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Xenoestrogens and Breast Cancer:
Nowhere to RunBy Luita D. Spangler This article was originally
published in Winter 1996 in WomenWise magazine. WomenWise is the quarterly health-oriented
publication of the Concord Feminist Health Center in Concord, New Hampshire. This
article is copyrighted and is re-printed here with permission from the publisher.
For more information, contact Concord Feminist Health Center at 603-436-7588. Luita
D. Spangler impatiently awaits the revolution while teaching literature and working
as a healthworker. Thanks to
the efforts of persistent, outraged and energetic women's health advocates, many
people are now aware of the fact that the incidence of breast cancer has reached
epidemic proportions in the U.S. and is rising steadily throughout the globe.
The possibility that a woman in North America will contract the disease has risen
from one chance in twenty in 1950 to the current rate of one in eight. In the
U.S., the rate of breast cancer among white women from 1950 to 1989 increased
by 53% or by over 1% annually. Today, breast cancer is the most prevalent type
of cancer in women, and is the leading cause of death among women between the
ages of 40-55. Every year 182,000 American women will be diagnosed with breast
cancer; 46,000 women die of the disease annually. And despite occasional optimistic
noises from organizations like the American Cancer Society and the National Cancer
Institute, 5-year survival rates for the three main national cancer killers -
lung, breast and colo-rectal - have remained unchanged for decades.
Three
major classes of risk factors for breast cancer have been recognized by such conventional
cancer organizations as the American Cancer Society. The first factor is a familial
history of breast cancer, particularly breast cancers that occur among pre-menopausal
women; this factor has fueled the recently publicized search for a "breast
cancer gene." Not to diminish the importance of any research advance in the
battle against breast cancer, but researchers estimate that this factor may account
for only 5% of the total incidence of breast cancer, in spite of all the recent
media ballyhoo about this gene. Dietary fat has been counted as a risk factor,
although this link is controversial, the research evidence for this connection
has been tenuous and inconsistent.
The third accepted factor involves
a woman's lifetime exposure to estrogen, since estrogen has been proved to promote
breast tumors. Important risk elements in a woman's life involve her overall exposure
to estrogen include early menarche (onset of menstruation), late menopause, and
childlessness or late childbearing. A woman's exposure to "exogenous hormones"
(hormones produced outside of the body) may also be an important component; this
would include prolonged use of oral contraceptives, the use of the injectable
contraceptive Depo-Provera and Norplant contraceptive silicone rods, and long-term
postmenopausal estrogen replacement therapy.
These three factors
combined, however, can only account for about 25% of breast cancers, and can't
explain breast cancer's dramatic increase in frequency within the last fifty years.
There is actually a strong rationale for the current breast cancer epidemic,
but efforts to research and publicize the evidence for this probable determinant
have encountered heavy political resistance. Organochlorines
Are Toxic In 1990, Elihu Richter and Jerry Westin, two environmental
specialists from Hebrew University's Hadassah School of Medicine, discovered a
surprising glitch in otherwise universally depressing breast cancer statistics.
They found that in the decade between 1976 and 1986, Israel was unique among 28
counties surveyed in that it actually registered a significant drop in breast
cancer mortality. This was in spite of increasing risk factors in the Israeli
population, such as per capita fat intake and increasing patterns of delayed pregnancy,
and previous Israeli breast cancer rates that paralleled the international epidemic.
As Westin noted, "All and all, we expected a rise in breast cancer mortality
of approximately 20% overall, and what we found was that there was an 8% drop,
and in the youngest age group, the drop was 34%, as opposed to an expected 20%
rise. So if we put those two together, we are talking about a difference of about
50%, which is enormous."
Westin and Richter eventually connected
this drop in breast cancer mortality to a 1978 Israeli ban on the use of three
organochlorine pesticides (a ban, by the way, that was opposed by the Israeli
cancer establishment). Prior to 1978, alpha-benzene hexachloride (BHC), gamma
benzene hexachloride (lindane) and DDT were used heavily in Israeli cowsheds.
