These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effects of beta-carotene supplementation on free radical mechanism in healthy adult subjects.
    Author: Elmadfa I, Rust P, Majchrzak D, Wagner KH, Genser D, Lettner R, Pinter M.
    Journal: Int J Vitam Nutr Res; 2004 Mar; 74(2):147-52. PubMed ID: 15255452.
    Abstract:
    AIM: The objective of this study was to examine whether increasing doses of beta-carotene supplements have effects on biological markers of lipid peroxidation in healthy volunteers. SUBJECTS AND METHODS: Forty-two healthy subjects were supplemented with 5 mg, 10 mg, 20 mg or 40 mg beta-carotene/day, respectively for five weeks. Plasma beta-carotene and tocopherol levels, malondialdehyde-thiobarbituric reactive substances (MDA-TBARS), and conjugated dienes were determined using high-performance liquid chromatography (HPLC). Concentrations of ascorbic acid, uric acid, and the total antioxidative capacity (TAC) in plasma were measured photometrically. RESULTS: Plasma beta-carotene levels increased significantly according to the intervention dose (p < 0.001), and concentrations of tocopherol equivalents and ascorbic acid were within the physiological range except in the 5 mg intervention group where a significant decrease of vitamin C was assessed (p < 0.05). Uric acid in plasma decreased significantly in all groups (p < 0.05) up to the end of investigation, but was within the normal range. Trolox equivalent antioxidative capacity (TEAC) decreased significantly (p < 0.001) in all groups during supplementation. MDA-TBARS remained unchanged after five weeks except for the 40 mg beta-carotene substitution group, where a significant decrease was observed (p < 0.05). CONCLUSION: Beta-carotene supplementation of healthy subjects significantly increased plasma beta-carotene status without inducing adverse biological effects. Beta-carotene did not especially protect against oxidative stress, except for the 40 mg group. These data suggest that additional effects of beta-carotene supplementation on well-nourished, healthy subjects are limited.
    [Abstract] [Full Text] [Related] [New Search]