Dairy = Higher Spine Bone Density in Men, Not Women

A team of international researchers has just published work titled, “Higher Dairy Food Intake Is Associated With Higher Spine Quantitative Computed Tomography (QCT) Bone Measures in the Framingham Study for Men But Not Women.”

The study appears in the March 30, 2018 edition of the Journal of Bone and Mineral Research.

Shivani Sahni, Ph.D., assistant professor of Medicine at Harvard Medical School and co-author on the study, told OTW, “We have previously shown that higher dairy food intake is associated with lower bone loss especially among those who used vitamin D supplements.”

“Older adults tend to be deficient in vitamin D as recommended intakes are difficult to achieve without fortified foods (such as dairy) or supplements. Vitamin D stimulates calcium absorption, which is beneficial for building bones.”

“However, it is unclear if the effect of vitamin D on calcium absorption is substantial enough to translate into beneficial effects on bone. Therefore, in the current study we wanted to determine the association of dairy food intake with bone health and whether these associations would be modified by vitamin D status.”

The authors wrote, “Participants were 1,522 men and 1,104 women (aged 32 to 81 years, mean 50 years [men]; 55 years [women]) from the Framingham Heart Study with measures of dairy food intake (servings/wk) from a food‐frequency questionnaire, volumetric BMD [bone mineral density], cross‐sectional area, and estimated vertebral compressive strength and 25‐OH D (radioimmunoassay).”

“The majority of the previous studies on this topic used areal bone mineral density from DXA and focused largely on milk intake. However, we have novel bone measures such as quantitative computed tomography (QCT) available in large epidemiological studies, which are unique because they provide information on bone geometry and compartment-specific bone density that are key determinants of bone strength.”

“Therefore, we used these measures in the current study. Additionally, we determined whether vitamin D status modified the association of dairy foods intake upon bone health using serum 25-hydroxy vitamin D concentrations, which is a better marker of vitamin D status compared with dietary intake or supplemental intake. In addition to milk, we also examined other dairy foods such as cheese and yogurt.”

“In men, higher intakes of dairy foods such as milk, yogurt and cheese are associated with higher volumetric bone mineral density and vertebral strength at the spine. Dairy intake seems to be most beneficial for men over the age of 50 and continued to have positive associations irrespective of serum vitamin D status. While we did not see any association in women, it is important to note that women in this study were calcium replete because their calcium intake was ~1200 mg/d.”

“The results of this study highlight the beneficial role of a combination of dairy foods upon bone health. The recommendation from the Institute of Medicine for dairy food intake is 3 servings per day, which would provide the essential bone beneficial nutrients such as calcium, vitamin D (from fortified dairy foods), protein and phosphorus.”

“It is important to assess the diet of a patient and examine vitamin D status as well. Nutrition studies have shown that higher intake of calcium, vitamin D, protein and specific antioxidants such as vitamin C and carotenoids are linked with better bone measures and reduced fracture risk. Optimum intake of dairy foods can provide some of these key nutrients.”

Laura van Dongen, a Ph.D. student at Wageningen University and Research Centre in the Netherlands, was also a contributing author on this work.