Antioxidant treatment with ascorbic acid was initially shown to lower blood pressure in a limited number of patients with hypertension394,395. However, larger studies have not found a clear beneficial effect of antioxidant vitamins on the development or control of blood pressure396,397. The combination of ascorbic acid and polyphenols actually resulted in a higher blood pressure variation327. Therefore, there is insufficient evidence to support the use of dietary supplements in the primary prevention of cardiovascular diseases388. However, the period of treatment and doses398 could be crucial in the beneficial or deleterious effects of antioxidant therapy. What is evident from these published data is that the effect of the ROS on the cardiovascular system is more complex than expected and innovative approaches must be formulated to resolve these discrepant results.