Dietary Protein Intake And Bone Mineral Density Among Premenopausal Women.

Abstract

In recent years, protein intake has received attention among health professionals and enthusiasts for its use in weight loss and muscle recovery. Protein plays a number of roles in the human body including fluid and electrolyte balance, enzyme production, and cell repair (Thompson & Manore, 2013). It may be less known that dietary protein is needed for the production of collagen which is the foundation for healthy bone production (Heaney, 2007). Calcium is a high quality protein source and has been positively associated with bone health (Winzenberg, Shaw, Fryer, Jones, 2006). PURPOSE: The purpose of this study was to determine if protein intake, independent from calcium in the diet, was correlated with bone mineral density (BMD) among premenopausal women. METHODS: A total of 41 premenopausal women (38.90 ± 7.92 years) completed this study. Anthropometric data were collected and all participants completed a three-day diet record to assess nutrient intake. Physical activity (PA) participation was measured using the Omron HJ-303 pedometer and BMD (g/cm2) was measured at the hips and lumbar spine with a Hologic dual energy x-ray absorptiometry (DEXA) machine. RESULTS: Significant correlations (p < .05) were found between lumbar spine, average femoral neck, and protein (r = .35, p = .030), (r = .39, p = .015), (r = .37, p = .024) after controlling for age, body mass index (BMI), and PA. All of these correlations disappeared once we added calcium as a control variable. CONCLUSIONS: In this sample of pre-menopausal women it seems that the association between calcium intake and lumbar spine, femoral neck, and total hip BMD outweighs any relationship to protein alone. It seems reasonable to conclude that protein intake alone in the diet may not have a strong enough association with bone health. Future research is needed to clarify whether protein intake, independent of calcium, is beneficial for bone health. IRB# 1213-0223