[Note: Evidence from 14 well-controlled trials involving 1,136 subjects
indicates green tea or 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
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 analysis 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.
Resource
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
Sino-German Laboratory for Molecular Medicine
Department of Cardiology, Cardiovascular Institute
FuWai Hospital, Chinese Academy of Medical Sciences
Peking Union Medical College, Beijing, China.
Green tea intake lowers fasting serum total and LDL [‘bad’] cholesterol in adults: A meta-analysis of 14 randomized controlled trials
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 analysis 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.
Resource
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
Sino-German Laboratory for Molecular Medicine
Department of Cardiology, Cardiovascular Institute
FuWai Hospital, Chinese Academy of Medical Sciences
Peking Union Medical College, Beijing, China.
