{alpha}-Tocopherol disappearance is faster in cigarette smokers and is inversely related to their ascorbic acid status.
BACKGROUND
Cigarette smokers have enhanced oxidative stress from cigarette smoke exposure and from their increased inflammatory responses.


OBJECTIVE
The objective of this study was to determine whether cigarette smoking increases plasma alpha-tocopherol disappearance in otherwise healthy humans.


METHODS
Smokers and nonsmokers (n = 10/group) were supplemented with deuterium-labeled alpha-tocopheryl acetates (75 mg each of d(3)-RRR-alpha-tocopheryl acetate and d(6)-all-rac-alpha-tocopherols acetate) for 6 evenings (days -6 to -1). Plasma alpha-tocopherols, ascorbic acid, uric acid, and F(2alpha)-isoprostanes were measured in blood samples collected on days -6 through 17. The urinary alpha-tocopherol metabolite, alpha-carboxy-ethyl-hydroxy-chroman (alpha-CEHC), was measured on days -6, 0, and 17 in 24-h urine samples.


RESULTS
F(2alpha)-isoprostanes were, on average, approximately 40% higher in smokers than in nonsmokers. On day 0, plasma labeled and unlabeled alpha-tocopherol concentrations were not significantly different between groups. Smoking resulted in faster fractional disappearance of plasma alpha-tocopherol (0.215 +/- 0.011 compared with 0.191 +/- 0.009 pools/d; P < 0.05). Fractional disappearance rates of alpha-tocopherol correlated with plasma ascorbic acid concentrations in smokers (P = 0.021) but not in nonsmokers despite plasma ascorbic acid concentrations that were not significantly different between groups. By day 17, cigarette smoking resulted in lower plasma alpha-tocopherol concentrations and urinary excretion of labeled and unlabeled alpha-CEHC (P < 0.05).


CONCLUSIONS
Cigarette smoking increased alpha-tocopherol disappearance. Greater rates of alpha-tocopherol disappearance in smokers appear to be related to increased oxidative stress accompanied by lower plasma ascorbic acid concentrations. Thus, smokers have an increased requirement for both alpha-tocopherol and ascorbic acid.
Bruno
Richard S
RS
Department of Human Nutrition, The Ohio State University, Columbus, OH, USA.
Ramakrishnan
Rajasekhar
R
Montine
Thomas J
TJ
Bray
Tammy M
TM
Traber
Maret G
MG
D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D001205:Ascorbic Acid / Q000097:blood*; D002839:Chromans / Q000652:urine; D005260:Female; D006801:Humans; D028421:Isoprostanes / Q000097:blood; D008297:Male; D018384:Oxidative Stress; D011422:Propionates / Q000652:urine; D012907:Smoking; D024502:alpha-Tocopherol / Q000097:blood* / Q000652:urine
D000975:Antioxidants; D002839:Chromans; D028421:Isoprostanes; D011422:Propionates; C084852:2,5,7,8-tetramethyl-2-(2'-carboxyethyl)-6-hydroxychroman; D024502:alpha-Tocopherol; D001205:Ascorbic Acid