Effects of Short-Term Continuous Montmorency Tart Cherry Juice Supplementation in Participants with Metabolic Syndrome
Purpose: Metabolic Syndrome (MetS) augments the incidence of cardiovascular disease by 2-fold and type II diabetes mellitus by 5-fold. Montmorency tart cherries are rich in phytochemicals shown to improve biomarkers related to cardio-metabolic health in humans. This study aimed to examine cardio-metabolic responses after 7 days Montmorency tart cherry juice (MTCJ) supplementation and also acute responses to a single-bolus, in humans with MetS. Methods: In a randomised, single-blind, placebo-controlled, crossover trial, twelve participants with MetS (50 ±10 years; 6M/6F), consumed MTCJ or placebo (PLA) for 7 days. Blood-based and functional cardio-metabolic biomarkers were measured pre- and post-supplementation, and acute responses measured pre-bolus and up to 5 hours post-bolus on the 7th day. Results: 24-hour ambulatory systolic (P = 0.016), diastolic (P = 0.009) blood pressure and mean arterial pressure (P = 0.041) were significantly lower after 7 days MTCJ supplementation compared to PLA. Glucose (P = 0.038), total cholesterol (P = 0.036), LDL (P = 0.023) concentrations, total cholesterol:HDL ratio (P = 0.004) and respiratory exchange ratio values (P = 0.009) were significantly lower after 6 days MTCJ consumption compared to PLA. Conclusions: This study revealed for the first time MTCJ to significantly improve 24-hour BP, fasting glucose, total cholesterol and total cholesterol:HDL ratio, and also lower resting respiratory exchange ratio compared to a control in any human population. Responses demonstrated clinically relevant improvements on aspects of cardio-metabolic function, emphasising the potential efficacy of MTCJ in preventing further cardio-metabolic dysregulation in an ‘at risk’ population. Registered at clinicaltrials.gov (NCT03619941).