[Note: A large body of evidence – from 14 well-controlled trials involving 1,136 subjects – indicates green tea/green tea extract supports a significant average reduction of ‘bad’ cholesterol without reducing ‘good’ cholesterol.]
Green tea intake lowers fasting serum total and LDL [‘bad’] cholesterol in adults: A meta-analysis of 14 randomized controlled trials
– Source: American Journal of Clinical Nutrition, Aug 2011
By X Zheng, et al.
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 [‘bad’] cholesterol, and HDL [‘good’] 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 1,136 subjects were enrolled in our current meta-analysis.
Green tea consumption:
• Significantly lowered the total cholesterol concentration by 7.20 mg/dL (95% CI: ?8.19, ?6.21 mg/dL; P < 0.001)
• And significantly lowered the [bad] LDL-cholesterol concentration by 2.19 mg/dL (95% CI: ?3.16, ?1.21 mg/dL; P < 0.001).
• The mean [average] change in blood HDL [‘good’] 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 [the trial protocols & measures were similar/comparable]for total cholesterol, 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 total cholesterol and LDL [‘bad’] -cholesterol concentrations, but no effect on HDL [‘good’] cholesterol was observed.
Source: American Journal of Clinical Nutrition, Aug 2011; 94: 2 601-610. PMID: 21715508, by Zheng XX, Xu YL, Li SH, Liu XX, Hui R, Huang XH. Key Laboratory for Clinical Cardiovascular Genetics and Sino-German Laboratory for Molecular Medicine and the Department of Cardiology, Cardiovascular Institute and FuWai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.