December 29, 2014

New book explains early puberty in girls

Authors hope new book will help people thrive.

By Elizabeth Schainbaum, Kaiser Permanente Northern California

The next generation seems to be growing up faster — measured by the growing number of girls who are entering puberty in elementary school.

Louise Greenspan, MD, a pediatric endocrinologist at Kaiser Permanente San Francisco, who works with the Kaiser Permanente Division of Research, has been studying girls’ puberty in Kaiser Permanente Northern California members. This research uncovered that girls were entering puberty earlier than previously thought — 15 percent at age 7, and 27 percent by age 8. Just a generation ago, fewer than 5 percent started puberty at age 8.

Because of the strong interest in early puberty research, Dr. Greenspan and Julianna Deardorff, PhD, a psychologist at the University of California, Berkeley, collaborated on a book on the topic for a general audience. Deardorff offered the psychological perspective.

Image of the cover of a book called The New Puberty, image is of two girls from behind in black and whiteThe two go beyond the Kaiser Permanente research and analyze other research on puberty for their recently published book, “ The New Puberty: How to Navigate Early Development in Today’s Girls.”

Dr. Greenspan discussed the causes for early puberty, its consequences and what people can do to prevent and manage it.

Why should we pay attention to early puberty?

Let’s first define puberty in girls. Many people think it’s when menstruation begins, but it starts when there’s breast development and pubic hair.

Early puberty has consequences because it’s not just a physical transformation. It’s deeply psychological, too, and an 8-year-old’s brain can’t handle some of the changes as well as a 13-year-old would. Research shows that girls who go into puberty earlier are at higher risk for behavioral problems as well as long-term health challenges, such as obesity, depression, eating disorders and even cancer.

That said, early puberty doesn’t necessarily lead to these consequences. Parents and adults can guide girls through it, and we wrote the book with this in mind.

Why are more girls going into puberty earlier?

There are three main causes: obesity or being overweight, exposure to chemicals and stress, usually stemming from unstable homes, socio-economic troubles or being exposed to violence.

Chemicals, such as BPAs (bisphenol A), pesticides, flame retardants or antibiotics in food, can mimic hormones. The hormonal pathway we are concerned about is estrogen. Since we are all exposed to so many chemicals, the challenge is to isolate the culprit.

Also, decades of studies have shown that girls in unpredictable environments with low emotional warmth tend to go into puberty earlier. The most common explanation is an evolutionary one, where the body feels it may have to reproduce sooner.

Out of all three of these factors, the one that probably has the greatest impact is weight — the rise in early puberty has mirrored the obesity epidemic. Fat tissue is a potent hormonal organ and converts other hormones into estrogen and estrogen-like substances. The more fat you have, the higher the estrogen levels, and that higher estrogen level leads to early puberty.

What’s your recommendation to parents who have a girl going into puberty early?

Educate yourself on what puberty is and how to talk to your children about it. Our book offers tools on what to ask doctors, how to help kids handle the emotions that accompany puberty and ways to discuss the risks and changes.

It also offers practical tips that could prevent early puberty. For example, we recommend that children eat soy — whole foods such as edamame or tofu — because it probably trains the body to resist estrogen and may lead to later puberty. We also discuss ways to reduce chemical exposure. For example, even if we don’t know plastics are unsafe, we can use glass and stainless steel because we know that they are safe.

There are lots we can do to prevent or mitigate early puberty. We want people to feel empowered after reading our book.