Curcumin and Boswellia for knee osteoarthritis

Relation

Haroyan A, Mukuchyan V, Mkrtchyan N, et al. Efficacy and safety of curcumin and its combination with boswellic acid in osteoarthritis: a comparative, randomized, double-blind, placebo-controlled study.BMC Complement Aging Med. 2018;18(7):1-16.

Objective

To evaluate the safety and effectiveness of curcumin extract alone and in combination with boswellic acid in the treatment of knee osteoarthritis (OA).

Draft

This was a comparative, randomized, double-blind, placebo-controlled study. Subjects were randomized into 1 of 3 groups: curcumin only, curcumin combined with boswellic acid, and placebo.

Participant

The study involved 201 men and women aged 40 to 77 years (mean: 56.2 years) with radiologically confirmed degenerative hypertrophic osteoarthritis of the knee joints. Between September 2014 and May 2016, individuals were enrolled from health centers in Yerevan, Armenia. The cohort was predominantly female (93%) and the average body mass index (BMI) was 29 (range: 18-49).

Participants were excluded if they had secondary or inflammatory arthritis, history of meniscal tear, grade 2-3 synovitis, or recent (within the previous 3 months) intra-articular injection of hyaluronate or glucocorticoids. Individuals who were smokers, drug addicts, pregnant, breastfeeding, or with serious chronic illnesses were also excluded. The researchers prohibited the use of analgesics for 2 weeks before the study and the use of glucosamine or chondroitin supplements for 3 months before the study.

intervention

The curcumin intervention was BCM-95, a patented extraction containing 500 mg of curcuminoids and 50 mg of essential oils per capsule. The curcumin/boswellia intervention contained 350 mg curcuminoids (BCM-95) and 150 mg curcuminoidsBoswellia SerrataGum resin extract (75% boswellic acid) per capsule.

Placebo capsules were a mixture of excipients designed to replicate the look and smell of the intervention capsules. These excipients included maltodextrin, calcium phosphate, gelatin, magnesium stearate, silica, FD&C Yellow 5, FD&C Yellow 6 and titanium dioxide.

These benefits exceeded the placebo effect after 12 weeks of supplementation, and AEs were uncommon and minor.

All participants took 1 capsule (containing either curcumin, the combination, or placebo) three times daily for 12 weeks.

Study parameters assessed

Investigators assessed arthritis symptoms (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]), physical performance (Osteoarthritis Research Society International [OARSI]), serum inflammatory markers (erythrocyte sedimentation rate [ESR] and C-reactive protein [CRP]), and BMI. Each parameter was assessed at baseline, 4 weeks and 12 weeks. To assess safety/side effects, they asked participants to contact the investigators if they experienced any side effects or illnesses during the course of the study.

The WOMAC is a questionnaire that assesses joint pain (0-20), morning stiffness (0-8), and physical functioning (0-68), with higher scores representing more severe OA symptoms. The OARSI physical performance assessment includes the following: Maximum number of chair stand repetitions (Chair Stand Test [CST]) in 30 seconds (30s-CST); Walking time of 40 meters (40-meter rapid walk test [FPWT]); time required to stand up from a chair, walk 3 meters, go back to the chair and sit down (“timed up and go” [TUG]); and the time required to ascend and descend a 9-step staircase (stair climbing test [SCT]).

Primary outcome measures

The primary efficacy endpoints included WOMAC index score and OARSI physical performance test results. The primary measure of safety was participant reports of adverse events (AEs).

Key insights

Only the combination curcumin/boswellia group showed a statistically significant decrease in total WOMAC score compared to placebo; The index values ​​fell from an average of 33.06 to 26.49 after 12 weeks of treatment. When the researchers analyzed the subsections of WOMAC, they found statistically significant reductions in pain scores in both treatment groups; the effect size compared to placebo was 0.50 for curcumin and 0.37 for the combination curcumin/boswellia. In terms of morning stiffness and physical function, researchers found a statistically significant improvement in the within-group comparison for the treatment groups, but there was no significant improvement when each group was compared to placebo. This is attributed in part to the placebo effect observed in WOMAC index scores between baseline and week 4 (the placebo group showed significantly improved scores at week 4 but insignificant improvement at week 12).

All OARSI clinical performance measures improved with the combination supplementation intervention. The curcumin group showed improvement in every measurement except the TUG test. The effect size of improvement over placebo for each intervention was as follows:

• 30s-CST: Nur Curcumin, 0,50; Curcumin/Boswellia, 0,63
• 40 m FPWT: Nur Curcumin, 0,38; Curcumin/Boswellia, 0,32
• TUG: Nur Curcumin, 0,53; Curcumin/Boswellia, 0,38 (nicht statistisch signifikant)
• SCT: Nur Curcumin, 0,38; Curcumin/Boswellia, 0,45

A total of 13 AEs were reported during the course of the study, none of them serious. Adverse events were distributed among the 3 groups (placebo, 4 events; curcumin, 7 events; curcumin/boswellia, 2 events); However, nausea was only reported in the treatment groups.

Blood markers of chronic inflammation did not differ significantly between treatment and control groups. All groups had a significant increase in ESR and CRP over the course of the study, but values ​​remained within normal limits (ESR, 2-15 mm/h; CRP < 5 mg/L).

Practice implications

This study demonstrated modest but statistically significant benefits of curcuminoids alone and in combination with boswellic acid on knee OA pain and associated functional limitations. These benefits exceeded the placebo effect after 12 weeks of supplementation, and AEs were uncommon and minor.

The combination of curcumin/boswellia was consistently more effective in the primary outcome measures, and this higher performance may be attributed to the synergistic effects of the individual components on the pathophysiology of the disease. In vitro and animal studies have shown that curcuminoids modulate inflammation, reduce chondrocyte catabolism and apoptosis, and increase apoptosis of adherent synovial cells.^1-3Boswellic acid reduces leukocyte infiltration into the knee joint (thereby reducing inflammation), prevents collagen breakdown and inhibits pro-inflammatory mediators.^4-6

When developing a treatment plan, integrative medicine practitioners often use multiple modalities to achieve synergistic benefits. Nutraceutical therapies can be weaker than their pharmaceutical counterparts, and they often require more frequent dosing over longer periods of time to achieve the full therapeutic effect. This usually also means that the natural products have fewer serious side effects. Therefore, if a person wants an alternative to nonsteroidal anti-inflammatory medications for their OA symptoms, an integrative medicine professional is unlikely to swap that medication for a single nutraceutical intervention without additional recommendations.

Exercise is an effective non-pharmacological intervention for knee OA. There is strong evidence that it improves pain, function and quality of life in people with this disease.⁷Similarly, weight optimization is essential for both reducing stress on joints and reducing inflammatory cytokines produced by adipose tissue.⁸

An integrative medicine practitioner may also consider additional natural therapies that target other aspects of knee OA pathogenesis with the goal of providing synergistic benefits. For example, oral glucosamine sulfate and chondroitin sulfate have been shown to slow disease progression.⁹ and acupuncture can help relieve pain from osteoarthritis of the peripheral joints.¹⁰

In the present study, neither curcumin alone nor the curcumin/boswellia combination was a miracle supplement for knee OA, but both were modestly beneficial for pain and function. They would be helpful additions to a comprehensive integrative medicine treatment plan.

Limitations of the study include the sample size (N = 201) and short duration (12 weeks).