ANTIOXIDANT NUTRIENT SUPPLEMENTATION REDUCES THE SUSCEPTIBILITY OF LOW-DENSITY-LIPOPROTEIN TO OXIDATION IN PATIENTS WITH CORONARY-ARTERY DISEASE

Objectives, This study sought to determine the effect of antioxidant s upplementation on the susceptibility of low density lipoprotein (LDL) to oxidation in patients,vith established cardiovascular disease (CVD) , Background. Data are inconsistent regarding the role of anti oxidant nutrients in the prevention of CVD. Methods. The study design was a 1 2 week, double blind, placebo controlled clinical trial, Patients with CVD (n = 45) were randomized to 1) placebo control; 2) 400 IU of vita min E, 500 mg of vitamin C, 12 mg of beta-carotene (mid-dose); or 3) 8 00 IU of vitamin E, 1,000 mg of vitamin C, 24 mg of beta-carotene (hig h dose) daily. Reduced susceptibility of LDL to oxidation was estimate d by an increase in lag phase (minutes), Baseline and 6- and 12-week m easurements of lipoproteins and lag phase were obtained, Plasma levels of antioxidants were measured at baseline and 12 weeks. Results. Conc entrations of alpha-tocopherol, vitamin C and beta-carotene significan tly increased in the mid- and high dose groups during the trial, Lag p hase significantly increased from baseline (190.1 +/- 63.8 min [mean /- SD]) to 12 weeks (391.1 +/- 153.0 min) in the high dose group (p < 0.01). A nonsignificant increase in lag phase in the mid dose group wa s observed during the same time interval. A dose response,vas found fo r mean percent change from baseline to 12 weeks for lag phase for the placebo, mid- and high dose groups (p = 0.004 for trend), Conclusions. A high dose combination of antioxidant nutrients reduces the suscepti bility of LDL to oxidation in patients with CVD and may be useful in s econdary prevention. (C) 1997 by the American College of Cardiology.