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Green tea extract outperforms metformin in lipid profile and glycaemic control in overweight women: A double-blind, placebo-controlled, randomized trial

Alves Ferreira, Monallisa, Oliveira Gomes, Anna Paula, Guimarães de Moraes, Ana Paula, Ferreira Stringhini, Maria Luiza, Mota, João Felipe, Siqueira Guedes Coelho, Alexandre, Borges Botelho, Patrícia
Clinical nutrition ESPEN 2017 v.22 pp. 1-6
adjuvants, anthropometric measurements, blood sampling, body composition, cellulose, cholesterol, glucose, glycemic control, green tea, lipid composition, metformin, noninsulin-dependent diabetes mellitus, obesity, risk factors, women
Both green tea and metformin are used as adjuvants to treat and prevent complications associated with obesity; however, studies comparing their action and interaction in non-diabetic overweight women have not been reported. Thus, the current study evaluated the effects of green tea extract and metformin, both individually and in combination, on type 2 diabetes risk factors in non-diabetic overweight women.A total of 120 overweight women were randomly assigned in a double-blind manner to 1 of 4 groups, as follows: control (n = 29; 1 g of cellulose), green tea (n = 32; 1 g of dry green tea extract), metformin (n = 28; 1 g of metformin), and green tea + metformin (n = 31; 1 g of dry green tea extract + 1 g of metformin). Each group took the indicated capsules daily for 12 weeks. Anthropometric measurements, body composition, and fasting blood samples were evaluated.Although no significant interactions were observed in glycaemic control (p = 0.07), green tea in the absence of metformin reduced fasting glucose (−4.428 ± 2.00; p = 0.031), but when combined the lowering effect was nullified. In contrast, metformin increased HbA1c concentration (0.048 ± 0.189%; p = 0.017) and also reduced body weight (−1.318 ± 0.366 kg; p = 0.034) and LM (lean mass) (−1.249 ± 0.310; p = 0.009). Regarding lipid parameters, green tea significantly reduced total cholesterol and LDL-c.Green tea was superior to metformin in improving glycaemic control and lipid profile in non-diabetic overweight women and, therefore, green tea extract is a promising alternative for reducing type 2 diabetes risk in overweight women.