Breast Cancer Fund Report Examines Causes, Effects Of Early Puberty

Main Category: Pediatrics / Children's Health
Also Included In: Women's Health / Gynecology;  Endocrinology;  Breast Cancer
Article Date: 20 Sep 2007 - 11:00 PDT

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A variety of environmental factors could be responsible for early puberty among girls in the U.S., according to a recently released report commissioned by the San Francisco-based Breast Cancer Fund, the Sacramento Bee reports. According to the Bee, U.S. girls as young as age eight are beginning to menstruate, develop breasts, and grow pubic and underarm hair, all of which a few decades ago typically occurred at age 13 or older. Black girls are more likely than other girls to begin puberty at an early age.

The report -- titled "The Falling Age of Puberty in U.S. Girls: What We Know, What We Need To Know" and written by biologist Sandra Steingraber -- examined factors such as obesity, family stress, inactivity, sexual imagery in the media and accidental exposure to chemicals that might prompt early puberty. The report concluded that early puberty can be best described as an "ecological disorder" resulting from different environmental factors.

According to Steingraber, rising childhood obesity has contributed to early puberty because puberty is triggered by leptin, a hormone produced by body fat. According to the Bee, blacks have higher levels of leptin than other groups. In addition, Steingraber found that exposure to household chemicals also contributes to early puberty. The report also linked early puberty with premature birth, low birthweight, consumption of formula as an infant, and excessive television viewing and media use. Steingraber said some of the shift in puberty age can be attributed to evolutionary factors, such as improved nutrition and infectious disease control.

Girls who have their first menstrual period before age 12 have a 50% higher risk for breast cancer than girls who have their first period at age 16, Steingraber said. Marion Kavanaugh-Lynch, an oncologist and director of the California Breast Cancer Research Program, said girls who menstruate early are exposed to higher levels of estrogen, which can cause breast cancer cells to spread. Early puberty also is linked to emotional and social problems, the report found. Steingraber noted that girls who experience early puberty are at "higher risk of depression, early alcohol consumption, substance abuse, early first sexual encounter and unintended pregnancies."

Research, Diagnostic Efforts
According to the Bee, research into the reasons for early puberty is increasing. The Breast Cancer and the Environment Research Center in San Francisco, a federally funded project conducted by scientists at Kaiser Permanente and the University of California-San Francisco, is monitoring environmental exposure in 400 girls over several years to determine predictors of early puberty. In addition, the five-year, state-funded California Environmental Contaminant Biomonitoring Program will measure chemical exposure in blood and urine samples from more than 2,000 California residents, the Bee reports.

Charles Wibbelsman, a pediatrician with Kaiser Permanente and a member of the American Academy of Pediatrics committee on adolescents, said that many pediatricians are adjusting the way that they conduct routine check-ups among girls to identify signs of early puberty. Kavanaugh-Lynch said the report "will advance" research into early puberty and will allow researchers to "think creatively about new areas of study."

The report is available online.

Reprinted with kind permission from http://www.kaisernetwork.org. You can view the entire Kaiser Daily Health Policy Report, search the archives, or sign up for email delivery at http://www.kaisernetwork.org/dailyreports/healthpolicy. The Kaiser Daily Health Policy Report is published for kaisernetwork.org, a free service of The Henry J. Kaiser Family Foundation© 2005 Advisory Board Company and Kaiser Family Foundation. All rights reserved.

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