The Effect of Green Tea Extract on Expression of TNF-α After Resistance Exercise in Obese Men: Randomized, Double-Blind, Placebo-Controlled, Cross-Over Study

Green tea contains large amounts of polyphones antioxidants which has great impacts such as antioxidant activity, anti-inflammatory, inhibition adipogenesis and apoptosis of adipocytes. Therefore, in this study, effects of two weeks of green tea extract on the expression of TNF-α and the level of this pro-inflammatory factor after resistance exercise in obese individuals were study.
In a randomized, double-blind, placebo-controlled, cross-over study, eight obese men (BMI greater than kg.m-2 30) were recruited. The subjects did not have any regular physical activity prior to the study subjects were allocated in the green tea extract (two capsules of 500 mg per day) group and placebo (two capsules of 500 mg maltodextrin days) for 2 weeks.; following the 2 weeks, participants were subjected to sessions of resistance exercise with 75% of 1RM intensity. Blood samples were taken before (pre test) and immediately after (post test) the resistance exercise to measure gene expression and serum levels of TNF-α.
TNF-α mRNA expression was lowered a result of green tea extract consumption by 44% in pre test and 11% in post test compared with placebo, a percentage difference in gene expression were observed but these results were not statistically significant (p>0.05). Also, the concentrations of TNF-α in green tea consumption was lower in pre-test 16.86% (P=0.83) and the post-test 24.78% (P=0.05) compared to placebo.
Green tea extract supplements can prevent the increases in the pro-inflammatory marker of TNF-α after resistance exercise in obese men.