Effect of supplementation of smoking men with plain or slow release ascorbic acid on lipoprotein oxidation.
OBJECTIVE
To study the effects of two month ascorbic acid supplementation on in vitro lipoprotein oxidation resistance and on in vivo lipid peroxidation, and to compare the absorption of two ascorbic acid preparations.


METHODS
Randomized, single blinded and placebo-controlled clinical trial.


METHODS
Men, aged 36-65 y, smoking 11-40 cigarettes daily.


METHODS
Sixty-two subjects were recruited by newspaper advertisements and randomized. Fifty-nine subjects completed the study.


METHODS
Subjects were randomized into three groups to receive 250 mg BID of plain or slow release ascorbic acid tablets or placebo daily for two months. In the pharmacokinetic part of the study, the absorption of the ascorbic acid preparations was followed for 12 h.


METHODS
Plasma malondialdehyde (MDA) concentration and the oxidation resistance of VLDL + LDL. For the pharmacokinetic study, the area under the plasma concentration curve (AUC) of ascorbic acid.


RESULTS
Plasma reduced ascorbic acid increased by 32% in the plain ascorbate group and by 54% in the slow release group during a two month supplementation. Plasma MDA increased in the plain ascorbic acid group compared with placebo group (P < 0.05), but there were no significant differences in the changes in lipoprotein oxidation reactions induced by copper or by hemin and H2O2. Plasma reduced and total ascorbic acid AUC values were significantly higher in both plain and slow release ascorbate groups compared with placebo group.


CONCLUSIONS
Oral supplementation of 500 mg of ascorbic acid daily for two months alone without any other antioxidant does not appear to have protective effect on either in vitro lipoprotein oxidation resistance or in vivo lipid peroxidation in smoking men, but might even promote the formation of MDA.
Nyyssönen
K
K
Research Institute of Public Health, University of Kuopio, Finland.
Poulsen
H E
HE
Hayn
M
M
Agerbo
P
P
Porkkala-Sarataho
E
E
Kaikkonen
J
J
Salonen
R
R
Salonen
J T
JT
D000328:Adult; D000368:Aged; D000975:Antioxidants / Q000378:metabolism; D019540:Area Under Curve; D001205:Ascorbic Acid / Q000493:pharmacokinetics* / Q000494:pharmacology; D002851:Chromatography, High Pressure Liquid; D003692:Delayed-Action Preparations; D006801:Humans; D007408:Intestinal Absorption; D015227:Lipid Peroxidation / Q000187:drug effects; D008074:Lipoproteins / Q000187:drug effects / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000097:blood; D008297:Male; D008875:Middle Aged; D016037:Single-Blind Method; D012907:Smoking / Q000378:metabolism*
D000975:Antioxidants; D003692:Delayed-Action Preparations; D008074:Lipoproteins; D008077:Lipoproteins, LDL; D001205:Ascorbic Acid