Dietary Soy Supplement on Fibromyalgia Symptoms: A Randomized, Double-Blind, Placebo-Controlled, Early Phase Trial. (23rd June 2011)

• Record Type: Journal Article
• Authors: Wahner-Roedler, Dietlind L.; Thompson, Jeffrey M.; Luedtke, Connie A.; King, Susan M.; Cha, Stephen S.; Elkin, Peter L.; Bruce, Barbara K.; Townsend, Cynthia O.; Bergeson, Jody R.; Eickhoff, Andrea L.; Loehrer, Laura L.; Sood, Amit; Bauer, Brent A.
• Is Part Of: Evidence-based complementary and alternative medicine. Volume 2011(2011)
• Publication Date: 2011-06-23
• Subjects: Alternative medicine -- Periodicals; 615.505
• DOI: 10.1093/ecam/nen069
• Languages: English
• ISSNs: 1741-427X

Abstract

Abstract : Most patients with fibromyalgia use complementary and alternative medicine (CAM). Properly designed controlled trials are necessary to assess the effectiveness of these practices. This study was a randomized, double-blind, placebo-controlled, early phase trial. Fifty patients seen at a fibromyalgia outpatient treatment program were randomly assigned to a daily soy or placebo (casein) shake. Outcome measures were scores of the Fibromyalgia Impact Questionnaire (FIQ) and the Center for Epidemiologic Studies Depression Scale (CES-D) at baseline and after 6 weeks of intervention. Analysis was with standard statistics based on the null hypothesis, and separation test for early phase CAM comparative trials. Twenty-eight patients completed the study. Use of standard statistics with intent-to-treat analysis showed that total FIQ scores decreased by 14% in the soy group ( P = .02) and by 18% in the placebo group ( P < .001). The difference in change in scores between the groups was not significant ( P = .16). With the same analysis, CES-D scores decreased in the soy group by 16% ( P = .004) and in the placebo group by 15% ( P = .05). The change in scores was similar in the groups ( P = .83). Results of statistical analysis using the separation test and intent-to-treat analysis revealed no benefit of soy compared with placebo. Shakes that contain soy and shakes that contain casein, when combined with a multidisciplinary fibromyalgia treatment program, provide a decrease in fibromyalgia symptoms. Separation between the effects of soy and casein (control) shakes did not favor the intervention. Therefore, large-sample studies using soy for patients with fibromyalgia are probably not indicated.