title: A commercialized dietary supplement alleviates joint pain in community adults: a double-blind, placebo-controlled community trial.
abstract: BACKGROUND
  The purpose of this study was to assess the effect of 8-weeks ingestion of a commercialized joint pain dietary supplement (Instaflex™ Joint Support, Direct Digital, Charlotte, NC) compared to placebo on joint pain, stiffness, and function in adults with self-reported joint pain. Instaflex™ is a joint pain supplement containing glucosamine sulfate, methylsufonlylmethane (MSM), white willow bark extract (15% salicin), ginger root concentrate, boswella serrata extract (65% boswellic acid), turmeric root extract, cayenne, and hyaluronic acid.
  
  
  METHODS
  Subjects included 100 men and women, ages 50-75 years, with a history (>3 months) of joint pain, and were randomized to Instaflex™ or placebo (3 colored gel capsules per day for 8 weeks, double-blind administration). Subjects agreed to avoid the use of non-steroidal anti-inflammatory drugs (NSAID) and all other medications and supplements targeted for joint pain. Primary outcome measures were obtained pre- and post-study and included joint pain severity, stiffness, and function (Western Ontario and McMaster Universities [WOMAC]), and secondary outcome measures included health-related quality of life (Short Form 36 or SF-36), systemic inflammation (serum C-reactive protein and 9 plasma cytokines), and physical function (6-minute walk test). Joint pain symptom severity was assessed bi-weekly using a 12-point Likert visual scale (12-VS).
  
  
  RESULTS
  Joint pain severity was significantly reduced in Instaflex™ compared to placebo (8-week WOMAC, ↓37% versus ↓16%, respectively, interaction effect P = 0.025), with group differences using the 12-VS emerging by week 4 of the study (interaction effect, P = 0.0125). Improvements in ability to perform daily activities and stiffness scores in Instaflex™ compared to placebo were most evident for the 74% of subjects reporting knee pain (8-week WOMAC function score, ↓39% versus ↓14%, respectively, interaction effect P = 0.027; stiffness score, ↓30% versus ↓12%, respectively, interaction effect P = 0.081). Patterns of change in SF-36, systemic inflammation biomarkers, and the 6-minute walk test did not differ significantly between groups during the 8-week study
  
  
  CONCLUSIONS
  Results from this randomized, double blind, placebo-controlled community trial support the use of the Instaflex™ dietary supplement in alleviating joint pain severity in middle-aged and older adults, with mitigation of difficulty performing daily activities most apparent in subjects with knee pain.
authors.affiliation: Appalachian State University, Human Performance Lab, North Carolina Research Campus, 600 Laureate Way, Kannapolis, NC 28081, USA. niemandc@appstate.edu.
authors.forename: David C
authors.initials: DC
authors.lastname: Nieman
authors.forename: R Andrew
authors.initials: RA
authors.lastname: Shanely
authors.forename: Beibei
authors.initials: B
authors.lastname: Luo
authors.forename: Dustin
authors.initials: D
authors.lastname: Dew
authors.forename: Mary Pat
authors.initials: MP
authors.lastname: Meaney
authors.forename: Wei
authors.initials: W
authors.lastname: Sha
mesh_terms: D000368:Aged; D018771:Arthralgia / Q000188:drug therapy*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D030024:Curcuma; D019587:Dietary Supplements; D004311:Double-Blind Method; D005260:Female; D020939:Zingiber officinale / Q000737:chemistry; D005944:Glucosamine / Q000008:administration & dosage*; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage; D016753:Interleukin-10 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D016209:Interleukin-8 / Q000097:blood; D008297:Male; D008875:Middle Aged; D024301:Plant Bark / Q000737:chemistry; D010936:Plant Extracts / Q000008:administration & dosage*; D018517:Plant Roots / Q000737:chemistry; D015203:Reproducibility of Results; D012189:Retrospective Studies; D032108:Salix / Q000737:chemistry; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014315:Triterpenes / Q000008:administration & dosage; D014409:Tumor Necrosis Factor-alpha / Q000097:blood
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D016209:Interleukin-8; D010936:Plant Extracts; D014315:Triterpenes; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10; C054625:boswellic acid; C012596:turmeric extract; D006820:Hyaluronic Acid; D002097:C-Reactive Protein; D005944:Glucosamine