Research links breast cancer, beef hormones
By Dennis Bueckert / The Canadian Press
Ottawa - Consumption of hormone-treated beef may be causing girls to
reach puberty earlier than they used to and making them more susceptible
to breast cancer, say researchers attending a world conference on breast
It is "very likely" that hormone residues in North American beef is a
factor in the early onset of puberty among girls in recent decades, said
Carlos Sonnenschein of the Tufts University School of Medicine at
"There is no other reason to explain it," Sonnenschein said in an
Pediatricians say the onset of menstruation has steadily decreased in
recent decades. The average age for a first period is now 12½, up from
age 14 in 1900.
Early onset of puberty with its raging hormones translates into higher
risk of breast cancer, said
"The length and amount of exposure to estrogens (a class of hormones) is
one of the most significant risk factors in breast carcinogenesis.
"Unless you are exposed to estrogens you don't get breast cancer. The
longer the exposure is, the higher the incidence. Therefore if you
decrease the age of menarche (first menstruation) . . . you
are at higher risk."
Hormones are used by cattle farmers in Canada and the United States to
increase the weight of cattle prior to slaughter. They are currently the
focus of a major trade dispute between North American and the European
Annie Sasco, of the International Agency for Research on Cancer at
Lyons, France, said more study is needed but it makes sense that
hormone-treated beef could affect the onset of puberty.
"Any exposure to a high level of hormones is associated with earlier
onset of puberty. It needs to be
studied more but it makes sense."
She said the risk of breast cancer associated with hormone residues in
meat is not proven, and is probably small.
"We all have estrogens and we need estrogens," she told the mainly
female audience. "They are needed for life, for being what we are. We
cannot say, 'Ban estrogens.'
"We all have to try, through our diet and physical exercise, to keep our
levels down. But there is a
need to keep things in perspective . . . without getting into a complete
Even if the risk is small, she said it would be prudent to stop the use
of hormones in the cattle industry there's no offsetting health benefit
The European Union has banned the use of hormones for fear they pose a
health risk, and has banned imports of hormone-treated Canadian and U.S.
The two North American countries have taken the dispute to the World
Trade Organization and have won the right to retaliate by placing
tariffs on European goods. Canada announced retaliatory tariffs on a
range of goods this week.
The federal government maintains the hormones are safe, despite strong
misgivings on the part of its own scientists at the Health Protection
Four scientists with concerns have been placed under orders not to
discuss the issue in public.
The incidence of breast cancer has been rising steadily, most quickly in
rich countries. In 1997, around the world, close to 400,000 women died
of the disease.
The number of new cases reported annually approached 900,000 in 1997,
up from 572,000 in 1980.
To Unsubscribe: Email email@example.com with the command
"unsubscribe sanet-mg". If you receive the digest format, use the command
To Subscribe to Digest: Email firstname.lastname@example.org with the command
All messages to sanet-mg are archived at: