Even after teenagers attain their adult height, their bones are still growing. This period in adolescents’ late teens is a prime window of opportunity to reinforce the importance of good diet and physical activity for lifelong health, according to researchers.

“We often think of a child’s growth largely with respect to height, but overall bone development is also important,” says Shana E. McCormack, MD, a pediatric researcher at Children’s Hospital of Philadelphia (CHOP).

“This study shows that roughly 10% of bone mass continues to accumulate after a teenager reaches his or her adult height,” adds McCormack, lead author of a study published recently in JAMA Pediatrics.

In the study, she, as well as researchers from Ohio, Nebraska, New York, California, and the National Institutes of Health (NIH), analyzed a racially diverse, multi-center sample from the NIH-funded Bone Mineral Density in Childhood Study (BMDCS).

The BMDCS study included sophisticated bone and growth measurements during annual visits for up to seven years in over 2000 healthy children, adolescents and young during 2002 to 2010, according to a media release from Children’s Hospital of Philadelphia.

Babette S. Zemel, PhD, principal investigator of the BMDCS study, notes in the release that the current study found that bone growth is site-specific, with bone mineral density developing at different rates in different parts of the skeleton.

“We also showed that growth events peak earlier in African-American adolescents than in non-African-American adolescents. When healthcare providers interpret data such as bone density in their patients, they should take into account these patterns in growth trajectories,” she adds.

In addition, the study suggests that height growth far outpaces gains in bone mineral prior to adolescence, which may explain the high fracture rates among children and adolescents. Approximately 30% to 50% of children will experience at least one fracture prior to adulthood. The “lag” in bone mineral accrual is compensated for after height growth is complete.

The authors conclude that late adolescence offers clinicians a window of opportunity to intervene with their patients, the release explains.

“Late adolescence is when some teenagers adopt risky behaviors, such as smoking and alcohol use, worse dietary choices and decreased physical activity, all of which can impair bone development,” McCormack says “This period is a time for parents and caregivers to encourage healthier behaviors, such as better diets and more physical activity.”

“We’ve known for a long time that maximizing bone health in childhood and adolescence protects people from osteoporosis later in life,” Zemel concludes. “This study reinforces that understanding, and suggests that late adolescence may be an under-recognized period to intervene in this important area of public health.”

[Source(s): Children’s Hospital of Philadelphia, Science Daily]