Data from a combined total of 1,133 subjects indicated that green tea consumption was associated with significantly lower blood sugar levels during fasting, and lower blood concentrations of hemoglobin A1c (HbA1c), a marker of long-term presence of excess glucose in the blood.
Subsequent analysis also showed that green tea consumption was associated with reduced fasting insulin levels.
“The current analyses showed slight inconsistencies in the effects of green tea on glycemic measures in the subgroup analyses,” wrote researchers from the Third Military Medical University in Chongqing, China.
“Green tea consumption significantly decreased fasting glucose concentrations only in studies that included subjects with risk of the metabolic syndrome. This suggested that the beneficial effect of green tea (ie, lowering fasting glucose concentrations) might be more pronounced in subjects with factors that increase their risk of the metabolic syndrome.”