Dairy product intake and the risk of fragility fractures: important findings from the Nurses’ Health Study cohort

Osteoporosis has traditionally been perceived as a disease of women over 65 years. However, mounting evidence suggests that the risk of impaired bone health and resulting fractures increases around middle age. Fragility fractures result from mid- to low-impact trauma and are indicative of osteoporosis or deteriorations in bone density or microarchitecture.

A prospective study of 103,003 women (mean age: 48 years) from the Nurses’ Health Study cohort measured the association between the risk of the three most common fragility fractures (wrist, hip, or vertebrae) and the intake of dairy products (total dairy, milk, yogurt, and cheese) over a 24-year follow-up period. 

After controlling for potential confounding factors, results indicated: 

• Women who consumed the most dairy (≥2 servings/day) had a 26% lower risk of fragility fractures, compared with those with the lowest dairy intake (<1 serving/week);
  • Each additional serving of dairy was linked to a 6% decrease in fracture risk.
• High milk (≥2 servings/day) and high cheese (≥1 serving/day) intakes were associated with 15% and 11% reductions in fracture risk, respectively; 
  • Each additional serving of milk was linked to a 7% decrease in fragility fracture risk. 
• No association was detected between yogurt intake and fracture risk, though authors mention that this may be due in part to the cohort’s low yogurt intake. 

Importantly, these findings were independent of the intakes of calcium, vitamin D, or protein from non-dairy sources. Effects were detected both in pre- and postmenopausal women. 

• For postmenopausal women, consuming at least 1 serving of dairy per day was associated with 10% lower risk of fracture.

Moreover, separate analyses conducted for wrist and hip fractures revealed similar beneficial associations between dairy intake (total dairy, milk, cheese, yogurt) and fracture at each site. 

Past studies have assessed dairy intake and fracture risk using data from the Nurses’ Health Study. The first, published in 1997, did not observe significant associations between milk products and fracture risk. The authors from the current study mention several potential underlying explanatory factors to contextualize the results of this previous study, namely the relatively young age of the cohort and that they detected few fractures. In contrast, a 2018 study conducted in postmenopausal women linked 2 or more daily servings of milk to a 23% decrease in the risk of hip fractures, with each additional dairy serving corresponding to a 7% risk reduction. 

This recent study conducted in the Nurses’ Health Study cohort has additional strengths, namely that it included three common fragility fracture sites (as opposed to one or two), included premenopausal women as fracture risk is believed to increase around age 40.