Does soy prevent breast cancer or increase the risk?
The debate heats up this month as part of Breast Cancer
“It's a myth that soy prevents breast cancer,”
says Kaayla T. Daniel, PhD, author of The Whole Soy
Story: The Dark Side of America's
Favorite Health Food. “Numerous studies show
that soy can cause, contribute to or even accelerate the
growth of cancer.”
In spite of the most recent research showing the association
between soy products and breast
cancer women are still being urged to purposefully
increase their consumption of soy
milk and soy foods in the mistaken belief that soy
will prevent or even cure breast cancer.
Dr. Daniel explains, “The truth is that soy protein
contains dangerous levels of plant estrogens.
Although not identical to human estrogens, these have
been proven to increase breast cell proliferation, a widely
accepted marker of breast cancer
“The soy industry consistently plays down the evidence
that soy can promote breast cancer,” says Dr. Daniel.
“It is even using Breast Cancer Awareness Month
as an excuse to push its products on unsuspecting women.”
Companies using Breast Cancer Awareness Month as part
of their marketing efforts include Vitasoy, which has
launched a breast health education initiative that includes
giving away soy milk in bright pink containers –
called “Pinkies” - to women attending Breast
Cancer Awareness Month activities such as the upcoming
Komen Races for the Cure in Boston and Miami.
“The soy industry also heavily promotes the myth
that Asians have lower rates of breast cancer because
of soy consumption,” says Dr. Daniel. “In
fact, Asians eat soy in very small quantities, as a condiment
in the diet and not as a staple food. What's more, they
eat old-fashioned, whole soybean products such as miso,
tempeh, natto and tofu, not the new heavily processed
products marketed by the soy industry such as soy milk,
veggie burgers and 'energy bars.'”
Dr Daniel points to a Japanese study published this month
in the journal, Cancer Causes and Control, in
which researchers at Nagoya
that soy consumption offers no protection and has no effect
on breast cancer risk.
“The researchers were curious as to whether Asians
enjoy lower rates of breast cancer because of their soy
consumption,” she says. “Using data from the
Japan Collaborative Cohort (JACC) they examined whether
soy foods really have a protective effect. They found
that Asians on high soy diets
did not have a lower incidence of breast cancer. Clearly
it's time to credit other dietary and lifestyle factors
for their lower rates of breast cancer.”
Leading scientists and government agencies share Dr. Daniel's
concern. The Israeli Health Ministry has advised women
to “exercise caution” when it comes to soy
consumption because of increased breast cancer risk.
The French Food Agency will soon require warning labels
on soy milk and other soy foods because of the risks to
women who've been diagnosed with – or have a family
history of - breast cancer.
In the U.S.,
Center for Breast Cancer and Environmental Risk Factors
has examined the evidence on soy and phytoestrogen-containing
herbs such as black cohosh and warned women not to self
medicate with soy foods or soy supplements.
“The risks are well established. Soy is clearly
not the answer for breast cancer prevention,” concludes
Dr. Daniel. “The evidence is mounting that soy may
even be part of the problem.”