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Dueling Docs: Young Body's Maturing Early. Why?

12/29/2009 12:35 am ET | Updated Nov 17, 2011

The Issue
Girls Reaching Puberty at Younger Ages

The Facts
Have you noticed? Ten-year-old girls don't look like the same care-free, hoola-hoop-playing kids from a generation ago. Rather, many of them seem to have stepped out of a VH1 video with their little waists and developing breasts.

The precocious development of today's young girls has epidemiologists stumped. In the 1800's, the average age of the first menstrual period was 17 years old. That dropped to 14 in 1900 and now it's 12. And today, fully 13% of 7-year-old girls have already begun puberty, according to the Mount Sinai Children's Environmental Health Center in New York. One pediatrician reports that she counsels girls as early as age six about changes in their bodies such as breast budding.

What's going on? A small, but growing chorus of pediatricians and other medical experts suggest that our children's accelerated development has something to do with the world of plastics, pesticides and other environmental "endocrine disruptors" to which kids are exposed. Endocrine disruptors are chemicals that often act like estrogen and interfere with genetic signals, causing changes to the body's finely-tuned hormonal system and potentially resulting in what some would say is a freak show of precocious maturity.

These disruptors are ubiquitous. One recent study by the Center for Disease Control showed 95% of Americans have detectable levels of bisphenol-A (BPA) a now-notorious suspect, found in some baby bottles and water cooler containers. Other possible endocrine disruptors include plasticizers found in cups and in the toys that kids mouth. Then there are the pesticides on the front lawn, the neighbor's lawn and the playground - as well as on most foods lining the supermarket shelves. Since World War II, more than 80,000 chemical compounds have been created and spread into the environment, but only a fraction of them have been studied for their toxic effects on children, according to the Children's Environmental Health Center .

Why worry? Other than what's surely the unsettling appearance of our young girls, medical experts raise concern that early puberty increases the odds of developing breast cancer later in life. The reason: high blood levels of estrogen are a major risk factor for breast cancer. Once a girl starts to menstruate, her estrogen levels rise and don't drop off until menopause. If the arc between the first menses and menopause is lengthened, the risk of breast cancer shoots up.

Is our environment causing a generation of precocious development?

Two doctors debate the issue:
Dr. Alisan Goldfarb, a New York City breast cancer surgeon and Stephen Safe, biochemist and toxicologist with the College of Veterinary Medicine at Texas A&M University.

The Debate

Dr. Alisan Goldfarb:
"The evidence is very compelling that something is going on. What's in the environment is affecting all of us, but it's more obviously affecting our children. Children should not have hormonal activity and the fact is, they are.

We don't know entirely what's causing people to mature earlier than 100 years ago. Is it that we are nutritionally more solid? Increased calories may lead to early maturation. But normal hormonal functioning involves a very complicated feedback system with multiple organs. If you disrupt just one hormone, it can have a cascade of effects.

It's possible that the hormones given to cows and chickens, the pesticides and chemicals put on our fruits and vegetables can all disrupt a child's endocrine system. DDT, was banned, but it's an estrogen and I don't know how to tell an impoverished farmer who can get his hands on a pesticide that would triple his crop not to do so. Legal pesticides can have an estrogen-like effect on the body, too.

Moreover, plastics that are harmless in their original state can mimic hormones as they break down through wear and tear, through washing and heating at high temperatures, and these can have an effect on developing systems in children. All these chemicals that are thought to be harmless might prove harmful to our children if they are looked at as possible endocrine disruptors. This is a brand new area and it's logical to give it scrutiny.

The problem with early menarche is that allows much more time for genetic mistakes to happen and result in breast cancer. Endocrine disruptors could be a big player in this phenomenon.

Actually, recognizing endocrine disruptors provides a glimmer of hope about new ways to prevent breast cancer. Maybe there are substances that we can take out of the environment to protect ourselves. That's really where our money should be spent, instead of on some new drug to treat the end stages of life once the damage has been done."

Dr. Stephen Safe:

"I'm not dismissive but here's the good news: we're living longer and with Obama, we may get better health care.

It's true that lifetime exposure to estrogen is a major risk factor for breast cancer. And early menstruation is lengthening that exposure. Everyone agrees that's a problem. And it's serious. But, while the current hypothesis is that early menarche is due to trace containments out there, these same contaminants are present in other regions of the world where they don't have these problems.

Have you ever been to Japan? I was there five years ago and I watched the young teens get off the school bus. The girls in Japan don't look like our girls. I came back here and it's another planet.

The point is Japanese kids are exposed to the same contaminants we have in North America. They have plastics in Japan, they're burning stuff in the air and there are some very contaminated areas and yet they don't have the early menarche that we see here. I'm not saying our containments are not playing a role, but I'm saying we have to look more critically.

The fact is, anything that disrupts the endocrine system is an endocrine disruptor, not just estrogen. Almost all foods have endocrine disruptors, particularly fruits and vegetables. They've been around forever. Lavender is a proven an endocrine disruptor, but not all kids exposed to lavender go through early menarche.

As for eating organic, it's very difficult to feed populations without pesticides and I'm not so sure there's much difference between organic and not organic anyway. If you are a farmer, be careful. But for the rest of us, we've made a lot of improvement. Most of the pesticides we are using don't hang around on the fruit forever.

I don't know the answer to why there's early menarche in our country. It could be due to pesticides, plasticizers and BPA. I don't know. But it's extremely hard to prove environmental things and I haven't really bought into the idea that the environment is at fault. I don't dismiss the hypothesis but I also caution people that a lot of highly contaminated regions of the world today aren't seeing the problems with their girls that we're seeing with ours."