printable versionPediatrician's outreach and research are cutting straight to the bones
BY SHAWNA WILLIAMS
Laura Bachrach
Pediatric endocrinology professor Laura Bachrach, MD, isn’t taking any kickbacks from the National Dairy Council. But she is a woman with a mission when it comes to pushing milk.
“Dairy products are critical because 70 percent of the calcium in the American diet comes from dairy,” Bachrach explained. The fact that fractures in childhood have increased dramatically in the past few decades as dairy intake has plummeted is probably not a coincidence, she added.
Not that Bachrach thinks we should look to our bovine friends for a cure-all when it comes to bone health. Realizing the complexity of the issue, she’s attacking it from all sides, studying bone formation in both healthy and sick kids and looking for ways to protect those most at risk for osteoporosis down the road.
She’s motivated by the knowledge that the best time to prevent osteoporosis is when people are young and their bones are still developing. “Many people think osteoporosis is something they don’t have to think about until they’re old,” she said. “The problem is that the window of opportunity to optimize bone health is between birth and age 25, and it’s thought that 60 percent of your risk is how high your peak bone mass is at the end of that window.”
Osteoporosis rates are expected to increase substantially as the population ages and lifespans increase, and Bachrach cites troubling indications that today’s children are squandering their best chance of avoiding the disease. Separate studies carried out in the United States and Scandinavia showed that fracture rates in children increased in the past 40 years by 35 percent in boys and 60 percent in girls and the likely culprit is weak bones, Bachrach said. To reverse this trend, she and others are working to understand how bones develop and how to stem the tide of low bone mass in those most at risk.
Bachrach, who left for a sabbatical a few weeks ago to edit a book on bone density guidelines and to conduct other research, first became interested in healthy bones when she treated girls with anorexia nervosa while assigned to the adolescent medicine division. “I got interested in the status of their bones and found out we lacked any data on them or on what a ‘normal’ bone density was for that age group,” she said. “There were so many questions that had never been addressed.”
To find out what was normal, Bachrach led a longitudinal study in the 1990s in healthy Asian, Hispanic, African-American and Caucasian boys and girls to see how bone density changes over time. She also did other, more descriptive research. “We realized that just talking about bone density is not enough, that there are other aspects involved,” she said. “The changes in the shape and size of bone determine whether the bone’s going to be vulnerable to fracture.”
For example, girls are more likely to get fractures between the ages of 8 and 10, and boys between 11 and 14, perhaps because their bones are growing faster than they can be filled in with mineral, Bachrach said.
She has also studied bone development in children at high risk for bone loss, such as those with anorexia and cystic fibrosis. Along with her work characterizing bones, she also does research in intervention, including a current study on the effect of birth control pills (used as hormone supplements) on the skeletons of elite female college runners.
Despite the prospect of devastating fratures down the road, it can be hard to convince parents or even pediatricians to be concerned with children’s bone health, Bachrach said. “Caregivers for a child with cystic fibrosis may focus on how the child’s lungs are doing, but not how the disease is affecting their bones,” she said. “Even around here, selling pediatricians on the idea of giving Vitamin D supplements to breast-fed babies, which the American Academy of Pediatrics has recommended, can be hard. People think, ‘That doesn’t apply to our family.’”
What’s good for bone health fits nicely with other principles of healthy living, Bachrach said. Physical activities that stress the bones, such as running, jumping or lifting weights, are crucial for bone strength. The calcium, Vitamin D and proteins in milk nourish bones while bulking up muscle at the expense of fat, which in turn lowers the risk for diabetes. Calcium has also been shown to help lower blood pressure. Controlling sodium intake, another tip for building bone, also helps prevent high blood pressure.
Even with these facts on her side—not to mention Britney Spears in a milk mustache—“it’s hard to convince young people to care about this stuff, to care about being physically active, getting enough Vitamin D, getting enough calcium,” Bachrach said. “But if we don’t succeed, then we’re going to miss our window of opportunity