Introduction: Lycopene is a potent antioxidant and carotenoid in the ‘Mediterranean diet’. Plasma and adipose lycopene concentrations have previously been inversely correlated with cardiovascular disease (CVD) risk. We hypothesised that a standardised preparation of lycopene would improve endothelial function.

Methods: 36 healthy volunteers (HV) and 36 stable CVD patients on statins were randomised unequally (2:1) to either 7mg lycopene or placebo daily for 2 months (NCT01100385). Forearm blood flow responses to intra-arterial infusions of acetylcholine, (endothelium-dependent vasodilatation,EDV); sodium nitroprusside (endothelium-independent vasodilatation.EIDV); and N^G-monomethyl-L-arginine (measuring basal nitric oxide,NO) were measured using venous plethysmography.

Results: At baseline, both groups were similar in age, BP and hs-CRP but the CVD group had a lower LDL (2.4 ±0.6 vs. 3.6 ±0.9mmol/L, P<0.001). The CVD group had impaired EDV to ACh compared with HV (30% lower; 95%CI: −45, −10, P=0.008). Lycopene improved EDV in CVD patients by 53% (95%CI: +9, +93, P=0.03 vs. placebo) independent of changes in EIDV or basal NO. Lycopene did not change EIDV, EDV or basal NO in HV. Home blood pressure, LDL, HDL and hs-CRP levels were unchanged in both groups. A post-hoc analysis demonstrated that lycopene treatment improved EDV in CVD patients towards HV levels at baseline (3% lower; 95% CI: −30, +30, P=0.85), suggesting normalization of vascular function.

Conclusion: Lycopene supplementation improves endothelial function in CVD patients but not HV, and may require further investigation in larger outcome studies.