Parents often think their children grow up too quickly, but few are
prepared for the problem that Dr. Michael Dedekian and his colleagues
at the University of Massachusetts Medical School reported recently.
At the annual Pediatric Academic Society meeting in May in San
Francisco, they presented a report that described how a preschool-age
girl, and then her kindergarten-age brother, mysteriously began growing
pubic hair. These cases were not isolated; in 2004, pediatric
endocrinologists from San Diego reported a similar cluster of five
children.
It turns out that there have been clusters of cases in which
children have prematurely developed signs of puberty, outbreaks similar
to epidemics of influenza
or environmental poisonings. In 1979, the medical journal The Lancet
described an outbreak of breast enlargement among hundreds of Italian
schoolchildren, probably caused by estrogen contamination of beef and poultry. Similar epidemics in Puerto Rico and Haiti were tracked by the Centers for Disease Control and Prevention in the 1980’s.
Increasingly — though the science is still far from definitive and
the precise number of such cases is highly speculative — some
physicians worry that children are at higher risk of early puberty as a
result of the increasing prevalence of certain drugs, cosmetics and
environmental contaminants, called “endocrine disruptors,” that can
cause breast growth, pubic hair development and other symptoms of
puberty.
Most commonly, outbreaks of puberty in children are traced to
accidental drug exposures from products that are used incorrectly.
Dr. Dedekian’s first patient was evaluated for possible genetic endocrine problems and a rare brain tumor before the cause of her puberty was discovered. It turned out that her testosterone level was almost 100 times normal, in the range of an adult man. The same problem affected her brother.
The doctors realized that the girl’s father was using a concentrated
testosterone skin cream bought from an Internet compounding pharmacy
for cosmetic and sexual performance purposes. From normal skin contact
with their father, the children absorbed the testosterone, which caused
pubic hair growth and genital enlargement. The boy, in particular, also
developed some aggressive behavior problems.
Sex hormones
are potent because they are easily absorbed through the skin and resist
degradation better than many other hormones. Unlike protein-based
hormones like insulin, sex hormones like testosterone and estrogen are
technically steroids, meaning they are derived from cholesterol.
Primarily made by the liver, cholesterol begins with tiny pieces of
sugar that are joined, twisted and oxidized in a dizzying series to
make an end product that resembles the interlinked rings of the Olympic
emblem. Dr. Joseph L. Goldstein, Nobel Laureate and a biochemist in
Texas, once called it “the most highly decorated small molecule in
biology,” because 13 Nobel Prizes have been awarded for its study.
Through further processing, primarily in the gonads and adrenal
glands, cholesterol is converted into sex hormones like estrogen and
testosterone. Kenneth Lee Jones, the former chief of pediatrics at the University of California, San Diego, noted pediatric cases similar to those described by Dr. Dedekian in a 2004 report in the journal Pediatrics.
At that time, unregulated “prohormones” like Andro, famously used by Mark McGwire,
the former St. Louis Cardinals power hitter, and banned by federal law
in 2005, were available as topical sprays used to enhance libido. Dr.
Jones said the sprays used by adults in some households permeated the
children’s bedsheets, and the early puberty stopped only when the
adults stopped using the sprays and also discarded old sheets.
Testosterone-containing products are not the only trigger of disordered puberty in children.
In a 1998 paper in the journal Clinical Pediatrics, Dr. Chandra
Tiwary, the former chief of pediatric endocrinology at Brook Army
Medical Center in Texas, reported an outbreak of early breast
development in four young African-American girls who used shampoos that
contained estrogen and placental extract. The early puberty reversed
once the shampoo was stopped.
In the tradition of previous physicians who deliberately exposed
themselves to possible pathogens, Dr. Tiwary tried the shampoos on
himself. He carefully measured his own levels of various male and
female sex hormones to establish his baseline, used the shampoos for a
few days, then repeated the tests.
While Dr. Tiwary is quick to admit that his unpublished findings
must be interpreted with great caution, some of his sex hormone levels
changed by almost 40 percent after he used the shampoos. In some cases,
substances other than sex steroids may also disrupt normal sexual
development. In Boston at the annual Endocrine Society meeting in June,
Clifford Bloch of the University of Colorado
School of Medicine presented several cases of young men who had
developed marked breast enlargement from using shampoos containing
lavender and tea tree oils, which are widely used essential oil
additives that present no problem for adults. (Unlike Dr. Dedekian’s
cases, these cases were not a result of passive transfer from parents.
The boys themselves used the shampoos.)
Dr. Bloch collaborated with scientists at the National Institute of
Environmental Health Sciences in North Carolina to test the oils on
human breast cells grown in test tubes. Lavender and tea tree oil had
the same effect on the cells as estrogen.
Dr. Bloch speculates that the findings, which he is submitting for
publication in a peer-reviewed journal, may explain the boys’ breast
growth. He noted, however, that cells in a test tube are a far cry from
humans, so the relationship of the essential oil to breast growth
remains hypothetical.
While pediatric endocrinologists have implicated pharmaceutical or
personal care products for causing pubertal problems in children, some
environmental scientists also claim that some widespread industrial and
pharmaceutical pollutants harm the normal sexual development of fish
and animals. By extension, they may also contribute to earlier or
disrupted puberty in children, these scientists contend. Robert
Kavlock, a senior reproductive toxicologist at the Environmental Protection Agency, said these concerns “caused a shift in worry from cancer to noncancer” effects of environmental pollution over the past decade.
