Consumption of Cow's Milk in Early Childhood and Fracture Risk: A Prospective Cohort Study.

Cow's milk is consumed by most North American children, yet the relationships between the volume and fat content of cow's milk consumed and childhood fracture risk are unclear. Our primary objectives in this study were to evaluate whether the volume or fat content of cow's milk consumed at 1-3 years of age was associated with the risk of fracture between 3 and 10 years of age. This was a prospective cohort study of 2,466 children enrolled in Toronto, Ontario, Canada, between 2008 and 2016. The primary exposure was volume of cow's milk consumed between the ages of 1 and 3 years, and the secondary exposure was average percentage of milk fat consumed by each child during the same period. The primary outcome was a parental report of child fracture at ages 3-10 years. In the primary and secondary adjusted analyses, no association between milk volume and fracture risk (adjusted relative risk = 1.04, 95% confidence interval: 0.87, 1.26) or between milk-fat content and fracture risk (adjusted relative risk = 1.05, 95% confidence interval: 0.84, 1.31) was observed. In this study, we did not identify a protective association of early childhood cow's milk volume or fat consumption with fracture risk in later childhood. Future prospective research is needed to understand whether cow's milk is beneficial for fracture prevention through the life course.

Association between noncow milk beverage consumption and childhood height.

Background: Cow milk consumption in childhood has been associated with increased height, which is an important measure of children's growth and development. Many parents are choosing noncow milk beverages such as soy and almond milk because of perceived health benefits. However, noncow milk contains less protein and fat than cow milk and may not have the same effect on height.Objective: We sought to determine whether there is an association between noncow milk consumption and lower height in childhood and assess whether cow milk consumption mediates the relation between noncow milk consumption and height.Design: This was a cross-sectional study of 5034 healthy Canadian children aged 24-72 mo enrolled in the Applied Research Group for Kids cohort. The primary exposure was the volume of noncow milk consumption (number of 250-mL cups per day). The primary outcome was height, which was measured as height-for-age z score. Multivariable linear regression was used to determine the association between noncow milk consumption and height. A mediation analysis was conducted to explore whether cow milk consumption mediated the association between noncow milk consumption and height.Results: There was a dose-dependent association between higher noncow milk consumption and lower height (P < 0.0001). For each daily cup of noncow milk consumed, children were 0.4 cm (95% CI: 0.2, 0.8 cm) shorter. In the mediation analysis, lower cow milk consumption only partially mediated the association between noncow milk consumption and lower height. The height difference for a child aged 3 y consuming 3 cups noncow milk/d relative to 3 cups cow milk/d was 1.5 cm (95% CI: 0.8, 2.0 cm).Conclusions: Noncow milk consumption was associated with lower childhood height. Future research is needed to understand the causal relations between noncow milk consumption and height.