Effects of vitamin C and vitamin E on in vivo lipid peroxidation: results of a randomized controlled trial.
BACKGROUND
Lipid peroxidation may be important in the pathogenesis of atherosclerosis, particularly in its earliest stages. Evidence predominantly from in vitro studies suggests that antioxidant vitamins can prevent lipid peroxidation and that vitamin C and vitamin E have synergistic effects. However, in vivo evidence in support of these hypotheses is sparse.


OBJECTIVE
The objective was to determine the effects of vitamin C and vitamin E, alone or in combination, on in vivo lipid peroxidation.


METHODS
We conducted a placebo-controlled, 2 x 2 factorial trial of vitamin C (500 mg ascorbate/d) and vitamin E (400 IU RRR-alpha-tocopheryl acetate/d) supplementation in 184 nonsmokers. The mean duration of supplementation was 2 mo. The outcome measures were changes from baseline in urinary 8-iso-prostaglandin F(2alpha), urinary malondialdehyde + 4-hydroxyalkenals, and serum oxygen-radical absorbance capacity.


RESULTS
The within-group mean changes (and 95% CIs) in urinary 8-iso-prostaglandin F(2alpha) (pg/mg creatinine) were 9.0 (-125.1, 143.1), -150.0 (-275.4, -24.6), -141.3 (-230.5, -52.1), and -112.5 (-234.8, 9.8) in the placebo, vitamin C alone, vitamin E alone, and vitamins C + E groups, respectively. No synergistic effect of these 2 vitamins on urinary 8-iso-prostaglandin F(2alpha) was observed (P = 0.12). Neither vitamin had an effect on urinary malondialdehyde + 4-hydroxyalkenals. Vitamin C, but not vitamin E, increased serum oxygen-radical absorbance capacity (P = 0.01).


CONCLUSIONS
Supplementation with vitamin C or vitamin E alone reduced lipid peroxidation to a similar extent. Supplementation with a combination of vitamins C and E conferred no benefit beyond that of either vitamin alone.
Huang
Han-Yao
HY
Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore 21205-2223, USA. hyhuang@jhsph.edu
Appel
Lawrence J
LJ
Croft
Kevin D
KD
Miller
Edgar R
ER
Mori
Trevor A
TA
Puddey
Ian B
IB
D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000008:administration & dosage*; D001205:Ascorbic Acid / Q000008:administration & dosage*; D015237:Dinoprost / Q000031:analogs & derivatives*; D028441:F2-Isoprostanes / Q000652:urine; D005260:Female; D006801:Humans; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D008315:Malondialdehyde / Q000652:urine; D008875:Middle Aged; D010919:Placebos; D017382:Reactive Oxygen Species / Q000097:blood; D024505:Tocopherols; D016896:Treatment Outcome; D024502:alpha-Tocopherol / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000097:blood
D000975:Antioxidants; D028441:F2-Isoprostanes; D010919:Placebos; D017382:Reactive Oxygen Species; C075750:8-epi-prostaglandin F2alpha; D008315:Malondialdehyde; D015237:Dinoprost; D024502:alpha-Tocopherol; D001205:Ascorbic Acid; D024505:Tocopherols