Triple-Tea (Tea Time Trial): Flavonoid-rich tea to improve cardiometabolic health and to enhance the effects of training in pre-diabetes.

Applications are invited for a PhD studentship to start in September 2018/January 2019. The studentship is based in the School of Sports Studies, Leisure and Nutrition (Faculty of Education, Health and Community) but will include close collaboration with the Research Institute for Sport and Exercise Sciences (Faculty of Science).

Prediabetes (i.e., insulin resistance) is increasingly prevalent, with an expected prevalence of 500 million people by 2030. Prediabetes has an annual conversion rate of 10% for type 2 diabetes, but is also associated with cardiovascular disease and abnormal lipoprotein subclasses. This emphasises the need for effective prevention strategies, focused on lifestyle modifications in diet and physical activity, which should be implemented as early in a person’s life as possible. Consumption of flavonoid-rich products (e.g. tea) lowers occurrence of cardiovascular events. Observational work found that tea may also reduce the risk for type 2 diabetes mellitus. To explore this link, we have previously assessed the direct impact of flavonoids on glucose homeostasis. We found that flavonoid-rich black tea improved postprandial glucose homeostasis in obese, insulin-resistant men. Moreover, we recently found that 7-days of an unhealthy lifestyle (i.e. +50% calorie-intake, -50% steps) impaired glucose homeostasis and vascular health, which was prevented by ingesting flavonoid-rich tea. This raises the question if (flavonoid-rich) green tea can improve cardiometabolic health in prediabetes.The metabolic benefits of flavonoids may relate to their ability to improve mitochondrial function and, therefore, enhance ergogenic effects. Moreover, recent work indicated that flavonoids increase post-exercise systemic fat oxidation and GLUT4-protein content. Based on these effects, we propose the novel concept that daily (flavonoid-rich) tea intake enhances the metabolic and cardiovascular effects of exercise training in prediabetes.

The project will examine the impact of 3-month daily intake of (flavonoid-rich) green tea on cardiometabolic health in pre-diabetic subjects (Aim 1), and explore if the ergogenic effects of green tea can enhance the effects of exercise training (Aim 2). This will maximise the benefits of lifestyle interventions in this vulnerable group of patients. We also anticipate additional hypothesis testing aiming to facilitate a larger randomised controlled trial.

Based on our previous work, we expect our double-blind RCT to show that green tea improves cardiometabolic health in pre-diabetes. Given its ergogenic effects, we predict green tea to enhance the health effects of exercise training.

We are seeking a highly motivated, pro-active individual with an interest in cardiometabolic health in pre-diabetes, nutrition and the benefits of exercise training. Excellent personal skills for interacting with research participants, excellent organisational skills to coordinate the contribution of two faculties and enthusiasm for quantitative research methods and advanced analysis procedures are essential for this project.