A recent study (published in the American journal, Pediatrics) of 1,239 girls in Harlem, Cincinnati and the San Francisco area revealed that more U.S. girls are starting puberty younger, with many developing breasts and pubic hair as early as seven.
Nearly a quarter of black girls (23.4 percent), 14.9 percent of Hispanic girls and 10.4 percent of white girls develop breasts by the age of seven.
Twenty percent of seven-year-old black girls had pubic hair, as did around 6.5 percent of white and Hispanic girls.
The study found that at age eight, more than four in 10 black girls (42.9 percent) were developing breasts and nearly a third had pubic hair.
Compare these numbers to 1997 statistics, when only five percent of seven-year-old white girls and around 15 percent of black girls of the same age were developing breasts.
Girls who go through puberty earlier have a doubled risk of breast cancer later in life, as well as higher risk of endometrial and ovarian cancer. They are also more likely to become sexually active at an earlier age, and experience low self-esteem, eating problems and depression.
Although the study did not speculate as to what was causing earlier puberty, we know that the following factors are likely to blame:

1. exposure to light at night, which decreases melatonin levels
2. intake of bovine growth hormone found in dairy products
3. high fat diet, particulary from meat, cheese, fried foods, junk food
4. constipation; deficiency of dietary fiber (ideally we should have 3 bowel movements per day and 45 grams of fiber per day)
5. obesity and lack of exercise
6. exposure to chemicals that mimic estrogen, found in plastics (bisphenol-A and phthalates), pesticides, fire retardants, industrial cleansers, dioxin, PCBs, PVC (vinyl), parabens (preservatives in cosmetics), mercury, cadmium, lead

In order to reverse this trend we can:

1. rid our bodies of environmental chemicals before we conceive our children through the intensive use of saunas (150 hours) and a liver and bowel detoxification program so that we do not pass on our accumulated load of environmental estogens on to our children
2. stall puberty in girls by: encouraging 4 hours a week of athletic activity; utilizing a diet high in the protective phytoestrogens such as organic soy and flaxseed to displace the stronger estrogens; reduce consumption of meat and fat to minimize estrogen intake and reabsorption from the intestines; decrease exposure to environmental estrogens or "xenoestrogens"; increase elimination of xenoestrogens through improving liver function and the regular use of saunas; decreasing exposure to light and electromagnetic fields at night to increase melatonin production; prevent obesity in our daughters, since puberty is partially triggered when a certain level of fat is present in a young girl's body
3. encourage higher circulating amounts of estriol (the weak protective estrogen) and lower amounts of estradiol through vegetarian diets high in seaweeds (for iodine), phytoestrogens, fiber and the Brassica family (cabbage, Brussel sprouts, cauliflower, kale etc.) and through normalizing or improving thyroid and liver function