Aging and Chronic Disease
Objectives : Previous studies reported that dairy foods are associated with higher areal bone mineral density (BMD) in older adults. However, data on bone strength and bone microarchitecture are lacking. The objective of this study was to determine the association of milk, yogurt, cheese, cream, milk+yogurt and milk+yogurt+cheese intakes with high resolution peripheral quantitative computed tomography (HR-pQCT) measures of bone in older adults from the Framingham Offspring study.
Methods : This cross-sectional study included 532 men and 694 women (aged 32-81y, mean 64y) with measures of dairy food intake (servings/wk.) from a food frequency questionnaire. Cortical and trabecular BMD and microarchitecture at the distal tibia and radius were measured using HR-pQCT. We focused on five bone parameters: 1) Bone strength assessed via failure load from micro–finite element analysis, 2) Two cortical bone measures: cortical BMD and cortical thickness; and 3) Two trabecular bone measures: trabecular bone density and trabecular number. Sex-combined and sex-specific multivariable linear regression was used to estimate the association of dairy food intake (energy adjusted) with each bone measure adjusting for covariates (sex, age, height, weight, current smoking, energy intake, calcium supplement use, vitamin D supplement use, physical activity and multivitamin use).
Results : Over 90% of the participants consumed the recommended ≥3 servings of dairy per day. Mean milk intake±SD was 5.5 servings/week in both men and women. In sex combined analyses, only cheese intake was associated with cortical BMD at the radius and tibia (Table). None of the other dairy foods were significantly associated with any of the bone measures. In sex-stratified analysis higher cheese intake was associated with lower cortical BMD at the radius and tibia in women alone (radius: β= -9.61±2.73, P=0.001, tibia: β= -9.41±3.10, P=0.001). In men, higher cream intake was associated with higher trabecular number (radius: β= 0.021±0.011, P=0.02, tibia: β= 0.024±0.012, P=0.05). Higher yogurt intake was also associated with higher trabecular volumetric BMD at the tibia in men alone (tibia: β= 4.86±2.00, P=0.02).
Conclusions : In this cohort of primarily healthy older men and women with high dairy food consumption, specific dairy foods seem to be more beneficial in men than women. Negative associations for cheese intake and cortical BMD in women should be further confirmed in longitudinal studies.
Funding Sources :
NIH AR # 053205; FHS N01-HC-25195 R01 AR/AG 41398 and unrestricted institutional research grant from Dairy Management Inc.