Limits...
Effect of green tea consumption on blood pressure: a meta-analysis of 13 randomized controlled trials.

Peng X, Zhou R, Wang B, Yu X, Yang X, Liu K, Mi M - Sci Rep (2014)

Bottom Line: The studies investigating the effects of green tea on blood pressure (BP) have generated inconsistent results.Subgroup analyses further suggested that the positive effect of green tea polyphenols on BP was only showed in studies using a low-dose green tea polyphenol, with the long-term intervention duration or ruling out the confounding effects of caffeine.The meta-analysis suggested that green tea consumption had a favorable effect on decrease of BP.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Epidemiology and Health Statistics, Institute of Public Health, Chengdu Medical College, Chengdu 610083, Sichuan, China [2] Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, China [3].

ABSTRACT
The studies investigating the effects of green tea on blood pressure (BP) have generated inconsistent results. The aim of this study is to quantitatively evaluate the effects of green tea on BP control. PubMed, Embase, and the Cochrane Library (updated to March 2014) were searched for randomized controlled trials evaluating the effects of green tea on BP. Pooled effect of green tea consumption on BP was evaluated using fixed-effects or random-effects model. Thirteen trials comprising a total of 1,367 subjects were included in the current meta-analysis. The overall outcome of the meta-analysis suggested that green tea consumption significantly decrease systolic blood pressure (SBP) level by -1.98 mmHg (95% CI: -2.94, -1.01 mmHg; P < 0.001). Compared with the control group, green tea also showed a significant lowering effect on diastolic blood pressure (DBP) in treatment group (-1.92 mmHg; 95% CI: -3.17, -0.68 mmHg; P = 0.002). Subgroup analyses further suggested that the positive effect of green tea polyphenols on BP was only showed in studies using a low-dose green tea polyphenol, with the long-term intervention duration or ruling out the confounding effects of caffeine. The meta-analysis suggested that green tea consumption had a favorable effect on decrease of BP.

Show MeSH

Related in: MedlinePlus

Meta-analysis of effects of green tea on diastolic blood pressure (DBP).Weight was assigned with STATA (Version 11; StataCorp, College Station, TX) by using number of subjects and SD. Sizes of data markers indicate the weight of each study in this analysis. The diamond represents the overall estimated effect and the result was obtained from a random-effects model. WMD, weighted mean difference.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4150247&req=5

f3: Meta-analysis of effects of green tea on diastolic blood pressure (DBP).Weight was assigned with STATA (Version 11; StataCorp, College Station, TX) by using number of subjects and SD. Sizes of data markers indicate the weight of each study in this analysis. The diamond represents the overall estimated effect and the result was obtained from a random-effects model. WMD, weighted mean difference.

Mentions: As shown in Fig. 2, a significant reduction in SBP was observed in subjects supplemented with green tea (−1.98 mmHg; 95% CI, −2.94 to −1.01 mmHg; P < 0.001) when compared with control subjects. The mean difference in DBP was reported in 13 trials and was found to be significantly different (−1.92 mmHg; 95% CI, −3.17 to −0.68 mmHg; P = 0.002; Fig. 3). In addition, no significant differences were detected when we used the different model to pooling the data (Supplementary Fig. S1 and Fig. S2 online).


Effect of green tea consumption on blood pressure: a meta-analysis of 13 randomized controlled trials.

Peng X, Zhou R, Wang B, Yu X, Yang X, Liu K, Mi M - Sci Rep (2014)

Meta-analysis of effects of green tea on diastolic blood pressure (DBP).Weight was assigned with STATA (Version 11; StataCorp, College Station, TX) by using number of subjects and SD. Sizes of data markers indicate the weight of each study in this analysis. The diamond represents the overall estimated effect and the result was obtained from a random-effects model. WMD, weighted mean difference.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150247&req=5

f3: Meta-analysis of effects of green tea on diastolic blood pressure (DBP).Weight was assigned with STATA (Version 11; StataCorp, College Station, TX) by using number of subjects and SD. Sizes of data markers indicate the weight of each study in this analysis. The diamond represents the overall estimated effect and the result was obtained from a random-effects model. WMD, weighted mean difference.
Mentions: As shown in Fig. 2, a significant reduction in SBP was observed in subjects supplemented with green tea (−1.98 mmHg; 95% CI, −2.94 to −1.01 mmHg; P < 0.001) when compared with control subjects. The mean difference in DBP was reported in 13 trials and was found to be significantly different (−1.92 mmHg; 95% CI, −3.17 to −0.68 mmHg; P = 0.002; Fig. 3). In addition, no significant differences were detected when we used the different model to pooling the data (Supplementary Fig. S1 and Fig. S2 online).

Bottom Line: The studies investigating the effects of green tea on blood pressure (BP) have generated inconsistent results.Subgroup analyses further suggested that the positive effect of green tea polyphenols on BP was only showed in studies using a low-dose green tea polyphenol, with the long-term intervention duration or ruling out the confounding effects of caffeine.The meta-analysis suggested that green tea consumption had a favorable effect on decrease of BP.

View Article: PubMed Central - PubMed

Affiliation: 1] Department of Epidemiology and Health Statistics, Institute of Public Health, Chengdu Medical College, Chengdu 610083, Sichuan, China [2] Research Center for Nutrition and Food Safety, Institute of Military Preventive Medicine, Third Military Medical University, Chongqing Key Laboratory of Nutrition and Food Safety, Chongqing Medical Nutrition Research Center, Chongqing 400038, China [3].

ABSTRACT
The studies investigating the effects of green tea on blood pressure (BP) have generated inconsistent results. The aim of this study is to quantitatively evaluate the effects of green tea on BP control. PubMed, Embase, and the Cochrane Library (updated to March 2014) were searched for randomized controlled trials evaluating the effects of green tea on BP. Pooled effect of green tea consumption on BP was evaluated using fixed-effects or random-effects model. Thirteen trials comprising a total of 1,367 subjects were included in the current meta-analysis. The overall outcome of the meta-analysis suggested that green tea consumption significantly decrease systolic blood pressure (SBP) level by -1.98 mmHg (95% CI: -2.94, -1.01 mmHg; P < 0.001). Compared with the control group, green tea also showed a significant lowering effect on diastolic blood pressure (DBP) in treatment group (-1.92 mmHg; 95% CI: -3.17, -0.68 mmHg; P = 0.002). Subgroup analyses further suggested that the positive effect of green tea polyphenols on BP was only showed in studies using a low-dose green tea polyphenol, with the long-term intervention duration or ruling out the confounding effects of caffeine. The meta-analysis suggested that green tea consumption had a favorable effect on decrease of BP.

Show MeSH
Related in: MedlinePlus