Types of dairy foods and risk of fragility fracture in the nurses' health study cohort

Authors: MENGJIE, YUAN - Boston University Medical School; HU, FRANK - Harvard School Of Public Health; YANPING, LI - Harvard School Of Public Health; CABRAL, HOWARD - Boston University School Of Public Health; DAS, SAI KRUPA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; DEENEY, JUDE - Boston University Medical School; ZHOU, XINYI - Boston University Medical School; PAIK, JULIE - Brigham & Women'S Hospital; MOORE, LYNN - Boston University Medical School

Submitted to: The American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/21/2023
Publication Date: 9/28/2023
Citation: Mengjie, Y., Hu, F.B., Yanping, L., Cabral, H., Das, S., Deeney, J.T., Zhou, X., Paik, J.M., Moore, L.L. 2023. Types of dairy foods and risk of fragility fracture in the nurses' health study cohort. The American Journal of Clinical Nutrition. https://doi.org/10.1016/j.ajcnut.2023.09.015.
DOI: https://doi.org/10.1016/j.ajcnut.2023.09.015

Interpretive Summary: Bone fractures, often caused by low-impact injuries, are linked to fragile bones and are more common in middle-aged/older women compared to men. This study aimed to investigate the association between total dairy consumption as well as individual dairy products (yogurt, cheese, and milk) on risk of fracture (of the wrist, hip, or vertebrae) in older/middle aged women. 103,003 women with an average age of 48 years old reported their dietary dairy intake and bone fracture history. Findings show that dairy consumption, particularly milk and cheese, may reduce fracture risk in women, including premenopausal individuals, when comparing highest to lowest intake of these dairy sources. These findings expand on previous research in the Nurses' Health Study and suggest that dairy intake can be a simple way to lower fracture risk in women and can inform preventative measures for at risk premenopausal women after going through menopause.

Technical Abstract: Background: Fragility fractures present enormous health challenges for women. Dairy products provide many bone-beneficial nutrients, such as calcium and vitamin D. Individual dairy foods may exert different effects on bone health. Objectives: The aim of this study was to investigate the associations between total dairy, yogurt, milk, and cheese and fragility fracture risk among females in the prospective Nurses' Health Study (NHS) conducted in the United States. Methods: In the current analysis, 103,003 females with mean age of 48 y were followed from 1980-2004. Proportional hazards models were used to estimate risk of first fracture (of the wrist, hip, or vertebrae) by intakes of dairy foods (total dairy, milk, yogurt, or cheese) obtained from a food frequency questionnaire. Fractures that were caused by high-trauma events were not included. We relied on self-reported data for wrist and hip fractures whereas for vertebral fractures, medical records were used to confirm cases. Results: A total of 5495 incident fracture cases were documented during follow-up. After controlling for relevant confounding variables, consumption of = 2 servings/d of total dairy (compared with <1 serving/d) was associated with lower fracture risk (hazard ratio [HR]: 0.74; 95% confidence interval [CI]: 0.61, 0.89). More than 2 servings of milk per day (compared with <1 serving/d) were associated with a lower fracture risk (HR: 0.85; 95% CI: 0.77, 0.94). Intakes of calcium, vitamin D, and protein from nondairy sources did not modify the effects of total dairy or milk on fracture risk. There was no association between yogurt intake and fracture risk. Intake of cheese (=1 servings/d compared with <1 serving/wk) was weakly associated with lower fracture risk (HR: 0.89; 95% CI: 0.79, 0.99). Conclusions: Higher total dairy, milk, and cheese intakes are associated with lower risks of fracture in females in the NHS.