Key result
Longer-term L-citrulline supplementation significantly improved brachial artery flow-mediated vasodilation by 0.9 percentage points compared to control.
Why the study?
l-Citrulline may improve non-invasive vascular function and cardiometabolic risk markers via increased l-arginine bioavailability and nitric oxide synthesis, but its longer-term and postprandial effects required meta-analytic evaluation.
Does L-citrulline supplementation or watermelon consumption improve vascular function and cardiometabolic risk markers in adults?
Meta-Analysis (n=576)
Does L-citrulline supplementation or watermelon consumption improve vascular function and cardiometabolic risk markers in adults?
Mean Difference: 0.9 (95% CI 0.7–1.1)
p-value: p=<0.001
Longer-term L-citrulline supplementation and watermelon consumption may improve vascular function markers such as FMD and PWV in adults, suggesting a potential cardiovascular benefit.
L-citrulline may support endothelial health in adults; extends acute data to longer-term supplementation.
Abstract l -Citrulline may improve non-invasive vascular function and cardiometabolic risk markers through increases in l -arginine bioavailability and nitric oxide synthesis. A meta-analysis of randomised controlled trials (RCT) was performed to examine longer-term and postprandial effects of l -citrulline supplementation and watermelon consumption on these markers for CVD in adults. Summary estimates of weighted mean differences in vascular function and cardiometabolic risk markers with accompanying 95 % CI were calculated using random or fixed-effect meta-analyses. Seventeen RCT were included involving an l -citrulline intervention, of which six studied postprandial and twelve longer-term effects. Five studies investigated longer-term effects of watermelon consumption and five assessed effects during the postprandial phase. Longer-term l -citrulline supplementation improved brachial artery flow-mediated vasodilation (FMD) by 0·9 %-point (95 % CI 0·7, 1·1, P < 0·001). Longer-term watermelon consumption improved pulse wave velocity by 0·9 m/s (95 % CI 0·1, 1·5, P < 0·001), while effects on FMD were not studied. No postprandial effects on vascular function markers were found. Postprandial glucose concentrations decreased by 0·6 mmol/l (95 % CI 0·4, 0·7, P < 0·001) following watermelon consumption, but no other longer-term or postprandial effects were observed on cardiometabolic risk markers. To conclude, longer-term l -citrulline supplementation and watermelon consumption may improve vascular function, suggesting a potential mechanism by which increased l -citrulline intake beneficially affects cardiovascular health outcomes in adults. No effects on postprandial vascular function markers were found, while more research is needed to investigate the effects of l -citrulline and watermelon on risk markers related to cardiometabolic health.
No takes yet. Share an insight, caveat, or question.
A 2021 study conducted a meta-analysis in Cardiometabolic risk and vascular function in adults (n=576). L-citrulline supplementation and watermelon consumption vs. Placebo or control was evaluated on Brachial artery flow-mediated vasodilation (FMD) (WMD 0.9 %-point, 95% CI 0.7, 1.1, p=<0.001). Longer-term L-citrulline supplementation significantly improved brachial artery flow-mediated vasodilation by 0.9 percentage points compared to control.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: