Bone as a Biomarker of Ageing and Senescence: Connecting Musculoskeletal Health to Longevity via Diet, Nutrition and Exercise

Advancing age is often accompanied by a gradual decline in musculoskeletal (MSK) health and integrity, making the skeleton not just a structural framework; but a dynamic indicator of biological ageing. Bone tissue undergoes continuous remodelling through tightly regulated interactions among osteocytes, osteoblasts, osteoclasts, progenitor cells or mesenchymal stem/stromal cells (MSCs) and growth factors. With advancing age, this balance shifts toward increased resorption, increased adipose tissue formation, reduced bone formation, and deterioration of bone microarchitecture. This eventually can lead to frailty, increased fracture risk and other age-related diseases (ARDs) due to ageing, cellular senescence and inflammaging. Interestingly, bone-derived changes often precede clinical manifestations of these ARDs, suggesting its potential use as an early biomarker for biological ageing and longevity risks. In our review, we explore the possibility of using the bone as a biomarker for ageing, followed by anti-ageing strategies to encourage bone longevity. We begin by discussing our current knowledge of the bone, the bone marrow (BM), changes in the BM with ageing and current methods of tracking bone ageing; both clinically and experimentally. We then explore studies that investigated the anti-ageing strategies, specifically focused on diet, exercises and lifestyle to shift towards enhanced bone health and longevity. Finally, we discuss the limitations of achieving this, what the future of this field may look like and what methods may be used to translate the idea of bone as a biomarker of ageing, from bench to bed.