In 1994, scientists found that estrogen-like chemicals from plastics
manufacturing plants that had contaminated sewers in England caused
genetically male fish to develop into females. In the early 1980’s,
major spills of the DDT-like pesticide dicofol in Florida led to the
“feminization” of the reproductive tracts of male alligators.
Ralph Cooper, the chief of endocrinology at the reproductive
toxicology division of the Environmental Protection Agency, says
various sources of endocrine disruptors, like manufacturing chemicals,
may be leaching into the environment. While their relation to pubertal
problems in children remains highly speculative, he believes further
study is needed.
Past epidemiological evidence, however, does worry Dr. Cooper,
because some chemical exposures have been associated with early
puberty. In 1973, thousands of Michigan residents ate food contaminated
by a flame retardant, PBB, which was later correlated with earlier
menstruation in girls. In Puerto Rico, which has some of the world’s
highest rates of early puberty, the condition was linked to higher
levels of a plasticizer called phthalate in affected children.
Governmental efforts to create a systematic method to assess
possible endocrine disruptors from environmental sources have stalled.
In 1996, Congress directed the E.P.A. to develop a comprehensive
screening program for possible endocrine disruptors within three years.
Dr. Cooper says no such program has begun operation, a failure he
attributed largely to stonewalling by chemical industry representatives
who serve on an advisory committee for the program. Now the proposed
rollout is December 2007, but Dr. Cooper said, “They may be dreaming.”
Critics cite the program’s high potential costs and lack of reliable
laboratory tests.
Protecting children from endocrine disrupters in cosmetics and prescription drugs may also be difficult in the near future.
In 1989, the Food and Drug Administration
proposed allowing up to 10,000 units of estrogen per ounce of cosmetic,
the approximate oral daily dose of hormone replacement therapy for
postmenopausal women. Dr. Tiwary said that in the early 1990’s he filed
an adverse drug report with the agency about hormone-containing
shampoos but that to his knowledge, it never came to anything.
Reached by e-mail, a spokeswoman for the F.D.A. said that the agency
was “aware of some reports describing premature sexual devolepment”
with shampoos but that it had concluded that “there is no reason for
consumers to be concerned.”
At this time, “placental materials are neither prohibited by cosmetic regulations nor restricted” by the F.D.A., she wrote.
Dr. Dedekian said that while prohormones like Andro are no longer
commercially available, lax regulation of so-called compounding
pharmacies allows the manufacture and sale of concentrated testosterone
creams, like the one affecting his patient, without government
oversight.
Topical lotions and creams containing testosterone may become more
common. In 2000, Solvay Pharmaceuticals secured F.D.A. approval for
Androgel, a lotion to treat a syndrome the company calls low T,
referring to low testosterone. According to the company’s Web site, the
condition affects 13 million men over 45. From 2000 to 2004, the number
of testosterone prescriptions doubled to over 2.4 million a year.
Solvay Pharmaceuticals referred questions on Androgel’s possible
risks to Natan Bar-Chama, an associate professor of urology at Mount
Sinai School of Medicine.
Dr. Bar-Chama acknowledged the theoretical risks of transfer of the
hormone through skin contact with children, but he said he had never
seen a case among the hundreds of men he has treated. He added,
however, that it was prudent to take precautions when using the
product, including hand-washing after handling the gel and wearing
clothing to avoid skin-to-skin contact with others.
In 2003, an Institute of Medicine
report stated, “There has been increasing concern about the increase in
the number of men using testosterone and the lack of scientific data on
the benefits and risks of this therapy.”
Dr. Dan Blazer, a psychiatrist at Duke who was chairman of the
committee, said, “In no way did we find a condition that we defined as
low T.”
The major clinical trial of Androgel’s effectiveness for low T,
published in The Journal of Clinical Endocrinology and Metabolism in
2000, included neither a placebo group (patients who received an
inactive dummy lotion) nor a control group (patients who did not have
low T) for comparison.
Dr. Ronald Swerdloff, the chief of endocrinology at Harbor-U.C.L.A.
Medical Center in Torrance, Calif., and a consultant for Solvay, who
ran the study, said the trial was limited in scope since it examined “a
new route of administration for an already established drug.”
Darshak M. Sanghavi is a pediatric cardiologist at the University of Massachusetts Medical School.
Correction: Oct. 27, 2006
An article in Science Times on Oct. 17 about cases of puberty in very
young children omitted the author’s affiliation. The author, Dr.
Darshak M. Sanghavi, is a pediatric cardiologist at the University of
Massachusetts Medical School, as is an expert he quoted, Dr. Michael
Dedekian.
Correction: Nov. 6, 2006
An article in Science Times on Oct. 17 about
cases of puberty in very young children misstated the given name of an
Environmental Protection Agency official who commented on efforts to
determine whether manufacturing chemicals may play a role. He is Ralph
L. Cooper, not Robert. The article also misstated the surname of an
E.P.A. official who spoke about possible noncancerous effects of
industrial and pharmaceutical pollution. He is Robert J. Kavlock, not
Havelock.
<a href="http://www.nytimes.com/2006/10/17/science/17puberty.html?ei=5088&en=ed072921988bcaee&ex=1318737600&adxnnl=1&partner=rssnyt&emc=rss&adxnnlx=1162938223-jfHzOHYzZ5SNGKg3Q4CW0g">Preschool Puberty and a Search for the Causes</a>
Darshak M. Sangavi
The New York Times
October 17, 2006
<a href="http://www.holology.com/hormone.html">Sex Hormone Pollution </a></p>