Childhood dairy intake may improve adolescent bone health

Dairy is recognised as a key component of a healthy, balanced diet. However, until recently it was unclear how long-term dairy intake contributes to the many aspects of bone health in children, including bone density, bone mineral content, and bone area. A new study soon to be published in The Journal of Pediatrics investigates the effect of childhood dairy intake on adolescent bone health.

Dr. Lynn Moore and colleagues from Boston University School of Medicine analysed data from the Framingham Children's Study in an effort to understand the relationship between childhood dairy intake and adolescent bone health. The researchers gathered information from 106 children, 3 to 5 years of age at the beginning of the study, over a 12-year period. The families enrolled in the study were given food diaries to complete for the child and were asked to record everything the child ate and drank for several days each year.

The researchers used these diaries, along with information from the United States Department of Agriculture, to calculate the children's average daily intake of dairy and other foods. At the end of the 12-year period, the authors assessed the bone health of the now adolescent study participants. They found that the adolescents who had consumed 2 or more servings of dairy per day as children had higher levels of bone mineral content and bone density. Even after adjusting for factors that affect normal bone development, including the child's growth, body size, and activity level, the authors found that these adolescents' average bone mineral content was 175 grams higher than the adolescents who had consumed less than 2 servings of dairy per day.

The researchers also evaluated the combined effects of dairy and other foods consumed by the study participants. According to Dr. Moore, "Children who consumed 2 or more servings of dairy and 4 ounces of meat or other non-dairy protein had bone mineral contents over 300 grams higher than those children with lower intakes of both dairy and other proteins." The study highlights the importance of dairy intake throughout childhood, and Dr. Moore points out that "dairy is a key source of proteins, calcium, and other micronutrients including phosphorus and vitamin D." Parents can promote healthy bone development during adolescence by making dairy a regular part of their child's diet.

(Source: Journal of Pediatrics: Elsevier: August 2008)