Effects of vitamin C supplementation in human volunteers with a
range of cholesterol levels on biomarkers of oxygen radical-generated
damage*
D. Anderson**, B. J. Phillips, Tian-Wei Yu, A. J. Edwards, R. Ayesh,
and K. R. Butterworth
TNO BIBRA International, Ltd., Woodmansterne Road,
Carshalton, Surrey SM5 4DS, UK
Abstract:. Twenty-four men and 24 women, all nonsmoking,
and maintaining normal dietary habits were assigned to 3 groups of 16.
Each group comprising 4 males with "low" cholesterol levels
(<6 mmol/L) matched for age and build with 4 males with "high"
cholesterol levels (>6 mmol/L) and 8 similarly matched females.
A three-treatment, three-treatment period, cross-over design was adopted.
The three treatments were placebo, 60 mg vitamin C/day (the recommended
daily allowance) and 6 g vitamin C/day for 14 days with 6 weeks
between treatments. Blood samples were taken at the end of each treatment
period. Vitamin C supplementation significantly increased plasma vitamin
C concentrations and total antioxidant capacity, but did not affect
cholesterol status or plasma ras p21 protein levels. There was
a nonsignificant dose-related decrease in plasma lipid peroxidation
breakdown products. DNA damage, measured in lymphocytes by the Comet
assay and chromosome aberration test, was not increased after vitamin
C supplementation. Sensitivity to hydrogen peroxide (in the Comet assay)
was also unaffected, but sensitivity to chromosome aberration induced
by bleomycin was increased by supplementation. A significant gender
difference was found in plasma vitamin C levels, antioxidant capacity,
and number of chromosome aberrations. Results were independent of low
and high cholesterol status.
*Lectures presented
at the 4th Congress of Toxicology in Developing Countries (4th CTOX-DC),
Antalya, Turkey, 6-10 November 1999
**Corresponding author
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