and green tea intake and the risk of NHL in the general population.Methods: Studies published up to June 2018 were identified on the basis of a literature search in PubMed, ISI Web of Science, Scopus, Cochrane and Google scholar databases using Mesh and non-Mesh relevant keywords. Relative risks (RRs) with 95% confidence intervals (CIs) and the dose-response relationships were calculated using random-effects models. Results: In the meta-analysis of nineteen effect sizes, we found that higher green tea intake was associated with a 39% reduced risk of NHL (pooled RR: 0.61; 95% CIs 0.38-0.99, I2=60.4%, pheterogeneity=0.080) in high versus low intake meta-analysis. No association was observed between coffee intake (pooled RR: 1.21; 95% CIs 0.97-1.50, I2=52.6%, pheterogeneity<0.05), black tea intake (RR: 1.01; 95% CI 0.82 to 1.24, I2=0%, pheterogeneity=0.875) and risk of NHL in high versus low intake meta-analysis. Conclusion: Findings from this dose-response meta-analysis indicate that green tea intake higher than ~3.5 cups/day is negatively associated with NHL risk.

Coffee, Tea, non-Hodgkin’s lymphomas, systematic review, meta-analysis