Q. I have two daughters. A friend told me that I should not give them milk because it will prompt them to start puberty early. Is this true?
A. Over the past several decades, parents have started noticing signs of puberty, such as body odor and breast buds, at earlier ages. In the United States, the average age of menarche (the first period) has drifted down slightly to 12.5 years from 12.75 years in 1970. No one is sure why.
Some speculate that the artificial growth hormone given to cows to increase milk production – recombinant bovine growth hormone or rBGH – is the cause. However, milk intake does not affect puberty.
First, the amount of rBGH that crosses into a cow’s milk is negligible and has to be broken down and denatured. On top of that, growth hormones are not biologically active when ingested because they are broken down in the stomach. They would have to be injected. Also, a 2012 Chinese study looked at 7,500 children in Hong Kong and found no link between milk consumption and puberty onset.
So why are children having earlier puberty? Childhood obesity can advance pubertal changes, and childhood obesity is on the rise. One of the best things parents can do for their child’s health is encourage a healthy diet and active lifestyle leading to a healthy weight. Low fat milk is an excellent source of calcium, vitamin D, choline and protein.
More studies need to be done to really look at pubertal changes in today’s children. In the meantime, children should continue to enjoy three servings of dairy a day.
Rhonda Patt is a pediatrician with Charlotte Pediatric Clinic. Email firstname.lastname@example.org; put “pediatrician” in the subject line.