The current study aimed to investigate the influence of tart cherry and blueberry juices on cardiometabolic and other health indices following a 20-day supplementation period. Forty-five adults were randomly assigned to receive tart cherry, blueberry, or a placebo, of which they drank 60 mL per day for 20 days. The primary outcome, which was systolic blood pressure, and secondary measures, including anthropometric, energy expenditure, substrate oxidation, hematological, diastolic blood pressure/resting heart rate, psychological wellbeing, and sleep efficacy, were measured before and after the intervention. There were no statistically significant differences (p > 0.05) for systolic blood pressure; however, total and LDL cholesterol were significantly improved with blueberry intake (pre: total cholesterol = 4.36 mmol/L and LDL cholesterol = 2.71 mmol/L; post: total cholesterol = 3.79 mmol/L and LDL cholesterol = 2.23 mmol/L) compared to placebo (pre: total cholesterol = 4.01 mmol/L and LDL cholesterol = 2.45 mmol/L; post: total cholesterol = 4.34 mmol/L and LDL cholesterol = 2.67 mmol/L). Furthermore, psychological wellbeing indices measured using the Beck Depression Inventory, State Trait Anxiety Inventory, and COOP WONCA improved statistically in the blueberry arm compared to placebo. Given the clear association between lipid concentrations and the risk of cardiovascular disease as well as the importance of psychological wellbeing to health-related quality of life, this investigation indicates that it could be an effective approach to assist in managing cardiometabolic disease.

Cardiometabolic disease is recognized as the predominant cause of global mortality and healthcare expenditure. Whilst pharmaceutical interventions are effective in the short term, their long-term efficacy remain equivocal and their associated side-effects are concerning. Owing to their high levels of anthocyanins, Montmorency tart cherries and blueberries have been cited as potentially important natural treatment/preventative modalities for cardiometabolic disease. This study proposed a randomized controlled trial, aims to test the effects of consumption of Montmorency tart cherry and blueberry juice on cardiometabolic outcomes compared to placebo. This 20-day, parallel, single-blind, randomized, placebo-controlled trial will recruit 45 individuals, who will be assigned to receive 60 mL per day of either Montmorency tart cherry juice, blueberry juice or a cherry/blueberry flavoured placebo. The primary study outcome is the between-group difference in systolic blood pressure from baseline to post-intervention. Secondary outcome measures will be between-group differences in anthropometric, energy expenditure and substrate oxidation (during rest and physical activity), haematological, blood pressure/resting heart rate, psychological wellbeing and sleep efficacy indices. Statistical analysis will be conducted on an intention-to-treat basis. This study has been granted ethical approval by the University of Central Lancashire, Health Research Ethics Committee (ref: HEALTH 0016) and formally registered as a trial. Dissemination of the study findings from this investigation will be through publication in a leading peer-reviewed journal.