title: Bone Mineral Density and Protein-Derived Food Clusters from the Framingham Offspring Study.
abstract: BACKGROUND
  Dietary protein is beneficial to bone health; however, dietary patterns of protein intake and their relationship with bone mineral density (BMD) have not been evaluated.
  
  
  OBJECTIVE
  To examine the relationship of dietary protein food clusters with BMD at the femoral neck, trochanter, total femur, and lumbar spine among middle-aged and older men and women.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  Two thousand seven hundred fifty-eight community-dwelling individuals from the Framingham Offspring Study.
  
  
  METHODS
  BMD was measured by Lunar DPX-L (Lunar Radiation Corporation) in 1996-2001. Dietary intakes were estimated using the Willett food frequency questionnaire in either 1995-1998 or 1998-2001, and the exam closest to a participant's BMD measurement was used. Cluster analysis (FASTCLUS procedure, k-means method) was used to classify participants into groups, determined by major sources of protein. Generalized linear regression was used to compare adjusted least-squares mean BMD across protein food clusters for all pairwise comparisons.
  
  
  RESULTS
  From 2,758 participants (44% men; mean age 61±9 years, range=29 to 86 years), five protein food clusters were identified (chicken, fish, processed foods, red meat, and low-fat milk). Three of these food clusters showed associations with BMD. The red meat protein food cluster presented with significantly lower femoral neck BMD compared with the low-fat milk cluster (red meat 0.898±0.005 g/cm(2) vs low-fat milk 0.919±0.007 g/cm(2); P=0.04). Further, the processed foods protein cluster presented with significantly lower femoral neck BMD compared with the low-fat milk cluster (processed foods 0.897±0.004 g/cm(2) vs low-fat milk 0.919±0.007 g/cm(2); P=0.02). A similar, yet nonsignificant, trend was observed for other BMD sites examined.
  
  
  CONCLUSIONS
  Diets with the greatest proportion of protein intake from red meat and processed foods may not be as beneficial to the skeleton compared with dietary patterns where the highest proportion of protein is derived from low-fat milk.
authors.forename: Kelsey M
authors.initials: KM
authors.lastname: Mangano
authors.forename: Shivani
authors.initials: S
authors.lastname: Sahni
authors.forename: Douglas P
authors.initials: DP
authors.lastname: Kiel
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Tucker
authors.forename: Alyssa B
authors.initials: AB
authors.lastname: Dufour
authors.forename: Marian T
authors.initials: MT
authors.lastname: Hannan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D015992:Body Mass Index; D015519:Bone Density; D002136:Calcium, Dietary / Q000008:administration & dosage; D002645:Chickens; D003430:Cross-Sectional Studies; D004032:Diet; D004034:Diet Surveys; D004044:Dietary Proteins / Q000008:administration & dosage*; D019587:Dietary Supplements; D002149:Energy Intake; D005260:Female; D005272:Femur Neck / Q000378:metabolism; D005399:Fishes; D006801:Humans; D008297:Male; D008404:Massachusetts; D008460:Meat; D008875:Middle Aged; D008892:Milk; D009043:Motor Activity; D015596:Nutrition Assessment; D000069466:Red Meat; D017747:Seafood; D011795:Surveys and Questionnaires; D014807:Vitamin D / Q000008:administration & dosage
chemical_list: D002136:Calcium, Dietary; D004044:Dietary Proteins; D014807:Vitamin D
keywords: Aging; Bone mineral density; Cohort; Dietary patterns; Dietary protein