Long-term alpha-tocopherol supplementation is associated with lower serum vascular endothelial growth factor levels.
BACKGROUND
We previously reported that daily supplementation with alpha-tocopherol reduced prostate cancer risk in a large, randomized trial, the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. One potential mechanism explaining this is that alpha-tocopherol inhibited tumor angiogenesis, an effect demonstrated in animal models.


METHODS
We evaluated whether long-term supplementation with alpha-tocopherol modified serum vascular endothelial growth factor (VEGF) levels, a cytokine integrally involved in angiogenesis, in men who were not diagnosed with cancer and had baseline and follow-up blood available. One hundred of these men who received alpha-tocopherol (50 mg daily) were randomly selected and matched on age, study center and time between blood draws to 100 men who received placebo (median follow-up 3.7 years). VEGF levels were measured by enzyme-linked immunosorbent assay. The effect of alpha-tocopherol supplementation on serum VEGF was evaluated using a matched-paired t-test for differences in the change in VEGF over the intervention period between groups.


RESULTS
There was an 11% reduction in VEGF levels in the alpha-tocopherol group as compared with a 10% increase in the placebo group (p=0.03).


CONCLUSIONS
Our findings suggest that one of the mechanisms behind the inhibition of prostate carcinogenesis by alpha-tocopherol in the ATBC Study may have been through reduced VEGF concentrations and the suppression of tumor angiogenesis and therefore growth.
Woodson
Karen
K
Cancer Prevention Studies Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA. kw114v@nih.gov
Triantos
Spyros
S
Hartman
Terryl
T
Taylor
Philip R
PR
Virtamo
Jarmo
J
Albanes
Demetrius
D
D000368:Aged; D000428:Alcohol Drinking / Q000097:blood; D000975:Antioxidants / Q000008:administration & dosage* / Q000494:pharmacology; D015331:Cohort Studies; D019587:Dietary Supplements; D004334:Drug Administration Schedule; D016228:Endothelial Growth Factors / Q000097:blood*; D006801:Humans; D008222:Lymphokines / Q000097:blood*; D008297:Male; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic; D012907:Smoking / Q000097:blood; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D024502:alpha-Tocopherol / Q000008:administration & dosage* / Q000494:pharmacology
D000975:Antioxidants; D016228:Endothelial Growth Factors; D008222:Lymphokines; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D024502:alpha-Tocopherol