Low dose of green tea catechins improves endothelial function and vascular smooth muscle cell reactivity in obese women

Abstract

BACKGROUND: The high prevalence of obesity in the world is associated with several health problems, with endothelial dysfunction figuring as a frequent feature. We investigated whether low dose consumption of green tea extract (catechins,< 200 mg/day) could modify endothelial function, lipid profile, fasting glucose and insulin, post load plasma glucose, inflammatory/oxidative stress biomarkers and blood pressure in obese women. METHODS: Sixteen obese women with body mass index (BMI) between 30 and 40 Kg/m2, mean age 38 [33-40] years, consumed 600 ml green tea (3 × 200 ml) per day, containing 153.3 mg of catechins and 72.5 mg of caffeine, during three months. Endothelial function was evaluated through venous occlusion plethysmography by increment of peak forearm blood flow (FBF), after 5 min ischemia, during the reactive hyperemia response/baseline FBF. Endothelium-independent vasodilation was analyzed through peak FBF after 0.4 mg sublingual nitroglycerin/baseline FBF. RESULTS: After 3 months, this consumption of green tea reduced BMI from 34.02 to 33.13, and diastolic blood pressure by 4 mmHg. The reactive hyperemia response/baseline FBF improved by 27%, and the endothelium-independent vasodilation by 12%. The blood biochemical profile, where all parameters were within the normal range, remained unaltered. CONCLUSIONS: A low dose of green tea ameliorated the endothelial dysfunction present in obesity, indicating that its consumption should be encouraged in these patients, because endothelial dysfunction is an early marker of atherosclerosis.