Effect of a Mediterranean Type Diet on Inflammatory and Cartilage Degradation Biomarkers in Patients with Osteoarthritis.

OBJECTIVES

To investigate the effects of a Mediterranean type diet on patients with osteoarthritis (OA).

PARTICIPANTS

Ninety-nine volunteers with OA (aged 31 - 90 years) completed the study (83% female).

SETTING

Southeast of England, UK.

DESIGN

Participants were randomly allocated to the dietary intervention (DIET, n = 50) or control (CON, n = 49). The DIET group were asked to follow a Mediterranean type diet for 16 weeks whereas the CON group were asked to follow their normal diet.

MEASUREMENTS

All participants completed an Arthritis Impact Measurement Scale (AIMS2) pre-, mid- and post- study period. A subset of participants attended a clinic at the start and end of the study for assessment of joint range of motion, ROM (DIET = 33, CON = 28), and to provide blood samples (DIET = 29, CON = 25) for biomarker analysis (including serum cartilage oligomeric matrix protein (sCOMP) (a marker of cartilage degradation) and a panel of other relevant biomarkers including pro- and anti-inflammatory cytokines).

RESULTS

There were no differences between groups in the response of any AIMS2 components and most biomarkers (p > 0.05), except the pro-inflammatory cytokine IL-1α, which decreased in the DIET group (47%, p = 0.010). sCOMP decreased in the DIET group by 1 U/L (8%, p = 0.014). There was a significant improvement in knee flexion and hip rotation ROM in the DIET group (p < 0.05).

CONCLUSIONS

The average reduction in sCOMP in the DIET group (1 U/L) represents a meaningful change, but the longer term effects require further study.