Effects of green tea extract on oxidative stress and renal function in diabetic individuals: A randomized, double-blinded, controlled trial

Abstract

The effects of green tea on oxidative stress and renal function in diabetes remains inconclusive. This study aimed to evaluate the effect of green tea extract on oxidative stress and renal function in diabetic individuals. A randomized, double-blinded, controlled clinical trial was developed with 60 diabetic individuals. Patients were assigned to receive green tea extract (two capsules/day, containing 560 mg of polyphenols/each) or cellulose (two capsules/day) for 20 weeks. Glycaemic control and renal function markers, antioxidant enzymes and total antioxidant capacity were analysed. No difference was observed in glycaemic control, renal function, and oxidative stress, except for superoxide dismutase. After 20 weeks, green tea extract maintained this enzyme activity, whereas an expressive reduction in the placebo group was noted (p = 0.014). Green tea extract prevented the reduction of superoxide dismutase activity; however, it was not associated with an improvement in total antioxidant capacity, glycaemic control markers or renal function.

Keywords

• Diabetes Mellitus
• Camellia sinensis
• Oxidative stress
• Albuminuria