RESUMO
BACKGROUND: High doses of vitamin E have been shown to decrease lipid peroxidation in persons under oxidative stress. At present, the data are insufficient to predict whether lower doses offer the same benefit in healthy persons. OBJECTIVE: We studied the effect of moderate doses of a combination of vitamin E and carotenoids, incorporated into a food product, on markers of antioxidant status and lipid peroxidation in healthy persons. DESIGN: One hundred five healthy adults were randomly, evenly assigned in this double-blind, placebo-controlled, parallel, 11-wk intervention study. After a 2-wk stabilization period during which the subjects consumed a commercial unfortified spread, the subjects consumed 25 g/d of spread containing 43 mg alpha-tocopherol equivalents (alpha-TE; 2-3 fold the US dietary reference intake) and 0.45 mg carotenoids (spread A), 111 mg alpha-TE and 1.24 mg carotenoids (spread B), or 1.3 mg RRR-alpha-tocopherol without carotenoids (spread C). RESULTS: In subjects consuming spread A, plasma alpha-tocopherol concentrations increased 31% to 32 micromol/L, with small but significant increases in concentrations of alpha-carotene and lutein. This resulted in LDL with significantly higher total antioxidant capacity (17%) and an increased resistance to oxidation, as determined by lag time (18%). These improvements were dose dependent: larger increases in these variables were observed in subjects consuming spread B. Furthermore, consumption of spread B significantly reduced concentrations of the plasma lipid peroxidation biomarker F(2 alpha)-isoprostane (15%). CONCLUSION: The consumption of food products containing moderate amounts of vitamin E and carotenoids can lead to measurable and significant improvements in antioxidant status and biomarkers of oxidative stress in healthy persons.
