High-fat diet exacerbates the loss of bone fracture toughness in aging for C57BL/6JN mice

The elderly are at increased risk of bone fracture and more often consume poor quality diets, such as high-fat diet (HFD). We hypothesized that HFD would exacerbate the loss of bone fracture resistance in aging. To test this hypothesis, we fed 5-month and 22-month C57BL/6JN mice of both sexes HFD or low-fat diet for 8 weeks. Aging and HFD lowered bone fracture toughness, while only aging reduced bone strength. At the tissue-scale, aging increased bone mineral maturity, while HFD altered bone mineralization and maturity as well as collagen structure. Cortical bone metabolism was also dysregulated with aging and HFD. Dysregulated pathways in aging and HFD were related to cellular function and viability, or glucose regulation, respectively. Aging with HFD also impacted osteoclast and adipocyte abundance and osteocyte viability. Together, these data demonstrate that HFD may exacerbate the loss of bone matrix quality and fracture resistance in aging.