Longitudinal associations of dietary intake, physical activity, and short-chain fatty acids with bone development in...

Bone loss accelerates in early menopause, increasing fracture risk. In 223 women followed for 2 years, higher fiber and energy intake were linked to better bone structure, while higher fat intake and some physical activity domains were inversely associated. Specific short-chain fatty acids showed positive associations, highlighting diet-microbiome interactions in bone health.

The early postmenopausal period is characterized by accelerated loss of bone mineral density (BMD), underscoring the importance of modifiable lifestyle factors as potential targets for prevention.

This study is a secondary analysis of the ELBOW trial, a 2-year longitudinal study of early postmenopausal Swedish women. We investigated the association between dietary intake, physical activity, and short-chain fatty acids (SCFAs) with bone outcomes in 223 early postmenopausal Swedish women aged 50-60 years. Assessments were conducted at baseline, 1 year, and 2 years. Diet and physical activity were assessed using validated questionnaires, and SCFAs were measured in plasma. Bone parameters, including total hip BMD, tibial volumetric BMD (vBMD), and bone microarchitecture, were evaluated using dual-energy X-ray absorptiometry (DXA) and high-resolution peripheral quantitative computed tomography (HR-pQCT). Associations were analyzed using linear mixed models for repeated measures.

Higher baseline fiber intake was positively associated with trabecular bone volume fraction, while total fat was inversely associated with total hip BMD, total vBMD, and cortical area. Greater energy intake during follow-up was positively associated with cortical area. No associations were observed between bone characteristics and calcium or vitamin D intake. Baseline transport-related and changes in domestic/gardening activity were inversely associated with bone measurements. Among SCFAs, baseline levels of acetic acid, formic acid, and isovaleric acid were positively associated with bone outcomes, while changes in caproic acid levels were negatively associated.

These findings suggest that specific dietary components and gut microbiota-derived metabolites may play a role in maintaining bone health during early postmenopause and highlight the need for further investigation into their preventive and therapeutic potential.