The Study
Protein intake and bone mineral density: Cross‐sectional relationship and longitudinal effects in older adults
This study looked at what older people ate and how strong their bones were, and found that people who ate more meat and dairy tended to have stronger bones, while those who ate more plants tended to have weaker bones. But it didn’t prove that eating more meat made bones stronger — maybe people with weaker bones just ate less meat because they didn’t feel like chewing.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
This study looked at whether eating more protein, especially from meat and dairy, helps keep bones strong in people over 65.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 567 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The bone density changes are very small—like a fraction of a penny’s weight spread over a whole bone.
- 2It’s not enough to prevent fractures on its own.
- 3People who ate more total or animal protein had slightly denser bones (0.001–0.002 g/cm² higher per gram of protein).
- 4Those who ate more plant protein had slightly less dense bones.
- 5But giving extra protein supplements for up to 24 weeks didn’t make bones denser.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of Cachexia, Sarcopenia and Muscle
Year
2022
Authors
I. Groenendijk, P. Grootswagers, A. Santoro, C. Franceschi, A. Bazzocchi, N. Meunier, A. Caille, C. Malpuech-Brugère, A. Białecka-Dębek, B. Pietruszka, S. Fairweather-Tait, A. Jennings, L. D. de Groot
Related Content
Claims (6)
In people aged 65 and older, consuming more dietary protein each day is linked to a small increase in bone mineral density at the spine and whole body, with each extra gram of protein per day associated with a 0.0011 to 0.0015 g/cm² rise in bone density after accounting for other lifestyle and nutritional factors.
In people aged 65 and older, consuming more animal protein is linked to slightly higher bone mineral density in the spine and entire body, with each extra gram of animal protein per day corresponding to a small increase in bone density measurements.
In people aged 65 and older, consuming more plant protein is linked to slightly lower bone mineral density in the spine and entire body, with each extra gram of plant protein per day associated with a small reduction in bone density.
Older adults who consume more animal protein relative to plant protein have higher bone mineral density in the spine and entire body, even when total protein intake is held constant.
Taking protein supplements for 12 to 24 weeks, with or without strength training, does not change bone mineral density in the spine or whole body in people aged 65 and older.
People who consume more dietary protein, including from animal sources, have higher bone mineral density.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.