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

Editor's Notes:

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."