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 cardiovas cular disease, To investigate the effect of short-term high-dose antio xidant supplementation on blood pressure in hypertensive and normotens ive outpatients, we undertook a randomized, double-blind, crossover de sign placebo-controlled study, 2. Forty subjects were recruited from m edical 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 random ly assigned to receive either 8 weeks placebo followed by 2 weeks wash out then 8 weeks antioxidants or vice versa, The combination of antiox idants 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-c arotene daily, 3. Systolic blood pressure fell at the end of the antio xidant phase compared with the placebo phase both in subjects receivin g 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 incr eased in hypertensive patients (P<0.05), 4. Short-term oral high-dose combination antioxidant therapy reduces blood pressure, possibly via i ncreased availability of nitric oxide, This study may have implication s for the innovative use of antioxidants as an adjunct to anti-hyperte nsive therapy.