As a result, the three pesticides heavily contaminated milk and milk products,
at rates between 100 and 1,000 times greater than in the U.S., national public
outcry resulted in legislation prohibiting these three pesticides.
Critics
quickly challenged this suggested connection between breast cancer mortality and
pesticide exposure, claiming that since most environmentally-induced cancers take
at least twenty years to develop, the drop in mortality happened too quickly to
associate with the prohibition of the three pesticides. In reply, Westin and Richter
explained that organochlorine pesticides are "complete" carcinogens,
which both initiate and promote tumor growth, and whose presence (or absence)
can change cancer statistics quite rapidly. Actually, animal
experiments conducted back in the 1960's proved that organochlorine pesticides
caused breast cancer in rats. Like so many other animal studies, however,
the results and their suggested human parallel were totally ignored when they
proved inconvenient to the international chemical industrial machine. Other research
conducted nearly thirty years ago demonstrated that organochlorine pesticides
concentrate in animal and human fat tissue. As early as 1981, one research study
concluded that organochlorine pesticides "might be considered possible contributors
to the high incidence of breast cancer among women."
Such pesticides
as DDT, dioxin and atrazine are called "organochlorines" because they
are organic compounds containing chlorine bonded to carbon. Organochlorines are
also produced in the manufacture of herbicides, detergents, including those present
in the production of spermicidal foam or lubricants, petrochemicals such as polychlorinated
biphenyls (PCBs), PVC plastics and paper. Organochlorines have only recently been
synthesized; their massive introduction into the international chemical industry
began after World War II. DDT, for example, was introduced in 1943 by the U.S.
as a pesticide for the military's anti-malarial campaigns, and widespread civilian
use began two years later after the end of the war.
As environmental
pollutants, however, organochlorines are now everywhere. According to Greenpeace thirteen
tons of chlorine are produced in North America every year. One percent is used
to chlorinate drinking water, while the rest is used in the production of plastics,
to bleach paper products, and for many other industrial and agricultural uses.
Dumped into landfills, chlorine based compounds leak into soil and water, and
eventually collect in the tissues of living organisms. Incinerators burn chlorine-containing
trash, releasing organochlorines into the atmosphere. In animals (yes, humans
are animals) organochlorines are stored in fat tissue and, since these substances
are inefficiently metabolized, they stay in the body forever and accumulate. Because
of this, the amount of organochlorine in the bodies of animals becomes more and
more concentrated as they move up the food chain. Of course, human beings sit
right at the top of the food chain, ingesting and amassing organochlorines like
crazy. The first report of DDT in animal milk was published in 1945; the first
reports of DDT in human fat and human breast milk appeared three years later.
[Go
to end of article for what you can do
to reduce your
organochlorine exposure.] Recent scientific research has
clearly demonstrated an association between organochlorines and breast cancer.
An analysis of chemical plant workers in Hamburg, Germany discovered a two-fold
increase in breast cancer among the women workers who had been exposed to dioxin
contamination. Significantly higher levels of breast cancer have been found in
separate studies of women living near organochlorine chemical plants in Minnesota
and Long Island. Other studies have revealed elevated breast cancer mortality
among professional chemists, among hairdressers and users of hair dye.
Analyses of the breast fat of women with breast cancer found that DDT, its derivative
DDE, polychlorinated biphenyls (PCBs) and other organochlorine pollutants actually
concentrate in the cancer tissue itself, in contrast with surrounding non-cancerous
tissue. In one study, the biopsied breast fat of women with breast cancer contained
forty percent more chlorinated pesticides than tissue from women whose biopsies
proved negative. Mary Wolff, an associate professor of environmental and occupational
medicine at the Mount Sinai School of Medicine in New York, examined archived
blood specimens from women in New York City. Wolff, who claims to have been "a
skeptic all along about the environmental connections to breast cancer, but I
keep being proven wrong," discovered that the blood from women who later
developed breast cancer registered much higher levels of DDE. The results from
this study, published in the April 21, 1993 Journal of the National Cancer Institute,
lead Wolff to suggest that women exposed to such pesticide derivatives may face
up to four times greater risk for developing breast cancer.
