Dietary acid load in early life and bone health in childhood: the Generation R Study

Abstract

Dietary contribution to acid-base balance in early life may influence subsequent bone mineralization. Previous studies reported inconsistent results regarding the associations between dietary acid load and bone mass. We examined the associations of dietary acid load in early life with bone health in childhood. In a prospective, multiethnic, population-based cohort study of 2850 children, we estimated dietary acid load as dietary potential renal acid load (dPRAL), based on dietary intakes of calcium, magnesium, phosphorus, potassium, and protein, and as a protein intake to potassium intake ratio (Pro:K) at 1 y of age and in a subgroup at 2 y of age : Bone mineral density, bone mineral content (BMC), area-adjusted BMC, and bone area were assessed by dual-energy X-ray absorptiometry at the median age of 6 y. Data were analyzed by using multivariable linear regression models. After adjusting for relevant maternal and child factors, dietary acid load estimated as either dPRAL or Pro:K ratio was not consistently associated with childhood bone health. Associations did not differ by sex, ethnicity, weight status, or vitamin D supplementation. Only in those children with high protein intake in our population (i.e., >42 g/d), a 1-unit increase in dPRAL (mEq/d) was inversely associated with BMC (difference: -0.32 g; 95% CI: -0.64, -0.01 g). Dietary acid load in early life was not consistently associated with bone health in childhood. Further research is needed to explore the extent to which dietary acid load in later childhood may affect current and future bone health.