09.09.13
Nutraceutical: Green Tea
Indication: Blood Glucose/Insulin Sensitivity
Source: American Journal of Nutrition August 2013
Research: According to this study abstract, results of research investigating the effect of green tea on glucose control and insulin sensitivity in humans is inconsistent. Researchers aimed to evaluate quantitatively the effect of green tea on glucose control and insulin sensitivity. They performed a strategic literature search of PubMed, EMBASE and the Cochrane Library (updated to January 2013) for randomized controlled trials that evaluated the effects of green tea and green tea extract on glucose control and insulin sensitivity. Study quality was assessed by using the Jadad scale. Weighted mean differences were calculated for net changes in glycemic measures by using fixed-effects or random-effects models. They conducted pre-specified subgroup and sensitivity analyses to explore potential heterogeneity. Meta-regression analyses were conducted to investigate dose effects of green tea on fasting glucose and insulin concentrations.
Results: Seventeen trials comprising a total of 1,133 subjects were included in the meta-analysis. Green tea consumption significantly reduced the fasting glucose and hemoglobin A1c (Hb A1c) concentrations by −0.09 mmol/L (95% CI: −0.15, −0.03 mmol/L; P < 0.01) and −0.30% (95% CI: −0.37, −0.22%; P < 0.01), respectively. Further stratified analyses from high Jadad score studies showed that green tea significantly reduced fasting insulin concentrations (−1.16 μIU/mL; 95%CI: −1.91, −0.40 μIU/mL; P = 0.03). This meta-analysis suggested that green tea had favorable effects (i.e., decreased fasting glucose and Hb A1c concentrations). Subgroup analyses showed a significant reduction in fasting insulin concentrations in trials with high Jadad scores, researchers concluded.
Indication: Blood Glucose/Insulin Sensitivity
Source: American Journal of Nutrition August 2013
Research: According to this study abstract, results of research investigating the effect of green tea on glucose control and insulin sensitivity in humans is inconsistent. Researchers aimed to evaluate quantitatively the effect of green tea on glucose control and insulin sensitivity. They performed a strategic literature search of PubMed, EMBASE and the Cochrane Library (updated to January 2013) for randomized controlled trials that evaluated the effects of green tea and green tea extract on glucose control and insulin sensitivity. Study quality was assessed by using the Jadad scale. Weighted mean differences were calculated for net changes in glycemic measures by using fixed-effects or random-effects models. They conducted pre-specified subgroup and sensitivity analyses to explore potential heterogeneity. Meta-regression analyses were conducted to investigate dose effects of green tea on fasting glucose and insulin concentrations.
Results: Seventeen trials comprising a total of 1,133 subjects were included in the meta-analysis. Green tea consumption significantly reduced the fasting glucose and hemoglobin A1c (Hb A1c) concentrations by −0.09 mmol/L (95% CI: −0.15, −0.03 mmol/L; P < 0.01) and −0.30% (95% CI: −0.37, −0.22%; P < 0.01), respectively. Further stratified analyses from high Jadad score studies showed that green tea significantly reduced fasting insulin concentrations (−1.16 μIU/mL; 95%CI: −1.91, −0.40 μIU/mL; P = 0.03). This meta-analysis suggested that green tea had favorable effects (i.e., decreased fasting glucose and Hb A1c concentrations). Subgroup analyses showed a significant reduction in fasting insulin concentrations in trials with high Jadad scores, researchers concluded.