Wolff concludes
her article with the suggestion "that environmental chemical contamination
with organochlorine residues may be an important etiologic factor in breast cancer.
Given the wide-spread dissemination of organochlorine insecticides in the environment
and the food chain, the implications are far-reaching for public health intervention
worldwide." Such a blunt statement prompted an immediate reaction from the
ranks of the conventional cancer establishment. Stephen Sternberg, for example,
a doctor working with the Memorial Sloan-Kettering Cancer Center in New York,
in direct response to Wolff's research, complained in a following issue of the
same publication that "we appear to be in the middle of an uproar regarding
breast cancer." Worrying about "misdirected funding," he went on
to fuss that "the findings by Wolff et al require a more conservative conclusion
before costly intervention studies are undertaken in an attempt to implicate organochlorine
compounds in causation. …I suggest that more caution be taken in ascribing
possible causation of breast cancer to DDT and other organochlorines. The media
and the public have a tendency to misinterpret or indulge in hyperbole in evaluating
such reports."
One may wonder why one of Mary Wolff's anti-cancer
colleagues would react in such a grumpy fashion to an apparent advance in the
fight against breast cancer. Actually if organochlorines are seriously implicated
in the present epidemic of breast cancer, the existing cancer research establishment
may be testy indeed. It is an unfortunate fact that much of the cancer research
currently going on is actually funded by the very same chemical companies that
are filling the environment with organochlorine pollution.
For example
the United Kingdom-based Zeneca Group is a primary corporate sponsor and funding
source for the U.S. National Breast Cancer Awareness Month. Zeneca also coincidentally
markets Nolvadex, the trade name for tamoxifen citrate, a synthetic anti-estrogen
used to treat breast cancer, to the tune of $470 million a year. Despite the fact
that tamoxifen has been implicated as a possible cause of uterine cancer, liver
damage, and other health problems, the drug is now being tested among a population
of 16,000 perfectly healthy women as a breast cancer preventative (the consent
form for this drug trial was changed after the National Cancer Institute was accused
of withholding information about the risk of endometrial cancer and tamoxifen).
Zeneca, recently spun off from its parent corporation, Imperial Chemical Industries,
also manufactures and sells $300 million a year's worth of acetochlor, a carcinogenic
herbicide, and was named in a government lawsuit for dumping DDT and PCBs into
Los Angeles and Long Beach harbors. In 1988, a third of the leadership board of
the Memorial Sloan-Kettering Cancer Center, Stephen Sternberg's patron institution,
had direct ties to the oil, chemical, automobile and cigarette industries. One
of their fund-raising appeals, proudly outlining their latest research directions,
makes no mention of environmental causes of breast cancer, but brags that "MSK
scientists are seeking to understand the role genes play in breast cancer, to
identify genetic markers that correlate with increased risk, and to find ways
of intervening, possibly through gene therapy, to prevent or cure the cancer."
If the current breast cancer epidemic could be traced simply to the international
use of organochlorine pesticides, the task of promoting global pesticide elimination
would be daunting enough. Unfortunately, the association between these pesticides
and breast cancer merely reflects the tip of a rather grotesque iceberg. Organochlorines
Mimic Estrogen Organochlorines are not only often overtly toxic,
they also possess estrogenic activity; in other words, they mimic estrogen. Basically
natural hormones function by attaching to cell receptors that are designed specifically
for that hormone; once connected, they trigger various chemical changes in the
body. Natural bodily estrogen, or estradiol, tends to be disassembled relatively
quickly by the body and is then eliminated from the bloodstream. Chemicals that
function like estrogen (called "xenoestrogens," literally, "foreign
estrogens") wreck havoc in a number of ways. By taking up a receptor site,
they can prevent a natural hormone from binding and block in its normal function.
