Lipoprotein carotenoid profiles and the susceptibility of low density lipoprotein to oxidative modification in healthy elderly volunteers
Sommaire de l'article
To determine antioxidant levels in plasma, low density lipoprotein (LDL) and high density Lipoprotein (HDL) before and after supplementation with a carotene mixture or lycopene; to examine the interrelationships between carotenoids and tocopherols in plasma, LDL and HDL under normal dietary conditions and after supplementation with carotene or lycopene; and to investigate whether supplementation with a carotene mixture or lycopene could enhance the ability of LDL to withstand oxidative stress in vitro, in a group of healthy elderly people aged greater than or equal to 65 y.
Randomized placebo controlled double blind study.
Free living urban adults in ireland.Subjects: Fifty-one volunteers aged greater than or equal to 65 y.Interventions: Volunteers were each provided with capsules providing either 13.3 mg lycopene, or 11.9 mg carotene or placebo for 12 weeks.
Both absolute and cholesterol standardized plasma carotenoid concentrations correlated strongly with LDL and HDL concentrations of carotenoids before and after supplementation with carotene or lycopene. Supplementation with a carotene mixture or lycopene had no effect on oxidative modification of LDL in vitro despite significant increases in plasma and LDL concentrations of lycopene, alpha-carotene and beta-carotene.
The results of this study suggest that, in unsupplemented individuals, plasma can act as a biomarker of carotenoid and gamma-tocopherol concentrations in both LDL and HDL. Supplementation with carotenes or lycopene do not reduce or delay oxidation of LDL. These results support the assumption that carotenoids, such as beta-carotene and lycopene, may show protective effects because they are good markers of fruit and vegetable intake.