A healthy, balanced diet is important for overall good health, but certain nutrients, such as protein, calcium, vitamin D, potassium, phosphorus, magnesium, and zinc, are particularly important for healthy bones.
Inadequate intakes of these nutrients increase the risk of bone loss and subsequent risk of osteoporosis, a condition characterized by low bone mineral density. Because dairy foods provide more of these bone-benefiting nutrients per calorie than any other food, consumption of dairy foods has been shown to be positively related to bone mineral density and reduced bone loss over time among a narrow sample of non-Hispanic whites. Although Puerto Rican adults (the second-highest represented subgroup of Hispanics in the United States) have a higher prevalence of osteoporosis and vitamin D deficiency than non-Hispanic whites, the impact of dietary choices on bone health in this population is poorly understood. Findings from a recent study conducted by Drs. Kelsey Mangano, Katherine Tucker, and Sabrina Noel (University of Massachusetts-Lowell) and published in the January 2019 issue of The Journal of Nutrition, reveal a unique dietary pattern that may detrimentally affect bone health.
To test their hypothesis, a total of 904 participants from the Boston Puerto Rican Osteoporosis Study provided diet information using a culturally tailored food-frequency questionnaire. For this study, dairy food groups included milk, yogurt, fluid dairy (milk + yogurt), cheese, cream and dessert dairy. Bone mineral density was measured using dual-energy X-ray absorptiometry, and vitamin D status was defined as sufficient or insufficient using a standard blood test.
The researchers found that higher intakes of modified dairy (milk + yogurt + cheese) and milk alone were significantly associated with higher bone mineral density. However, when compared by vitamin D status, total dairy, fluid dairy (milk + yogurt), and milk intake were significantly related to higher bone mineral density only among those with vitamin D sufficiency. Calcium and vitamin D intakes from all foods were lower than in the Dietary Guidelines, whereas protein intakes were higher compared with other adult populations. The scientists concluded that this unique dietary pattern may detrimentally affect bone health, because dietary protein intakes appear to be protective only under conditions of adequate calcium intake. Potential interventions to improve bone health should include dairy products in combination with public health messages to improve vitamin D sufficiency. Future studies should confirm these findings as well as assess culturally acceptable strategies to improve bone health among Hispanic adults.
Reference Mangano KM, Noel SE, Sahni S, Tucker KL. Higher Dairy Intakes Are Associated with Higher Bone Mineral Density among Adults with Sufficient Vitamin D Status: Results from the Boston Puerto Rican Osteoporosis Study. Journal of Nutrition. 2019; In Press.