They can move into the nucleus of a receptor cell and disrupt the cell's growth
and division. Xenoestrogens are known to exaggerate the carcinogenic effects of
radiation, and may increase the breast cancer risk among women who were subjected
to prenatal exposure to these substances.
In addition, estradiol in the
body seems to be metabolized in two distinct ways. One end of an estrogen molecule
has two carbon atoms; the other end has sixteen. Estrogen, which is metabolized
through the two-carbon end seems to be innocuous, but a sixteen-carbon metabolite
stimulates uncontrolled cell proliferation and allows groups of cells to grow
without anchoring to a surface - two important factors needed for the development
of cancer. Sixteen-carbon metabolites are also toxic to cellular DNA. Synthetic
xenoestrogens apparently block the 2-carbon pathway and promote 16-carbon metabolism.
(In contrast, natural plant xenoestrogens, like those occurring in broccoli, cabbage,
and cauliflower, favor the carbon metabolite.) Finally, they tend to stay in the
body and remain active for a much longer time than natural estrogen, giving them
the opportunity to do the body enormous harm.
Unfortunately, organochlorines
are merely one type of a current flood of xenoestrogens recently introduced into
our environment. The synthetic hormone Diethylstilbestrol (DES), given
to women in the 50's and 60's to (ineffectively) prevent miscarriage, with cancerous
results for both the women and their children, is still widely used in the meat
industry as a feed supplement to put weight on animals scheduled for slaughter;
the hormone is, of course, passed on to people in the meat. The dairy
industry is currently awash in rBGH, a artificial hormone developed to stimulate
dairy cows into producing more milk for an already glutted market, with dire results
for the cows and as yet unknown effects on human consumers. Xenoestrogenic material
leaches out of polycarbonate plastics, often used in food and cosmetic packaging
- even tin cans thinly lined with polycarbonate plastic leak estrogen into their
contents. Light pollution, the global trend toward filling the environment
with artificial illumination, also seems to be compounding the problem; melatonin,
a natural hormone secreted at night by the pineal gland, has anti-estrogenic properties
and may inhibit the development of cancer, but is suppressed by the presence of
artificial light. The production of melatonin is also reduced by the presence
of even very weak electromagnetic fields, such as those associated with radio
waves and household microwave ovens. Not
Just Women Affected, Males too Of course, this deluge of xenoestrogens
doesn't just affect women, although the epidemic of breast cancer may be its most
dramatic manifestation at present. Global wildlife has been bearing the primary
brunt of environmental pollution for decades, and there is mounting documentation
of hormonal disruption among certain species. Indeed, the well-known link between
DDT and fatally thin eggshells among such birds of prey as the bald eagle is a
perfect example of such xenoestrogen-related destruction.
Finally, there
is increasing evidence that the ubiquitous presence of synthetic estrogen in the
environment is beginning to take its toll on the health of men, as well. International
incidences of testicular cancer, undescended testes and hypospadias (in which
the urethral openings on the penis is on the underside rather than the tip) are
sharply on the rise, while the average male sperm count is dropping equally as
rapidly; researchers have discovered that semen from the average man today has
half the amount of sperm in it, and of poorer quality, than that of fifty years
ago.
Seen in the light (literally) of global industrial pollution, the
epidemic of breast cancer ceases to be a mystery and becomes a measure of the
times. Equally measuring the times has been the industrial reaction to this accumulating
chemical indictment. Instead of working to eliminate and prevent xenoestrogenic
pollution, the chemical industry and its medical cohorts have responded by pouring
more drugs into the environment to counter actthe effects of previously introduced
synthetic substances; by concentrating their research on high profile but less
significant factors, like the elusive breast cancer gene; or by concentrating
on expensive and technologically seductive cancer therapies, like gene therapy.
