Efficacy of Antioxidant Vitamins and Selenium Supplement in Prostate Cancer Prevention: A Meta-Analysis of Randomized Controlled Trials

Abstract

Several studies have evaluated the possible association between antioxidants vitamins or selenium supplement and the risk of prostate cancer, but the evidence is still inconsistent. We systematically searched PubMed, EMBASE, the Cochrane Library, Science Citation Index Expanded, Chinese biomedicine literature database, and bibliographies of retrieved articles up to January 2009. We included 9 randomized controlled trials with 165,056 participants; methodological quality of included trials was generally high. Meta-analysis showed that no significant effects of supplementation with beta-carotene (RR 0.97, 95% CI 0.90-1.05) (3 trials), vitamin C (RR 0.98, 95% CI 0.91-1.06) (2 trials), vitamin E (RR 0.96, 95% CI 0.85-1.08) (5 trials), and selenium (RR 0.78, 95% CI 0.41-1.48) (2 trials)versus placebo on prostate cancer incidence. The mortality of prostate cancer did not differ significantly by supplement of beta-carotene (RR 1.19, 95% CI 0.87 -1.65) (1 trial), vitamin C (RR 1.45, 95%CI 0.92-2.29) (1 trial), vitamin E (RR 0.85, 95%CI 0.58-1.24) (2 trials), and selenium (RR 2.98, 95% CI 0.12-73.16) (1 trial). Our findings indicate that antioxidant vitamins and selenium supplement did not reduce the incidence and mortality of prostate cancer, these data provide no support for the use of these supplements for the prevention of prostate cancer.

Effects of Light Quality on Growth and Phytonutrient Accumulation of Herbs under Controlled Environments

“…Large amounts of ROS may favor human disease such as cancers, cardiovascular diseases, aging, and neurodegenerative diseases [64]. Therefore, the daily intake of exogenous antioxidants is beneficial for protecting the human body against the destructive effects of free radicals [65,66].…”

Changes in Expression of the Antioxidant Enzyme SOD3 Occur Upon Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells In Vitro

“…Although preclinical evidence suggests a benefit of antioxidant therapies, antioxidant use in clinical practice is limited and systematic reviews report mixed outcomes of antioxidants. Specifically, conditions investigated by systematic reviews include various cancers [29][30][31][32], diabetes [33,34], cardiovascular disease [35][36][37], and neurodegenerative conditions [38][39][40]. Thus future studies are required to provide robust evidence for the potential of specific pharmaceuticals and cellular therapies, such as hMSCs, as alternative sources of antioxidants to promote antioxidant use in clinical practice.…”

Prevention and early detection of prostate cancer

“…Trials of agents found in the diet which were thought to have a beneficial impact on prostate cancer have been disappointingly negative 65 . Early randomised studies of the role of beta-carotene in those at high risk of the lung cancer showed an increase in lung cancer, as well as stomach cancer.…”