Effects of gamma-tocopherol supplementation on thrombotic risk factors.
OBJECTIVE
The antioxidant activity of vitamin E is derived primarily from alpha-tocopherol (alpha-T) and gamma-tocopherol (gamma-T). Results of epidemiological studies have demonstrated an inverse relationship between vitamin E intake and coronary disease. However, the results of clinical trials using alpha-T are equivocal. We determined the effect of 5 weeks of 100 mg/d or 200 mg/d gamma-T supplementation on thrombotic markers such as platelet reactivity, lipid profile and the inflammation marker C-reactive protein (CRP).


RESULTS
Fourteen healthy subjects consumed 100 mg/day while 13 consumed 200 mg/d of gamma-T and 12 received placebo (soybean capsules with less than 5 mg/d gamma-T) in a double-blinded parallel study design. Fasting pre and post dose blood samples were analysed. Blood gamma-T concentrations increased significantly (p<0.05) relative to dose during the intervention period. Both groups receiving active ingredients showed significantly lower platelet activation after supplementation (p<0.05). Subjects consuming 100 mg/d gamma-T had significantly decreased LDL cholesterol, platelet aggregation and mean platelet volume (MPV) (p<0.05). Little effect of gamma-T was observed on other parameters.


CONCLUSIONS
These data suggest that gamma-T supplementation may have a permissive role in decreasing the risk of thrombotic events by improving lipid profile and reducing platelet activity.
Singh
Indu
I
Division of Laboratory Medicine, School of Medical Sciences, RMIT University, PO Box 71, Bundoora, Victoria 3083, Australia. indu.singh@rmit.edu.au
Turner
Alan H
AH
Sinclair
Andrew J
AJ
Li
Duo
D
Hawley
John A
JA
D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage* / Q000378:metabolism; D001792:Blood Platelets / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism; D008078:Cholesterol, LDL / Q000097:blood*; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D005215:Fasting; D005260:Female; D006801:Humans; D008055:Lipids / Q000097:blood; D008297:Male; D015539:Platelet Activation / Q000187:drug effects; D010974:Platelet Aggregation / Q000187:drug effects*; D012307:Risk Factors; D013927:Thrombosis / Q000097:blood* / Q000517:prevention & control; D024504:gamma-Tocopherol / Q000008:administration & dosage* / Q000097:blood*
D000975:Antioxidants; D008078:Cholesterol, LDL; D008055:Lipids; D024504:gamma-Tocopherol; D002097:C-Reactive Protein