Xin-Xin Zheng1, Yan-Lu Xu, Shao-Hua Li, Xu-Xia Liu, Rutai Hui, Xiao-Hong Huang. 1. Key Laboratory for Clinical Cardiovascular Genetics and Sino-German Laboratory for Molecular Medicine, Cardiovascular Institute, FuWai Hospital, Chinese Academy of Medical Sciences, Beijing, China.
Abstract
BACKGROUND: The effect of green tea beverage and green tea extract on lipid changes is controversial. OBJECTIVE: We aimed to identify and quantify the effect of green tea and its extract on total cholesterol (TC), LDL cholesterol, and HDL cholesterol. DESIGN: We performed a comprehensive literature search to identify relevant trials of green tea beverages and extracts on lipid profiles in adults. Weighted mean differences were calculated for net changes in lipid concentrations by using fixed-effects or random-effects models. Study quality was assessed by using the Jadad score, and a meta-analysis was conducted. RESULTS: Fourteen eligible randomized controlled trials with 1136 subjects were enrolled in our current meta-analysis. Green tea consumption significantly lowered the TC concentration by 7.20 mg/dL (95% CI: -8.19, -6.21 mg/dL; P < 0.001) and significantly lowered the LDL-cholesterol concentration by 2.19 mg/dL (95% CI: -3.16, -1.21 mg/dL; P < 0.001). The mean change in blood HDL-cholesterol concentration was not significant. Subgroup and sensitivity analyses showed that these changes were not influenced by the type of intervention, treatment dose of green tea catechins, study duration, individual health status, or quality of the study. Overall, no significant heterogeneity was detected for TC, LDL cholesterol, and HDL cholesterol; and results were reported on the basis of fixed-effects models. CONCLUSION: The analysis of eligible studies showed that the administration of green tea beverages or extracts resulted in significant reductions in serum TC and LDL-cholesterol concentrations, but no effect on HDL cholesterol was observed.
BACKGROUND: The effect of green tea beverage and green tea extract on lipid changes is controversial. OBJECTIVE: We aimed to identify and quantify the effect of green tea and its extract on total cholesterol (TC), LDL cholesterol, and HDL cholesterol. DESIGN: We performed a comprehensive literature search to identify relevant trials of green tea beverages and extracts on lipid profiles in adults. Weighted mean differences were calculated for net changes in lipid concentrations by using fixed-effects or random-effects models. Study quality was assessed by using the Jadad score, and a meta-analysis was conducted. RESULTS: Fourteen eligible randomized controlled trials with 1136 subjects were enrolled in our current meta-analysis. Green tea consumption significantly lowered the TC concentration by 7.20 mg/dL (95% CI: -8.19, -6.21 mg/dL; P < 0.001) and significantly lowered the LDL-cholesterol concentration by 2.19 mg/dL (95% CI: -3.16, -1.21 mg/dL; P < 0.001). The mean change in blood HDL-cholesterol concentration was not significant. Subgroup and sensitivity analyses showed that these changes were not influenced by the type of intervention, treatment dose of green tea catechins, study duration, individual health status, or quality of the study. Overall, no significant heterogeneity was detected for TC, LDL cholesterol, and HDL cholesterol; and results were reported on the basis of fixed-effects models. CONCLUSION: The analysis of eligible studies showed that the administration of green tea beverages or extracts resulted in significant reductions in serum TC and LDL-cholesterol concentrations, but no effect on HDL cholesterol was observed.