Effect of beta-carotene supplementation on the concentrations and distribution of carotenoids, vitamin E, vitamin A, and cholesterol in plasma lipoprotein and non-lipoprotein fractions in healthy older women

Abstract

Objective: We studied the effect of beta-carotene supplementation on the concentrations and distribution in plasma lipoprotein and non-lipoprotein fractions of carotenoids, alpha-tocopherol, retinol, and cholesterol.

Methods: Ten women ingested either 90 mg of beta-carotene or placebo daily for 3 weeks while residing in their homes and eating their usual meals. Carotenoids (beta-carotene, lycopene, lutein/zeaxanthin), retinol, alpha-tocopherol, and cholesterol were measured in plasma lipoprotein and non-lipoprotein fractions before and after treatment.

Results: In the beta-carotene-supplemented group, total plasma beta-carotene increased 14-fold from 0.48 +/- 0.13 to 6.83 +/- 2.12 mumol/L (p = 0.04). Although the greatest increase in beta-carotene was in low-density-lipoproteins (LDL), the magnitude of increase was similar in LDL, high-density-lipoproteins (HDL), and very-low-density-lipoproteins (VLDL). Thus, the relative distribution of beta-carotene in lipoproteins was unchanged: approximately 71% was in LDL, approximately 15% in HDL and approximately 12% in VLDL, before and after beta-carotene supplementation. There were no changes in amounts and distribution in lipoproteins of the other carotenoids, alpha-tocopherol, and cholesterol. There was no change in the amount of retinol in lipoprotein-deficient plasma. There were no changes in total plasma triglycerides. Significant positive correlations were found between LDL- or VLDL-cholesterol and alpha-tocopherol in LDL or VLDL, respectively; between LDL- or VLDL-cholesterol and lutein/zeaxanthin in LDL or VLDL, respectively; and between HDL-cholesterol and beta-carotene in HDL.

Conclusions: beta-Carotene supplementation (90 mg/day for 3 weeks) in healthy older women results in an enrichment of all plasma lipoprotein fractions with beta-carotene, but does not alter the relative distribution of beta-carotene in lipoproteins. beta-Carotene supplementation has no effect on the amounts and relative distribution of lycopene, lutein/zeaxanthin, and alpha-tocopherol in lipoproteins, or of retinol in the non-lipoprotein fraction of plasma. Short-term beta-carotene supplementation has no effect on the concentrations of plasma total triglycerides, total cholesterol, HDL-, LDL-, and VLDL-cholesterol.