Background: Anti-oxidant compounds that are found in over-the-counter (OTC) supplements and foods are gaining interest as treatments for multiple sclerosis (MS). They are widely used by patients, sometimes without a clear evidence base. Objective: We conducted a systematic review of animal and clinical research to determine the evidence for the benefits of OTC anti-oxidants in MS. Methods: Using predefined criteria, we searched key databases. Two authors scrutinized all studies against inclusion/exclusion criteria, assessed study risk-of-bias and extracted results. Results: Of the 3507 titles, 145 met criteria and included compounds, α(alpha)-lipoic acid (ALA), antioxidant vitamins, Ginkgo biloba, quercetin, resveratrol and epigallocatechin-3-gallate (ECGC). The strongest evidence to support OTC anti-oxidants was for compounds EGCG and ALA in animal models; both consistently showed anti-inflammatory/anti-oxidant effects and reduced neurological impairment. Only vitamin E, Ginkgo biloba and ALA were examined for efficacy in pilot clinical trials with either conflicting evidence or evidence of no benefit. Conclusion: OTC anti-oxidants EGCG and ALA show the most consistent benefit, however only in preclinical studies. There is no evidence that they alter MS relapses or progression. Future work should focus on testing more of these therapies for clinical efficacy before recommending them to MS patients. Anti-oxidant drug therapies, diets, and supplements, purported to counteract ROS and RNS cascades, are available as over-the-counter (OTC) remedies yet their benefits have not been proven. Most people with MS reporting using an OTC supplement despite the lack of a clear evidence base. 15 We undertook this study to systematically and rigorously examine current research findings on the effects of OTC anti-oxidant supplements in animal models and clinical trials in MS. Our aim was to translate research findings to MS clinicians and to identify areas for future research.
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Methods
Search strategyWith the assistance of a librarian expert in systematic reviews and using predefined search terms (Table 1), we searched PubMed, CINAHL, PsychInfo, the Cochrane Library, and the Central Register of Controlled Clinical Trials, including all years up to 1 October 2013 (English language only). Clinical studies were included if the participants had MS or the biological products tested were from people with MS. Animal studies were included if a disease, similar to MS, was induced in animals and included at least behavioral findings.
Data extraction and synthesisFollowing Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 16 and after duplicates were removed, we merged titles retrieved across search databases. At the title, abstract, and manuscript levels of the search, two authors evaluated inclusion status independently and if the authors disagreed, the article was included. Data extraction and synthesis was conducted on manuscripts that were categorized by compound tested. Referenc...
