A composition contains at least one of homovanillyl alcohol (HVA) or its previously unidentified isomer (isoHVA). Additionally or alternatively, the composition contains a precursor of HVA and/or isoHVA (e.g., hydroxytyrosol, oleuropein aglycone, oleuropein, demethyloleuropein, oleuroside, verbascoside or mixtures thereof) and also contains at least one probiotic and/or at least one enzyme which convert the precursor to HVA and/or isoHVA in vivo (and/or an intermediate compound then subjected to methylation in vivo to form HVA and/or isoHVA). The composition can be administered to an individual to treat or reduce incidence of impaired mobility in an older adu stimulate bone formation and/or inhibit bone resorption; treat or reduce incidence of synovitis in an individual in need or at risk thereof; treat or reduce incidence of articular cartilage degradation subsequent to synovitis in an individual having or recovering from synovitis; or treat or reduce incidence of cartilage breakdown.; 展开▼