9 augustus 2005: Bron: Int J Cancer. 2005 Aug 20;116(2):182-6. en Medscape

Antioxidanten zoals vitamine C, vit. E en Betacaroteen en de mineralen zink en selenium werken significant preventief op risico van prostaatkanker (hazard ratio = 0.52; 95% CI = 0.29-0.92). blijkt uit langjarige (8 jaar) placebo gecontroleerde studie bij 5141 mannen met normale PSA waarden. Echter bij mannen met bij aanvang verhoogde PSA waarden bleken de antioxidanten eerder een negatief effect te hebben (hazard ratio = 1.54; 95% CI = 0.87-2.72). blijkt ook uit deze studie. Andere studies geven wel beschermend effect van bepaalde antioxidanten en mineralen overigens. Raadpleeg aub altijd een goed gekwalificeerd orthomoleculair arts  als u voedingssupplementen wilt gaan gebruiken.

Int J Cancer. 2005 Aug 20;116(2):182-6

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.
Laval University Cancer Research Center, Quebec, Canada. francois.meyer@chuq.qc.ca

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. Copyright 2005 Wiley-Liss, Inc.

Publication Types:
Clinical Trial
Multicenter Study
Randomized Controlled Trial

PMID: 15800922 [PubMed - indexed for MEDLINE]

Bron: Medscape

Antioxidant Vitamin and Mineral Supplementation May Help Prevent Prostate Cancer

NEW YORK (Reuters Health) Aug 05 - The use of antioxidant vitamin and mineral supplements is associated with a lower incidence of prostate cancer among men with normal prostate specific antigen (PSA) levels.
Dr. Francois Meyer from Laval University Cancer Research Center, Quebec City, colleagues assessed whether daily supplementation with antioxidant vitamins (vitamin C, vitamin E and beta-carotene) and minerals (selenium and zinc) reduced the occurrence of prostate cancer or influenced its biochemical markers.
More than 5000 men were randomized to the supplements or placebo. Biochemical marker data were available at baseline and median follow-up of about 9 years for 3616 men.

Supplementation was associated with a 48% reduction in the incidence of prostate cancer among men with a baseline PSA level below 3 micrograms/L, the authors report in the August 20th International Journal of Cancer.
In contrast, men with a baseline PSA level of 3 micrograms/L or greater who took supplements experienced a 54% increase in the incidence of prostate cancer.
Baseline vitamin C levels showed a similar pattern, the researchers note.
Antioxidant vitamin and mineral supplementation had no clear impact on the levels of five biomarkers of prostate cancer, the report indicates.
"Our study results support the hypothesis that chemoprevention of prostate cancer can be achieved with antioxidant vitamins and minerals," the investigators conclude.
They recommend additional trials "to identify the best preventative agent or combination of agents and to determine which dosages are both safe and effective."

Int J Cancer 2005;116:182-186.

preventie, prostaatkanker, mineralen, vitamines, antioxidanten

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• Antioxidanten en mineralen - vitamines C, E en betacaroteen plus zink en selenium - verminderen kans op krijgen van prostaatkanker bij mannen met normale PSA waarden met ca. 40 procent

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• Antioxidanten: Een mix van voedingsupplementen soja, isoflavones, lycopeen, silymarin en antioxidanten - vermindert de PSA stijging significant bij prostaatkankerpatiënten na operatieve ingreep of bestraling als postoperatieve behandeling