Combination oral antioxidant supplementation reduces blood pressure

1. Hypertension affects 30% of adults and low intakes of antioxidants have been associated with increased risk of hypertension and cardiovascular disease, To investigate the effect of short-term high-dose antioxidant supplementation on blood pressure in hypertensive and normotensive outpatients, we undertook a randomized, double-blind, crossover design placebo-controlled study, 2. Forty subjects were recruited from medical outpatient clinics, of whom 38 completed the study, Twenty-one were attending for treatment of hypertension and 17 were normotensive, attending for minor gastrointestinal complaints, Subjects were randomly assigned to receive either 8 weeks placebo followed by 2 weeks washout then 8 weeks antioxidants or vice versa, The combination of antioxidants consisted of 200 mg of zinc sulphate, 500 mg of ascorbic acid, 600 mg of alpha-tocopherol (sodium succinate salt) and 30 mg of beta-carotene daily, 3. Systolic blood pressure fell at the end of the antioxidant phase compared with the placebo phase both in subjects receiving anti-hypertensive therapy (P<0.01) and those who were normotensive (P=0.067), Circulating levels of B-carotene and a-tocopherol increased in all subjects during supplementation (P<0.01) and urine nitrite increased in hypertensive patients (P<0.05), 4. Short-term oral high-dose combination antioxidant therapy reduces blood pressure, possibly via increased availability of nitric oxide, This study may have implications for the innovative use of antioxidants as an adjunct to anti-hypertensive therapy.