Green tea polyphenols attenuate resistance exercise-induced increase in proinflammatory cytokines in obese men

Green tea polyphenols have been suggested to exert antiinflammatory actions in in vivo and in vitro studies. The aim of this study was to investigate the effect of green tea extract (GTE) supplementation on pro-inflammatory cytokines during a single bout of resistance exercise (RE) in obese men. Participants were ten obese men who participated in a randomized, double-blind, placebocontrolled (PL) crossover study, administered 14-day GTE (500 mg/day) supplementation and PL with a 14-day washout period. After the supplementation periods, the participants performed the RE protocol, consisting of three sets of six exercises, to failure at 75% of one repetition maximum (1RM) and 2 min rest between sets. The serum samples were collected pre- and post-RE and analyzed for TNF-α, IL-1α, and IFN-γ. RE significantly increased TNF-α and IL-1α in obese men by 15% (p=0.043) and 18.71% (p=0.003) above the pre-RE values in the PL condition, respectively. However, GTE supplementation inhibited acute RE-induced increases in the TNF-α and IL-1α levels in obese men. Moreover, changes in the IFN-γ level during RE tended to be lower in GTE compared to the PL condition. Based on the findings, it can be concluded that 14-day GTE supplementation offers protection against RE-induced increases in pro-inflammatory cytokines in obese men. These immunomodulatory effects of GTE may be, in part, due to the anti-inflammatory properties of GTE in obese men that can be considered as a potential therapeutic factor to ameliorate obesity-associated inflammation.