The Study
Effect of dietary protein intake on bone mineral density and fracture incidence in older adults in the Health, Aging, and Body Composition study.
This study watched a group of older people for five years and noticed that those who ate more protein tended to have stronger bones and fewer spine fractures. But it didn’t make them eat more protein — it just observed what they were already doing, so we can’t say protein definitely made their bones stronger.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
This study looked at what older people ate and how strong their bones were over five years.
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 560 / 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.
- 1Yes—this means eating more protein might help older adults avoid spine fractures, especially if they don’t get enough calcium, but it won’t stop bones from naturally weakening with age.
- 2People who ate more protein (at least 15% of their calories) had 2% to 6% denser bones at the hip and spine at the start, and were 64% less likely to break a spine bone over five years—but their bones still got weaker at the same rate as others over time.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The journals of gerontology. Series A, Biological sciences and medical sciences
Year
2021
Authors
A. Weaver, J. Tooze, J. Cauley, D. Bauer, F. Tylavsky, S. Kritchevsky, D. Houston
Related Content
Claims (5)
People who consume more dietary protein, including from animal sources, have higher bone mineral density.
In older adults, consuming more or less protein than 15% of daily calories does not change how quickly bone density decreases over five years.
Older adults who consume at least 15% of their daily calories from protein have a 64% lower rate of spinal bone fractures over five years compared to those with lower protein intake, even when accounting for age, sex, race, calcium intake, physical activity, and osteoporosis medications.
Older adults who get at least 15% of their daily calories from protein have 1.8% to 6.0% higher bone mineral density in the hip, femoral neck, and lower spine than those who get less than 13% of their calories from protein.
In older adults, consuming more animal protein is linked to higher bone mineral density in the spine and whole body, while consuming more vegetable protein shows no consistent link to bone mineral density at these sites.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.