Bob King's personal annotations on this page
Graphictruth bookmarked
on 2007-08-07
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Doctors are increasingly worried about the number of girls - and boys - being referred to specialists because of this phenomenon of 'precocious' puberty.
The normal age at which puberty starts in both boys and girls has dropped by about two years since the 19th century, to 14 for boys and 12 for girls. This is largely due to improved nutrition - onset of puberty is believed to be triggered by physical size. Another theory is that the epidemic of obesity is to blame.
But modern social conditions may also be a contributory factor. Research suggests that children from broken homes experience earlier puberty. The stress of family breakdown apparently alters the balance of growth hormones and other chemicals in the body, speeding up a child's physical development.
Absent fathers may be another cause. American researchers have found that biological fathers send out chemical signals that inhibit their daughters' sexual maturity. Girls whose fathers had left home started their periods earlier.
Early puberty has even been linked to watching too much television. A few years ago, Italian scientists found that children who watched three hours a day produced less of the sleep hormone melatonin - low levels of the hormone play an important role in the timing of puberty.
But perhaps more worrying is the theory that it's exposure to environmental chemicals which is causing the drop in the age of puberty. These chemicals mimic the effect of hormones, disrupting the normal timing of sexual maturing.
This link has been bookmarked by 1 people . It was first bookmarked on 07 Aug 2007, by Bob King.
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Doctors are increasingly worried about the number of girls - and boys - being referred to specialists because of this phenomenon of 'precocious' puberty.
The normal age at which puberty starts in both boys and girls has dropped by about two years since the 19th century, to 14 for boys and 12 for girls. This is largely due to improved nutrition - onset of puberty is believed to be triggered by physical size. Another theory is that the epidemic of obesity is to blame.
But modern social conditions may also be a contributory factor. Research suggests that children from broken homes experience earlier puberty. The stress of family breakdown apparently alters the balance of growth hormones and other chemicals in the body, speeding up a child's physical development.
Absent fathers may be another cause. American researchers have found that biological fathers send out chemical signals that inhibit their daughters' sexual maturity. Girls whose fathers had left home started their periods earlier.
Early puberty has even been linked to watching too much television. A few years ago, Italian scientists found that children who watched three hours a day produced less of the sleep hormone melatonin - low levels of the hormone play an important role in the timing of puberty.
But perhaps more worrying is the theory that it's exposure to environmental chemicals which is causing the drop in the age of puberty. These chemicals mimic the effect of hormones, disrupting the normal timing of sexual maturing.
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