LACK OF EFFECT OF CHRONIC ADMINISTRATION OF ORAL BETA-CAROTENE ON SERUM-CHOLESTEROL AND TRIGLYCERIDE CONCENTRATIONS

Previous studies suggest that chronic oral administration of retinol and other retinoids causes elevation of plasma triglyceride concentrations. The effects of chronic oral administration of beta-carotene, a carotenoid partially metabolized to retinol, on plasma lipid concentrations have not been well studied; therefore, we studied 61 subjects over 12 mo while they were enrolled in a skin-cancer-prevention study in which patients were randomly assigned to receive either placebo (n = 30) or 50 mg beta-carotene/d orally (n = 31). At study entry and 1 y later, fasting blood samples were obtained for measurement of triglycerides, total cholesterol, HDL cholesterol, retinol, and beta-carotene. Retinol concentrations changed minimally in both groups; beta-carotene concentration increased an average of 12.1 +/- 47 nmol/L in the placebo group and 4279 +/- 657 nmol/L in the active-treatment group. Both groups experienced similar small increases in triglyceride and total cholesterol concentrations and small decreases in HDL cholesterol. Daily oral administration of 50 mg beta-carotene/d did not affect plasma lipid concentrations.