The effects of curcuminoids on musculoskeletal pain: a systematic review

Background Western countries are increasingly using complementary and alternative medicine (CAM) to assist with relieving ailments. Turmeric, from the ginger family Zingiberaceae, has a history of use for medicinal purposes. The polyphenols found in turmeric (curcuminoids) have demonstrated anti-inflammatory and pain relieving properties. With the use of CAMs increasing, it is important for the effectiveness of curcuminoids to be established. Objectives To identify the effectiveness of the use of curcuminoids for the amelioration of musculoskeletal pain. Inclusion criteria Types of participants Persons experiencing musculoskeletal pain, including experimentally induced musculoskeletal pain. Types of intervention(s)/phenomena of interest The current review considered studies that evaluated the use of curcuminoids. Types of controls Any form including placebo, treatment as usual or before and after measurements. Types of studies Both experimental and epidemiological study designs including randomized controlled trials (RCTs), non-RCTs, quasi-experimental and before and after studies were eligible for consideration in this review. Studies published in English were considered without date restriction. Outcomes The current review considered studies that included measurement of pain. Outcome measures included visual analog scales, and/or pain questionnaires. Secondary outcome measures of functionality (activities of daily living and range of motion) were included. Any data provided on adverse events were considered. Search strategy The databases PubMed, CINAHL, Embase and ProQuest were searched in March 2015 (and updated in April 2016) using the Joanna Briggs Institute (JBI) three-step search strategy. The reference lists of identified articles were reviewed for additional studies. Methodological quality Papers selected were assessed by two independent reviewers using standardized instruments from the JBI Meta-Analysis of Statistics Assessment and Review Instrument (JBI-MAStARI). Data extraction Data were extracted using the data extraction tool from JBI-MAStARI. Data extracted included details about the populations, interventions, study methods and outcomes. Data synthesis Narrative and tabular synthesis was conducted. Meta-analysis was precluded due to methodological and clinical heterogeneity across all included studies. Results Thirteen studies with a combined total of 1101 participants were included. Three studies of limited sample size examined the effects of curcuminoids compared with the use of placebo on musculoskeletal pain, with one study showing a statistically significant effect. Four studies examined the effects of curcuminoids compared with non-selective non-steroidal anti-inflammatory drugs on musculoskeletal pain. Two of these four studies were non-inferiority studies showed that the use of both curcuminoids and ibuprofen were associated with a similar significant reduction in pain over the study durations of four and six weeks, respectively, with curcuminoid use non-inferior to the use of ibuprofen over the study durations. Six studies investigated presentations of curcuminoid-containing herbomineral mixtures versus placebo or active controls. Conclusion There is insufficient evidence to recommend that curcuminoids be considered for relieving pain and improving function in musculoskeletal pain conditions. This finding needs to be considered in the context of limitations imposed by the variability in the quality of studies, small sample sizes, short duration of interventions, a gender-bias toward females, absence of long-term data extraction and small number of relevant studies.