Declining male fertility has been counteracted with invasive and dangerous drugs
and surgical procedures aimed entirely at women's reproductive systems. With
all this in mind, it is natural to ask, what can a woman do to minimize her chances
of coming down with breast cancer? At the moment, individual strategies are limited,
at best. Breast feeding before the age of thirty has been demonstrated to be a
protective act; unfortunately, the theory behind this is that a woman decontaminates
her breasts of organochlorines and other environmental carcinogens by passing
the toxins out through her breast milk - into her infant. Since organochlorines
accumulate in animal fat, eating a low-fat diet seems a logical preventative step,
although the most recent studies seem to indicate that greatly reducing fat from
one's diet after reaching adulthood has no protective value. Trying to avoid industrial
pollution is also a good idea, albeit a bit difficult for those of us who choose
to participate actively in life on the planet.
Individual solutions are
obviously no answer to the international epidemic of breast cancer, but collective
organizing and action may be. And this is just what is beginning to take place.
In 1991, women from a collection of grass-roots organizations converged on Washington
DC to form the National Breast Cancer Coalition. At present, this coalition has
grown to comprise nearly 300 member organizations and thousands of individuals
across the country. In October 1993, Greenpeace released its report Chlorine, Human Health
and the Environment: The Breast Cancer Warning, a compilation of studies
clearly linking chlorine-based chemicals to the epidemic of breast cancer. At
the same time, the American Public Health Association (APHA) unanimously passed
a resolution urging U.S. industry to stop using chlorine.
Since then,
a number of women's health organizations, feminist groups, environmental groups
and general health organizations have joined forces to demand fundamental change
in the battle against breast cancer and other environmentally-induced diseases.
As Joan D'Argo, a worker with Greenpeace, explains, "Breast cancer is a harbinger
of other environmental diseases. We need to meet face-to-face with the chemical
industry in diverse gatherings; if we don't, the corporate world will just threaten
to take their business elsewhere." As an example of this sort of organizing,
here in New Hampshire the New Hampshire Breast Cancer Coalition has joined forces
with the Seacoast Anti-Pollution League, the Women's Cancer Awareness Project
(Seacoast Region) and Greenpeace to form the Toxic Links Collaborative.
One main obstacle this burgeoning movement faces is the nation's archaic method
of testing possible environmental toxins; at the moment, organochlorines are tested
individually for their carcinogenic potential. This method entirely overlooks
the fact that their effects on the body are interactive and cumulative. Therefore
it is impossible to isolate out the villainous effects of one xenoestrogenic substance
from the thousands of other mixing with it in our environment. Another obstacle
is the global distribution of these environmental toxins: when one substance is
banned in one nation, it may be heavily marketed and used in other, less restrictive
countries. This is especially true in developing nations; for example, in Costa
Rica, annual pesticide use can reach levels equivalent to eight pounds per person,
double the average level of use in industrialized countries.
Nevertheless,
the international cry of alarm over organochlorine pollution and its cost in human
and environmental health is growing louder. And the chlorine industry is not ignoring
this growing sound. The Chemical Manufacturers Association (a lobby representing
more than 170 chemical companies), the Chlorine Institute, and many pulp, paper
and incineration organizations have combined their financial resources to launch
a massive public relations counter-attack. You will be seeing their advertisements
more and more frequently now, in magazines, newspapers, even on television, promoting
chlorine as a hygenic substance as natural as mother's milk. It's not. But
it's in it. SOURCES (for article above) Following
is a partial list, for a complete list call the author at 603-436-7588. - Anditti,
Rita and Tatiana Schreiber, "Breast Cancer: The Environmental Connection."
Sojourner, December 1992, 13-15.
- Davis, Devra Lee and H. Leon Bradlow.
"Can Environmental Estrogens Cause Breast Cancer?" Scientific American,
October 1995, 166-172.
