Supplementation with vitamin E but not with vitamin C lowers lipid peroxidation in vivo in mildly hypercholesterolemic men.
Although the use of vitamin E supplements has been associated with a reduction in coronary events, assumed to be due to lowered lipid peroxidation, there are no previous long-term clinical trials into the effects of vitamin C or E supplementation on lipid peroxidation in vivo. Here, we have studied the long-term effects of vitamins C and E on plasma F2-isoprostanes, a widely used marker of lipid peroxidation in vivo. As a study cohort, a subset of the "Antioxidant Supplementation in Atherosclerosis Prevention" (ASAP) study was used. ASAP is a double-masked placebo-controlled randomized clinical trial to study the long-term effect of vitamin C (500 mg of slow release ascorbate daily), vitamin E (200 mg of D-alpha-tocopheryl acetate daily), both vitamins (CellaVie), or placebo on lipid peroxidation, atherosclerotic progression, blood pressure and myocardial infarction (n = 520 at baseline). Lipid peroxidation measurements were carried out in 100 consecutive men at entry and repeated at 12 months. The plasma F2-isoprostane concentration was lowered by 17.3% (95% CI 3.9-30.8%) in the vitamin E group (p = 0.006 for the change, as compared with the placebo group). On the contrary, vitamin C had no significant effect on plasma F2-isoprostanes as compared with the placebo group. There was also no interaction in the effect between these vitamins. In conclusion, long-term oral supplementation of clinically healthy, but hypercholesterolemic men, who have normal vitamin C and E levels with a reasonable dose of vitamin E lowers lipid peroxidation in vivo, but a relatively high dose of vitamin C does not. This observation may provide a mechanism for the observed ability of vitamin E supplements to prevent atherosclerosis.
Kaikkonen
J
J
Oy Jurilab Ltd., Kuopio, Finland.
Porkkala-Sarataho
E
E
Morrow
J D
JD
Roberts
L J
LJ
Nyyssönen
K
K
Salonen
R
R
Tuomainen
T P
TP
Ristonmaa
U
U
Poulsen
H E
HE
Salonen
J T
JT
D000368:Aged; D000704:Analysis of Variance; D001205:Ascorbic Acid / Q000097:blood / Q000494:pharmacology*; D019587:Dietary Supplements; D028441:F2-Isoprostanes / Q000097:blood; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D006937:Hypercholesterolemia / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D012907:Smoking; D014810:Vitamin E / Q000097:blood / Q000494:pharmacology*
D028441:F2-Isoprostanes; D014810:Vitamin E; D001205:Ascorbic Acid