The Effect of Tea on Vascular Function and Insulin Sensitivity

Can Tea Prevent Impairments in Vascular Function and Insulin Sensitivity Induced by 7-days Physical Inactivity and Overfeeding in Healthy Men

The aim of this research is to explore changes in peripheral/cerebrovascular function and insulin sensitivity after a 7-day combination of physical activity reduction (-50% steps per day) and overfeeding (+50% kcal per day, comprising 65% fat) in healthy male volunteers, and examine whether daily intake of tea can prevent such changes.

The aim of this study is to explore the impact of a 7-day 'unhealthy' lifestyle that combines physical activity reduction (-50% steps per day) and overfeeding (+50% kcal per day, comprising 65% fat) on peripheral (conduit artery and skin microvessels) and cerebrovascular function and insulin sensitivity in healthy male participants. Moreover, the investigators will explore whether the detrimental impact of this lifestyle can be mitigated by daily tea consumption (equivalent to 6 cups/day). To explore this hypothesis, the investigators will perform measurements of these parameters before and after 7-days of reduced physical activity and overfeeding, with and without the combination of daily tea ingestion.

Inclusion Criteria:

• Aged 18-55 years
• Male
• Habitually active (>8,000 steps/day)
• Healthy

Exclusion Criteria:

• Smokers
• Medical history of cardiovascular/metabolic disease
• Family history of cardiovascular disease (first degree relatives)
• On medication known to influence the cardiovascular system
• BMI of <18 or >30 kg/m2
• Known food allergies or special dietary requirements
• Vaccination (<1 week) due to induced systemic inflammatory reaction