Introduction: Serum uric acid is linked to vascular nitric oxide activity and therefore can blunt endothelium-dependent vasodilation. Antioxidants may increase nitric oxide activity and endothelial function and this might result in decreased uric acid levels.

Aim: The objective was to investigate if supplementation with antioxidants has a beneficial effect on uric acid.

Method: 74 borderline hypertensive Caucasian men participated (aged 45–65 years) in a randomized double-blind, cross-over intervention trial receiving either an antioxidant cocktail (vitamin C, E and folic acid) or placebo. Cardiovascular parameters were recorded with the Finometer. The Complior SP was used to measure the carotid-radialis PWV.

Results: Folic acid (as an indicator of compliance to antioxidant intake) increased significantly with 30% (P=0.005) with no changes in the placebo group. Uric acid was lower after the antioxidant intervention (changed from 0.53 mmol/L to 0.49 mmol/L (p=0.007), with no change in the placebo group. No significant differences were found between the pre and post intervention values for blood pressure, total peripheral resistance and PWV for both interventions .

Significant correlations were found between uric acid and total cholesterol (placebo r=0.54: P< 0.001; antioxidant r=0.25: P=0.04).

Conclusion: With antioxidant intervention the lowered uric acid level point to a improvement in vascular function and oxidative stress. The weaker correlation between uric acid and cholesterol also points to improved vascular function since uric acid is strongly linked to cholesterol in vascular disease.