Nieman DC, Shanely RA, Luo B, Dew D, Meaney MP, Sha W. A commercialized dietary supplement alleviates joint pain in community adults: a double-blind, placebo-controlled community trial. Nutr J. November 25, 2013;12(1):154. doi: 10.1186/1475-2891-12-154.
Debilitating joint pain increases with age, reaching 50% prevalence among the elderly. A 2012 study reported that 47% of affected people use alternative treatments such as chondroprotective supplements and anti-inflammatory herbs. This 8-week randomized, double-blind, placebo-controlled trial evaluated the effects of Instaflex™ Joint Support (Direct Digital; Charlotte, North Carolina) on joint pain, stiffness, physical function, and inflammatory biomarkers in subjects suffering from joint pain.
"The Instaflex supplement contained the following ingredients (in 3 capsules): Glucosamine sulfate (1500 mg), methylsufonlylmethane [sic] (MSM) (500 mg), white willow [Salix alba] bark extract (standardized to 15% salicin) (250 mg), ginger [Zingiber officinale] root concentrate (50 mg), boswella serrata [sic] extract (standardized to 65% boswellic acid) (125 mg), turmeric [Curcuma longa] root extract (50 mg), cayenne [Capsicum annuum] 40 m H.U. (50 mg), and hyaluronic acid (4.0 mg)." Data substantiating the source, identity, purity, and potency of the ingredients was not reported.
This study included 108 subjects of both genders, aged between 50-75 years, with self-reported history (˃3 months) of joint pain in the knees, hip, ankles, shoulders, or hands, and symptom severity of at least 2 points on the WOMAC (Western Ontario and McMaster Universities) index. Included subjects did not consume non-steroidal anti-inflammatory drugs (NSAIDs) or other medications for joint pain in the 2 weeks prior to the study, were not on other medications, did not have medical or psychiatric problems, were able to walk for 6 minutes at a moderate-to-brisk speed, and had no allergy to shellfish or aspirin.
Subjects were randomly assigned to take either an Instaflex or placebo (magnesium stearate) capsule 3 times a day for 8 weeks. The primary outcome was change in joint pain severity, stiffness, and function measured using the WOMAC index; subjects rated joint pain (5 questions), stiffness (2 questions), and physical function (16 questions) on a scale ranging from 0 (none) to 4 (extreme). Secondary outcome measures included a health-related quality-of-life questionnaire (Short Form 36 or SF-36), systemic inflammation (serum C-reactive protein and 9* plasma cytokines), and physical function (6-minute walk test). Symptom severity was assessed bi-weekly using a 12-point Likert visual scale (12-VS). Bi-weekly email responses and end-of-study pill counts indicated 100% compliance with the therapeutic regimen.
There was no significant difference between groups at baseline. In total, 100 subjects finished the trial and based on body mass index data, 85% were overweight or obese. The majority of subjects reported knee pain (74.2%) and upper limb joint pain (55.7%). In addition, 41.2% had hip pain, 24.7% had lower limb joint pain, and 18.6% had back pain.
Compared to placebo, WOMAC joint pain severity scores decreased significantly (P=0.025) in the Instaflex group and the decrease in total WOMAC scores approached statistical significance (P=0.074). There was no significant change in WOMAC joint stiffness or joint function scores.
Sub-group analysis of the subjects reporting knee pain (74%) indicated that Instaflex significantly decreased total WOMAC scores (P=0.018), as well as joint pain (P=0.014) and function (P=0.027) scores. The decrease in joint stiffness scores approached statistical significance (P=0.081).
Based upon the data recorded in the bi-weekly symptom logs, joint pain severity was significantly lessened in the Instaflex group as compared to placebo after 4 weeks of treatment (**P=0.0125), but there were no significant differences in the other 8 categories. There were no significant differences between treatment groups in the SF-36 questionnaire results, inflammation marker concentrations, diagnostic blood chemistry panels, or 6-minute walking tests.
In summary, this study provides evidence that Instaflex may be effective in reducing joint pain severity although no measureable impacts on quality of life, inflammation markers, 6-minute walking distance, or metabolic parameters were observed in this population. The authors conclude, "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."
—Amy C. Keller, PhD
This article was very skillfully written. Some seemingly conflicting data were denoted with asterisks.
*The article abstract states that secondary outcome measures included "9 plasma cytokines," but the methods and results sections indicate that, "Total plasma concentrations of four inflammatory cytokines (interleukin-6 [IL-6], tumor necrosis factor alpha [TNFα], IL-8, and IL-10) were determined."
**This statistically significant student t-test result (P=0.0125) by week 4 of the study is reported in both the abstract and body text of the article. However, the data presented in the results section (Figure 4) are as follows: P=0.039 at 4 weeks, P=0.019 at 6 weeks, and P=0.080 at 8 weeks.
The authors report that, "This study was funded by Direct Digital. Direct Digital provided the Instaflex and placebo supplements used in this study."