Supplemental and dietary vitamin E, beta-carotene, and vitamin C intakes and prostate cancer risk.
Cast your vote
You can rate an item by clicking the amount of stars they wish to award to this item.
When enough users have cast their vote on this item, the average rating will also be shown.
Your vote was cast
Thank you for your feedback
Thank you for your feedback
AuthorsKirsh, Victoria A.
Hayes, Richard B.
Mayne, Susan T.
Subar, Amy F.
Dixon, L. Beth
Andriole, Gerald L.
Urban, Donald A.
MetadataShow full item record
AbstractBACKGROUND: Vitamin E, beta-carotene, and vitamin C are micronutrient antioxidants that protect cells from oxidative damage involved in prostate carcinogenesis. In separate trials, supplemental vitamin E was associated with a decreased risk of prostate cancer among smokers and supplemental beta-carotene was associated with a decreased risk of prostate cancer among men with low baseline plasma beta-carotene levels. METHODS: We evaluated the association between intake of these micronutrient antioxidants from foods and supplements and the risk of prostate cancer among men in the screening arm of the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. At baseline, trial participants completed a 137-item food frequency questionnaire that included detailed questions on 12 individual supplements. Cox proportional hazards models were used to estimate relative risks (RRs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS: We identified 1338 cases of prostate cancer among 29 361 men during up to 8 years of follow-up. Overall, there was no association between prostate cancer risk and dietary or supplemental intake of vitamin E, beta-carotene, or vitamin C. However, among current and recent (i.e., within the previous 10 years) smokers, decreasing risks of advanced prostate cancer (i.e., Gleason score > or = 7 or stage III or IV) were associated with increasing dose (RR for > 400 IU/day versus none = 0.29, 95% CI = 0.12 to 0.68; Ptrend = .01) and duration (RR for > or = 10 years of use versus none = 0.30, 95% CI = 0.09 to 0.96; Ptrend = .01) of supplemental vitamin E use. Supplemental beta-carotene intake at a dose level of at least 2000 microg/day was associated with decreased prostate cancer risk in men with low (below the median of 4129 microg/day) dietary beta-carotene intake (RR = 0.52, 95% CI = 0.33 to 0.81). Among smokers, the age-adjusted rate of advanced prostate cancer was 492 per 100,000 person-years in those who did not take supplemental vitamin E, 153 per 100,000 person-years in those who took more than 400 IU/day of supplemental vitamin E, and 157 per 100,000 person-years in those who took supplemental vitamin E for 10 or more years. Among men with low dietary beta-carotene intake, the age-adjusted rate of prostate cancer was 1122 per 100,000 person-years in those who did not take supplemental beta-carotene, and 623 per 100,000 person-years in those who took at least 2000 microg/day of supplemental beta-carotene. CONCLUSIONS: Our results do not provide strong support for population-wide implementation of high-dose antioxidant supplementation for the prevention of prostate cancer. However, vitamin E supplementation in male smokers and beta-carotene supplementation in men with low dietary beta-carotene intakes were associated with reduced risk of this disease.
CitationJ. Natl. Cancer Inst. 2006, 98 (4):245-254
DescriptionDietary modulation of cancer & cancer biomarkers Dietary item or component studied: Vitamin E, caroteniods, vitamin COutcome studied (cancer or cancer biomarker): prastate cancerStudy type (in vitro, animals, humans): humansStudy design (if human): cross-sectionalStudy size (if human):29361 menMode of exposure (if in vivo): through normal diet (no administration)Impact on outcome (including dose-response): inverse association between β-carotene intake and prostate cancer risk (RR for >2000μg/day vs none=0.52, 95%CI=0.33-0.81)notes:No association between risk and a-β-γ-δ-tocopherol(P=0.63, 0.12, 0.34, 0.71), respectively. KEYWORDS CLASSIFICATION: administration & dosage;adverse effects;Adult;Aged;Anticarcinogenic Agents;Antioxidants;Ascorbic Acid;beta Carotene;cancer epidemiology;dietary modulation of cancer & cancer biomarkers;Dietary Supplements;epidemiology;etiology;Humans;Incidence;Lung;mortality;Male;Mass Screening;Middle Aged;prevention & control;Prostate;Prostatic Neoplasms;Research;Risk Assessment;Smoking;Treatment Outcome;United States;Vitamin E.