ARS | Publication request: Clusters of Dietary Protein and Relation to Bone Mineral Density (BMD) in Men and Women of the Framingham Offspring Study

Submitted to: American Society for Bone and Mineral Research
Publication Type: Abstract Only
Publication Acceptance Date: May 1, 2007
Publication Date: September 16, 2007
Citation: Tucker, K., Qiao, N., Mclennan, C.E., Broe, K.B., Mclean, R.R., Kiel, D.P., Cupples, L.A., Hannan, M.T. 2007. Clusters of Dietary Protein and Relation to Bone Mineral Density (BMD) in Men and Women of the Framingham Offspring Study. In: American Society for Bone and Mineral Research Annual Meeting, Sept.16-19, 2007, Honolulu, HI. W267, pS429.

Technical Abstract: Several studies have shown that dietary protein intake may be protective of BMD rather than contributing to calcium loss. We have previously shown a positive relation between BMD and protein in the elderly Framingham Original Cohort. As protein-rich foods are also rich sources of other nutrients, we now further examined this relation by food source of dietary protein in the primarily middle-aged members of the Framingham Offspring cohort. We evaluated the cross-sectional relation between food sources of protein and BMD in 2919 Framingham Offspring Study participants (mean age 61y) with BMD at femoral neck (FN), trochanter (TR) and lumbar spine (LS) obtained by Lunar DPX-L in 1996-2000. Dietary intakes were estimated using the Willett 126-item food frequency questionnaire and we used cluster analysis to classify individuals into 5 groups determined by major source of protein (table). Multivariable linear regression was used to compare least-squares adjusted mean BMD among protein clusters, adjusting for: total energy, sex, age, weight, height, smoking, total protein intake, calcium, vitamin D, physical activity, caffeine, alcohol and in women, menopause status and estrogen use. We further adjusted for fruit and vegetable servings, an indicator of overall healthy diet also associated with higher BMD. The dietary cluster for which the primary source of protein was low-fat milk had significantly greater FN and TR BMD than the other clusters (this cluster also tended to have greater LS BMD, p<0.10). Associations remained after further adjustment for fruit and vegetable servings. In summary, increased protein intake continues to be associated with higher BMD, but a dietary pattern with primary protein sources of low-fat milk and breakfast cereal appears to have the greatest effect, even after adjusting for calcium, vitamin D and fruit and vegetable intakes. These findings show that the beneficial effect of protein on BMD may depend upon the source from which protein is obtained.