Apr 122011

Worthwhile reading today on page 1 of USA Today. The cover story is titled ‘Girls hit puberty earlier than ever, and doctors aren’t sure why.’

Here’s a brief excerpt with the grim stats:

About 15% of American girls now begin puberty by age 7, according to a study of 1,239 girls published last year in Pediatrics. One in 10 white girls begin developing breasts by that age — twice the rate seen in a 1997 study. Among black girls, such as Laila, 23% hit puberty by age 7.

“Over the last 30 years, we’ve shortened the childhood of girls by about a year and a half,” says Sandra Steingraber, author of a 2007 report on early puberty for the Breast Cancer Fund, an advocacy group. “That’s not good.”

I give this article credit for hinting at the reasons why puberty is starting earlier. It addresses rising rates of childhood obesity; endocrine disruptors such as pesticides, phthalates in water bottles, and BPA in cans; and reduction of melatonin levels triggered by overexposure to computer and TV screens. It also mentions stress and premature birth rates (up 18% since 1990, according to the article) as possible causes. What it doesn’t mention — and what I rarely see in articles of this type — is an acknowledgment that many of the problems and diseases of modern life are interlinked, so early puberty cannot really be viewed in isolation.

One indication that the problem is modern life and not genetics is mentioned in the article:

Studies consistently show that black girls in the USA go into puberty earlier than whites, suggesting a possible genetic difference. Yet Steingraber notes that, 100 years ago, black girls actually matured later than whites. And she notes that black girls in Africa enter puberty much later than those in the USA, even when their nutrition and family incomes are comparable.

Since we can’t turn back the clock to the year 1900, how can we fight back against the onslaught of contaminated food, water, and environmental surroundings? I discuss some ideas in the 10 Changes section in relation to general health, but this is what I would do if I had a daughter:

1. Choose organic dairy. Conventional dairy products may contain recombinant bovine growth hormone (rBGH) and/or recombinant bovine somatotropin (rBST). These hormones stimulate increased milk production by cows, but that milk also contains higher than normal levels of insulin-like growth factor 1 (IGF-1). What is IGF-1? A trigger of puberty in mice, according to recent research from Johns Hopkins. 1 I look forward to the human studies — in the meantime, organic milk is unlikely to contain such high levels of IGF-1. Plus, it is free of antibiotic residues, and the cows cannot be fed genetically modified corn. Honestly, I might go easy on dairy in general, since most mammals in nature don’t consume it after they’re weaned.

2. Banish high-fructose corn syrup. Since obesity is a possible contributor to early puberty, I would seek out products unlikely to promote obesity. That means real, unrefined food — organic fruits, vegetables, nuts, seeds, lean meats and eggs, beans, and whole grains, ideally speaking. If that were not entirely possible, I would at least avoid likely contributors to the obesity epidemic, such as HFCS. 2

3. Dump the plastic water bottles and canned foods. I would use stainless steel water bottles (less breakable than glass) and fill them with filtered tap water, using a high-quality reverse osmosis or combination filtration system (such as Aquasana). And I would seek out food packaged in BPA-free cans, glass jars, or bags.

4. Encourage outdoors time. I would make sure the day included some active time outside in real sunlight. Humans aren’t built to live indoors 24/7.

5. Enforce screen-off time. I would install Flux on all computers. I would set the computer to shut down automatically about an hour before bedtime. I would turn off the television about an hour before bedtime. I would encourage the reading of old-fashioned paper books — not on-screen books — in that last hour before sleep.