Impact of green tea on the deleterious cardiometabolic effects of 7‐days unhealthy lifestyle in young healthy males

PURPOSE: The aim of this study was to examine if catechin‐rich green tea abrogates the negative effects of 7‐days of physical inactivity and excessive calorie‐intake on insulin homeostasis and peripheral vascular function. METHODS: Using a randomized, double‐blind, crossover design, twelve healthy men (29 ± 6 yrs) underwent 7‐days unhealthy lifestyle (UL), including physical inactivity (−50% steps/day) and overfeeding (+50% kcal/day). This was combined with green tea consumption (UL‐tea; 3 doses/day) or placebo (UL‐placebo). Before and after each intervention, we examined postprandial blood glucose and insulin (3‐h after a 1,202 kcal meal) and upper and lower limb vascular function (flow‐mediated dilation (FMD%)) and carotid artery reactivity (CAR%). RESULTS: UL‐placebo increased postprandial glucose and insulin, while UL‐tea decreased postprandial glucose and insulin (Time*Intervention interaction effects: both p < 0.05). UL‐placebo decreased CAR% and femoral FMD%, while UL‐tea prevented these effects (Time*Intervention interaction effects of p < 0.04 and p < 0.001, respectively). There was no main effect of Time or Time*Intervention interaction (both p > 0.05) for brachial FMD%. CONCLUSION: Seven days of physical inactivity and overfeeding impair insulin homeostasis and vascular function. These effects were mitigated by a daily intake of catechin‐rich green tea.