The average age of a girl's first period is around 12. The research included data from over 7,500 girls. Researchers are interested in the reason for the difference in the onset of menstruation because women who get breast cancer are more likely to have begun menstruating before age eleven.

Finding possible causes for breast cancer is important due to the fact that (excluding cancers of the skin) breast cancer is the most common form of cancer in women in the United States.

In this issue, much is unknown and controversial. Researchers are asking questions about these trends that are, as of yet, largely unanswered. Researchers suggest cultural dietary changes or environmental agents as possible role-players, but there's no consensus on the issue.

Pediatrics October 2002; 110: 43

National Alliance of Breast Cancer Organizations

Dr. Mercola's Comments:

This is not a good sign. This is most likely a reflection of the tremendous exposure we have all had to chemicals in our environment. Theo Colburn wrote an excellent book on this topic: Our Stolen Future. There is also a website that follows the emerging science and debates about new advances in toxicology that challenge basic assumptions about which chemicals are safe and what exposures are tolerable.

It is likely that PCBs and DDE (a breakdown product of the pesticide DDT) may indeed be associated with early sexual development in girls. Both DDE and PCBs are known to mimic, or interfere with, sex hormones.

Early puberty is really only the tip of the iceberg as the same chemical exposures that cause this can lead to increased infertility and breast cancer rates.

Related Articles:

Chemical Contamination Linked to Early Puberty

Girls Are Reaching Puberty Early