Protein intake and fracture risk in elderly people: a case-control study

Clin Nutr. 2012 Jun;31(3):391-5. doi: 10.1016/j.clnu.2011.11.016. Epub 2011 Dec 17.


Background & aims: We investigated whether protein intake (PI) is related to osteoporotic fractures (OP) in the elderly by analyzing vegetable protein intake (VPI), animal protein intake (API), and animal/vegetable protein intake ratio (AVR) and by calcium intake (CaI).

Methods: A 1:1 matched by age and sex case-control study with 167 cases was carried out at the Hospital of Jaen (Spain). Cases were patients aged ≥65 years with a low-energy fracture. Controls were people without previous fractures. Diet was assessed by a food frequency questionnaire. Multivariable analyses were fitted using analysis of covariance (for comparison of adjusted means) and conditional logistic regression (estimating adjusted odds ratios [ORs]).

Results: The control-group showed a higher API (p = 0.046) even when CaI was <800 mg/day (p = 0.041). ORs for AVR were 0.68 (0.38-1.19) and 0.38 (0.15-0.98), respectively with a p for trend = 0.046. A PI<15% of the total energy intake showed an OR of 2.86 (1.10-7.43).

Conclusions: Patients with fracture history have lower API suggesting that high API reduce the occurrence of OP in elderly even if CaI is <800 mg/day. A PI<15% of total calories were associated with an increased risk of OP in elderly.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Algorithms
  • Calcium, Dietary / administration & dosage
  • Case-Control Studies
  • Diet, Mediterranean* / ethnology
  • Diet, Protein-Restricted / adverse effects
  • Diet, Protein-Restricted / ethnology
  • Dietary Proteins / administration & dosage*
  • Energy Intake / ethnology
  • Female
  • Humans
  • Male
  • Odds Ratio
  • Osteoporotic Fractures / epidemiology
  • Osteoporotic Fractures / ethnology
  • Osteoporotic Fractures / etiology*
  • Osteoporotic Fractures / prevention & control
  • Plant Proteins, Dietary / administration & dosage
  • Risk
  • Spain / epidemiology
  • Surveys and Questionnaires


  • Calcium, Dietary
  • Dietary Proteins
  • Plant Proteins, Dietary