Natural hormones found in dairy products may elevate risk of a
number of hormone-dependent cancers such as testicular cancer, prostate cancer
and breast cancer in dairy consumers, Harvard University Gazette reported on December
7.
Ganmaa Davaasambuu, a physician from
Mongolia with a Ph.D. in environmental Health earned
from
Japan,
told her fellows about the dangers of cow's milk, cheese, and other dairy at
Radcliffe Institute for Advanced Study, according to the report.
Ganmaa is a working scientist at Harvard School
of Public Health.
Cancer has been linked to dietary hormones - particularly
estrogen, which has raised concern among scientists because natural estrogens are
up to 100,000 times more potent than the environmental pollutants such as the
estrogen-like compounds in pesticides, Ganmaa was cited as saying. Dairy
products account for 80 percent of estrogens consumed.
"The milk we drink today is quite unlike the milk our
ancestors were drinking" without apparent harm for 2,000 years, Ganmaa was
quoted as saying. "The milk we drink today may not be nature's perfect
food."
Ganmaa said the milk produced in the modern countries
differs from the one produced in
Mongolia where the milk producers
do not harvest milk from pregnant cows. An estrogen compound (esterone sulfate)
in milk collected from pregnant cows, particularly during the late stage of
pregnancy can be up to 33 times higher than milk from a non-pregnant cow.
Milk produced in
Japan,
according to the report, contains 10 times more progesterone than raw milk from
Mongolia.
Ganmaa was cited as saying that the prostate
cancer death rate in
Japan
has been linked to dairy consumption, zero per 100,000 five decades ago versus
7 per 100,000 today.
The rate is much higher in the
U.S. where 230,000 men are
diagnosed with prostate cancer each year and over a million men live with the disease,
according to the U.S. National Institute of Cancer.
Incidence of testicular cancer among men ages 20 to 39 in
Switzerland and
Denmark
where cheese is commonly consumed is highest in the world whereas the incidence
is lowest in
Algeria
and other countries where dairy is not so widely consumed, the report said.
Harvard studies have already found that the hormone levels
jumped in Mongolian children after they were fed commercial
U.S. milk for a month.
Ganmaa was cited by the Gazette as saying that butter, milk,
and cheese as well as meat and eggs are implicated in higher rates of
hormone-dependent cancers. Breast cancer has been linked particularly to
consumption of milk and cheese.
While the dangers of milk are not fully understood, what can
be done now is to reduce the hormone levels in milk and adopt a Mongolian milking
model, Ganmaa was cited as saying.
That
is, milk should be collected only from non-pregnant cows for the lowest hormone
level.
"The dairy industry in the
United States is not going to change
in any radical way," the Gazette quoted artist Shimon Attie, the Mildred
Londa Weisman Fellow at Radcliffe - and a former dairyman as saying.
The report did not say if there is any danger from the genetically-engineered
bovine growth hormone (rBGH) injected into dairy cows to promote milk
production.
U.S.
milk is banned in Europe and
Canada
because of the injected hormone, according to preventcancer.com, which claims
that rBGH raises risk of breast cancer.
Neither did the report mention the level of hormones in the
U.S. milk although it did say that
U.S.
skim milk has a low hormone level as the Mongolian milk does.
Hormones are fat-soluble and skim milk is not
expected to contain too much of any hormone.