1.
Antioxidant vitamin and mineral supplementation and prostate cancer prevention in the SU.VI.MAX trial.
Meyer, F, Galan, P, Douville, P, Bairati, I, Kegle, P, Bertrais, S, Estaquio, C, Hercberg, S
International journal of cancer. 2005;(2):182-6
-
-
Free full text
-
Abstract
Randomized trials have shown, unexpectedly, that supplementation with selenium or vitamin E is associated with a reduction of prostate cancer risk. We assess whether a supplementation with low doses of antioxidant vitamins and minerals could reduce the occurrence of prostate cancer and influence biochemical markers. The SU.VI.MAX trial comprised 5,141 men randomized to take either a placebo or a supplementation with nutritional doses of vitamin C, vitamin E, beta-carotene, selenium and zinc daily for 8 years. Biochemical markers of prostate cancer risk such as prostate-specific antigen (PSA) and insulin-like growth factors (IGFs) were measured on plasma samples collected at enrollment and at the end of follow-up from 3,616 men. Cox regression models were used to estimate the hazard ratio and related 95% confidence interval of prostate cancer associated with the supplementation and to examine whether the effect differed among predetermined susceptible subgroups. During the follow-up, 103 cases of prostate cancer were diagnosed. Overall, there was a moderate nonsignificant reduction in prostate cancer rate associated with the supplementation (hazard ratio = 0.88; 95% CI = 0.60-1.29). However, the effect differed significantly between men with normal baseline PSA (< 3 microg/L) and those with elevated PSA (p = 0.009). Among men with normal PSA, there was a marked statistically significant reduction in the rate of prostate cancer for men receiving the supplements (hazard ratio = 0.52; 95% CI = 0.29-0.92). In men with elevated PSA at baseline, the supplementation was associated with an increased incidence of prostate cancer of borderline statistical significance (hazard ratio = 1.54; 95% CI = 0.87-2.72). The supplementation had no effect on PSA or IGF levels. Our findings support the hypothesis that chemoprevention of prostate cancer can be achieved with nutritional doses of antioxidant vitamins and minerals.
2.
Association of selenium with thyroid volume and echostructure in 35- to 60-year-old French adults.
Derumeaux, H, Valeix, P, Castetbon, K, Bensimon, M, Boutron-Ruault, MC, Arnaud, J, Hercberg, S
European journal of endocrinology. 2003;(3):309-15
Abstract
OBJECTIVE To investigate the relationship between selenium status, thyroid Volume and gland echostructure. DESIGN Cross-sectional. METHODS In 792 men (45-60 Years) and 1108 women (35-60 Years) from the SU.VI.MAX study, thyroid Volume and gland echostructure were determined ultrasonographically. At baseline, thyrotropin, free thyroxine, selenium, zinc, alpha-tocopherol, beta-carotene, retinol, urinary iodine and thiocyanate concentrations were measured. Alcohol consumption, smoking, and menopausal status were assessed by a questionnaire. A stepwise linear and a logistic regression model were used, adjusting for antioxidant vitamins, trace elements status and age. RESULTS In women, there was an inverse association between selenium status and thyroid Volume (P=0.003). A protective effect of selenium against goiter (odds ratio (OR)=0.07, 95% confidence interval (CI)=0.008-0.6) and thyroid tIssue damage (OR=0.2, 95% CI=0.06-0.7) was observed. There was no evidence of an association between menopausal status and other antioxidant elements, thyroid Volume or thyroid hypoechogenicity. Smoking, but not alcohol consumption, was associated with an increased risk of thyroid enlargement in women (OR=3.94, 95% CI=1.64-9.48). No association between thyroid Volume, thyroid structure or selenium was found in men. CONCLUSION Our findings suggest that selenium may protect against goiter. Selenium was related to thyroid echostructure, suggesting it may also protect against autoimmune thyroid disease.