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Is Humanity Regressing Below the Apes? |
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Puberty Coming Earlier
An epidemic of early puberty is hitting young girls in the U.S. Among Caucasian girls in the U.S. today, 1 in every 7 starts to develop breasts or pubic hair by age 8, and among African American girls in the U.S., the figure is nearly 1 out of every 2.
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"Young girls [in the 5-to-10-year-old range] with breasts or pubic hair - we encounter this every day we're in clinic," says Dr. Michael Freemark, chief of pediatric endocrinology at Duke University Medical Center in Durham, N.C. Chemicals in the environment, hormones in cow's milk and beef, and obesity are being investigated as the cause(s).
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Epidemic of Early Puberty Hitting U.S. Girls - "TIME", Oct. 30. 2000
In retrospect, pediatricians and psychologists say, there have been hints for the past decade or so that something strange was going on. But it wasn't until 1997, when Marcia Herman-Giddens, now an adjunct professor at the University of North Carolina School of Public Health, published a now-famous paper in the journal Pediatrics. [ continued below ]
Original Herman-Giddens et al. Article:
Secondary sexual characteristics and menses in young girls seen in office practice: a study from the pediatric research in office settings network. Pediatrics 99(4):505-512, 1997.
Herman-Giddens, ME, EJ Slora, RC Wasserman, CJ Bourdony, MV Bhapkar, GG Koch and CM Hasemeir. 1997.
Herman-Giddens et al. analyze data rating stages of sexual maturation in 17,077 girls ages 3 through 12 in the United States. Of the sample, 9.6% were African-American and 90.4% were white.
Even at the age of 3, the youngest in the study, 3% of African-American girls and 1% of white girls showed breast and/or pubic hair development, with proportions increasing to 27.2% and 6.7%, respectively, at 7 years of age. At age 8 the percentages are 48.3% and 14.7%.
Prevalence of breast development at Tanner stage 2 or greater by age and race. Prevalence of pubic hair development at Tanner stage 2 or greater by age and race.
The mean age for onset of breast development was 8.87 years for African-American girls and 9.96 years for white girls; for onset of pubic hair development mean ages were 8.78 years and 10.51 years, respectively.
Herman-Giddens et al. conclude that girls in the United States are developing pubertal characteristics earlier than the age suggested in standard pediatric textbooks and earlier than previous studies. They are unable, however, to establish with certainty whether these differences demonstrate a true shift in the age of pubertal onset because of difficulties of comparing these results with earlier studies. They suggest, however, that white girls appear to be developing 6 months to a year sooner than girls in the earlier studies. The age of menses appears to have remained stable in white girls over the past 45 years, whereas in African American girls it appears to have advanced by a little less than one-half year.
With respect to endocrine disruption, they state: "The possibility that the increasing use of certain plastics and insecticides that degrade into substances that have estrogen-related physiological effects on living things should be investigated in relation to the earlier onset of puberty.
Is Humanity Regressing Below the Level of Apes?
It is highly significant that Chimpansees, whose DNA is 98.5% indentical to ours, still begin to mature at the age of around 10 - 11 in the wild, and are sexually reproductive at the age of 12 to 13.
What is so extremely worrisome is that brain development is greatly reduced at the onset of puberty, as the body shifts to sexual development.
Worse, in an ongoing evolutionary process of further extending the human prepuberty cognitive growth and development phase, the onset of menarche had, within this century, begun to be delayed to as late as the age of 17*, allowing for further primary development of the human brain and cognitive capacity.
Compare this with the development of breasts and pubic hair at the age of 3 in 3% of Afrikan-American, and 1% of white girls in the US. And even more ominously, with 2 year-old baby girls growing breasts and pubic hair in Puerto Rico. (Source: "Teens Before Their Time", TIME Magazine, Oct. 30. 2000).
* "The decline in mean age at menarche from just below 17 years 100 years ago to around 13 years today in Western industrialized countries is usually considered a phenotypic response to improved living condidtions." (Marshall & Tanner, 1986).
This is total bunk. According to this (ahem) reasoning, the living conditions of Puerto Ricans should then be dramatically better than our's. Indeed, the reverse may well be true. It is well understood in the biological sciences that organisms under environmental stress devote all their resources to reproduction - as driven by the universal imperative to perpetuate their kind. This includes early reproductive maturity.
No, this phenomenon is man-made - by the ignorant and irresponsible use of chemicals in our food and environments. And since the Puerto Rican horror story also includes boys with well developed breasts, some as young as 4 and 5 years-old, it is quite clear that female growth hormones - most likely the estrogen fed to chickens (Puerto Rico is a major producer of chickens for the US fast food market), and/or the pseudo-estrogens in many common plastics, are involved. |
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[ TIME excerpt continued ] Chemical pollution in the food chain is being investigated now - specifically, DDE, a breakdown product of the pesticide DDT, and PCBs, once used as flame retardants in electrical equipment. Both chemicals mimic hormones that play a key role in the development of the reproductive system. Both chemicals are ubiquitous in the environment, and they persist in the body for years after exposure, says Dr. Walter Rogan, an epidemiologist at the National Institute of Environmental Health Sciences. For that reason, he chose PCBs and DDE for one of the very few large, long-term studies of chemical exposure and puberty in humans. Rogan and his colleagues began with some 600 pregnant women, measuring concentrations of the chemicals in their bodies. When their babies were born, the researchers then measured levels in the mothers' breast milk. Finally, the team monitored the children as they grew and entered puberty.The most prominent effect was that boys exposed to DDE and girls exposed to PCBs were heavier than their unexposed peers at age 14. The study also noted an intriguing fact: girls with high prenatal PCB exposure tended to hit the first stages of puberty a bit earlier than others.
Other chemicals being investigated are compounds used to make plastics. One is bisphenol A, or BPA. Like DDE and PCBs, it is a chemical cousin of estrogen and has been shown to affect the reproductive systems of lab mice. Another category of plastics ingredients, phthalates, may play a role in an epidemic of very early puberty in Puerto Rico, with girls as young as 2 growing breasts and pubic hair [ my emphasis ]. A study published last month suggests that a possible culprit could be phthalates, which are used, among other things, to make plastics flexible. (Note: the TIME article implies that the Puerto Rico epidemic was only in the 1980s. In fact it continues to this day.)
Doctors say early development has become too widespread to be treated as a medical aberration. In the past, girls who developed breasts before age 8 were often given hormone therapy to slow things down. But in a report being prepared for the Pediatric Endocrine Society, Kaplowitz and co-author Dr. Sharon Oberfield of Columbia University argue that most girls between 6 and 8 who develop breasts or pubic hair should be reclassified as normal and left untreated. "Three-, four- and five-year-old girls should still be managed aggressively," he says.
[Source: excerpted from: "Teens Before Their Time"; TIME Magazine, Oct. 30. 2000]
Here, and in stark contrast, is an item from the British Medical Journal
Menarcheal Age Remains the Same - May 4 2001
Menarcheal age is an important indicator of puberty. On page 1095 Whincup et al report on a comparative study of age of menarche between girls born in 1982-6 and girls born in the 1950s and 60s. They used self reported questionnaires from 1166 girls in England and Wales for the former and historical data for the latter. They found that the median age of menarche in contemporary British teenagers is around 13 years and that there has been no appreciable recent decrease in menarcheal age. However, 1 in 8 girls reaches menarche while still at primary school, so appropriate health information and sanitary facilities should be provided for them.
So, now we have to ask why in the US, and not in Britain?
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