- Epstein, Samuel S. "Environmental and Occupational
Pollutants are Avoidable Causes of Breast Cancer." International Journal
of Health Services 24:145-150 (1994).
- Greene, Gayle and Vicki Ratner.
"A Toxic Link to Breast Cancer?" The Nation, 20 June 1994, 866-869.
- Raloff,
Janet. "EcoCancers." Science News, 3 July 1993, 10-13. Thornton, Joe.
Chlorine, Human Health and the Environment: The Breast Cancer Warning. Washington:
Greenpeace, 1993.
- Wolff,
Mary S., aolo G. Toniolo et al. "Blood Levels of Organochlorine Residues
and Risk of Breast Cancer." Journal of the National Cancer Institute 85:
648-652 (1993).
WHAT
YOU CAN DO -
Reduce or eliminate use of
plastic containers for food storage. -
Ask for office
paper products whitened without chlorine. -
Purchase
non-bleached coffee filters, paper, napkins, toilet tissue, tampons, etc. The
EPA has determined that using bleached coffee filters alone can result in a lifetime
exposure to dioxin that exceeds acceptable risks. -
Use
tampons and sanitary napkins made of organic cotton without chlorine. (The FDA
detected dioxins and dozens of other sugstances in conventional tampons. Look
for ones that contain no chlorine, fragrance, wax, surfactants, rayon, etc.) -
Do not use chlorine bleach for household cleaning or laundry.
Hydrogen peroxide is a safe alternative; it breaks down to water and oxygen. -
Drink filtered or bottled water, not "city water" that
contains chlorine. -
Do not use pesticides or herbicides. -
Regard long-time use of synthetic or animal derived hormone treatments
(oral contraceptives and hormone replacement therapy) with healthy skepticism,
investigate natural and plant-derived alternatives for HRT. -
Don't
purchase plastic products (their production releases chlorinated toxins into the
environment). -
Use only natural underarm deodorants;
avoid anti-perspirants. -
Eat a low-fat diet, but be
cautious of synthetic fat substitutes (avoid animal foods that contain hormones
such as milk, chicken, beef, pork). Avoid fried, char-broiled, or barbecued as
forms of cooking. -
To counter free radicals, eat foods
high in anti-oxidants (vitamins A, C, E, selenium, beta carotene) - green leafy
vegetables, kale, carrots, yams, sweet potatoes, citrus, nuts, broccoli, cauliflower).
Avoid acohol and caffeine/coffee. -
Eat organically
grown food.
FOR MORE INFO, CONTACT
Health
Care Without Harm - read about efforts to eliminate harmful plastics from
the health care industry. My
House is Your House - read about the second most used plastic, polyvinyl chloride
(PVC), and how you can join the movement to phase out the use of this serious
environmental and health hazard.
Breast
Cancer Action
55 New Montgomery St #624
San Francisco, CA 94105
415-243-9301 "Reach
for Unbleached"
WA Citizens for Resource Conservation
4649 Sunnyside
Ave N.
Seattle, WA 98105
206-343-5171 WA
Toxics Coalition
4516 University Way NE
Seattle, WA 98105
206-632-1545 Greenpeace
USA
1436 U St NW
Washington DC 20009
202-462-1177
http://www.greenpeace.org
Center
For Health, Environment and Justice
P.O. Box 6806
Falls Church, VA
22040-6806
Phone 703-237-2249
Dr.
Andrew Weil on "Eating to Prevent Breast Cancer" Dr.
Andrew Weil on Anti-Oxidants The
Breast Cancer Fund - links between breast cancer and environmental toxins
In
1964, the World Health Organization
concluded that 80% of cancers were due to human-produced carcinogens. In 1979,
the National Institutes of Health
identified environmental factors as the major cause of most cancers. Yet, only
a tiny fraction of the National
Cancer Institute budget goes to research on prevention.
Feminist Women's Health Center |
