Chemical or Acid Exposure May Cause Breast Cancer
Pesticides. Plastics. Cosmetics. Deodorants.
Cookware. Stain-resistant furniture. Computers.
What do all these seemingly unrelated items have in common?
At one time or another, all have been suspected of increasing the risk of breast cancer.
The important point to recognize is that most researchers agree that there are no solidly proven links between these -- or other similar environmental factors -- and the risk of breast cancer.
The troubling aspect of this, however, is that many believe it's just a matter of time before we connect the scientific dots and see a picture of increased risk.
"It's true that we have no direct links. But what we do have is a compilation of epidemiological studies, cell culture studies, and animal data that are all consistent and I believe are coming together to show us that some of what women are exposed to every day may be increasing their risk of breast cancer," says Janet Gray, PhD, professor and chairman of the department of psychology at Vassar College. Gray, together with experts from the University of Pittsburgh Cancer Institute, recently compiled a report on what we know thus far about the environmental links to breast cancer.
Gray says that while there may be no smoking gun that implicates any one area of concern, or even one chemical, she says the evidence is starting to mount indicating that steady, personal exposure to low levels of lots of different chemicals does matter.
"What's really new in this field," says Gray, is that "finally people are starting to look at interactions -- and the fact that exposure to low doses of lots of different chemicals may yield a result similar to a high-dose exposure to one chemical."
Our Chemical Exposure
And just how many chemicals are we exposed to on regular basis? According to Richard Wiles, senior vice president of the Environmental Working Group (EWG), more than you might imagine.
He reports that an ongoing EWG monitoring project which regularly tests blood, cord blood, urine, and breast milk from 72 adults has so far identified the presence of 455 chemicals that should not be in the body.
"If you had one or two you would say not a big deal. But you can't say that the whole 455 aren't doing something harmful to the body. That just doesn't seem plausible,"
Moreover, he reports that a recent EWG survey of some 2,300 Americans found that the average adult is exposed to 126 chemicals every day -- just in their personal care product use alone.
"One in every 13 women is exposed to a known or a probable human carcinogen (acid) every day, with one in every 24 women -- or 4.3 million total -- exposed to personal care ingredients that are known or probable reproductive and developmental toxins," says Wiles.
The Role of Genetics
While every woman has at least the potential to succumb to environmental influences, not every one will. What makes the difference? Our genetics -- the individual blueprint that governs how every cell in our body is supposed to act.
"Inside each cell is all our genetic material -- the total number of genes from both parents," says Smith.
The genes that are "expressed," she says, are those that we see -- for example, blue eyes or brown hair.
But what we see is only a small portion of our genetic makeup. Most of what is in our cells is "unexpressed" -- including our risk for certain diseases.
And while there are some clear-cut genetic links to breast cancer that a woman can inherit, this group makes up a relatively small segment of the breast cancer population.
What is likely to affect many more of us, says Smith, is a genetic predisposition -- a gene that is lying dormant in our body that, when awakened by some circumstance, increases the risk for breast cancer.
"Once the gene is aroused, it begins to express itself -- and that expression can cause the kind of cellular changes that eventually lead to cancer," says Smith.
Many believe that it is environmental exposures -- including chemicals -- that can awaken at least some of those dormant genes and put a woman on the cellular path to breast cancer.
While we can't change our genetics, to some extent, we can control our internal environment.
And while you may be thinking this means avoiding carcinogens -- chemicals known to cause cancer -- of far greater concern is exposure to what are called "endocrine disrupters."
These are chemicals and byproducts that, when inhaled, ingested, or absorbed through the skin, can either mimic the effects of estrogen in the body or cause estrogen to act in a way that isn't normal.
Since it is estrogen that can spark the growth of many tumors, Gray says anything that interferes with estrogen metabolism has the potential to cause harm.
"These chemicals cause a 'triple whammy' -- they increase levels of estrogen, alter cell metabolism, and influence the pathways that increase the risk of cancer," says Gray.
Antiperspirants and Breast Cancer
Based on a recent study in the Journal of Applied Toxicology, cancer researcher Philippa Darbre, PhD, of the University of Reading in England, says the evidence is mounting that the aluminum-based active ingredient in antiperspirants can mimic estrogen in the body.
At the same time, in a report released in 2004, officials with the National Cancer Institute wrote that there was "no conclusive research" linking the use of underarm antiperspirants or deodorants to breast cancer.
And the American Cancer Society (ACS) says that most research on environmental links to breast cancer remains unproven and that research linking deodorant use to breast cancer remains weak.
ACS spokeswoman Elizabeth Ward, PhD, previously said that there is not much evidence that any environmental exposure has a big impact on breast cancer risk. She points out that studies examining pesticides known to mimic estrogen have failed to show a link between exposure and breast cancer.
"This is a topic that is still under study, and it is important to study it further," she says. "But no strong evidence has emerged of a relationship [between breast cancer risk] and exposure to environmental contaminants."
Smith offers this advice: "You have to accept in life that there is a great deal we don't know -- and just stay as close as possible to a natural state of living. Cut down where and when you can and minimize risks when and where you can in all areas of your life."
Additionally, the Environmental Working Group offers an online database of some 14,000 personal care products rated by their level of chemical contaminants. (http://www.erbc.vassar.edu
Published Nov. 6, 2006.
SOURCES: Janet Gray, PhD, professor, Vassar College, Poughkeepsie, N.Y. Richard Wiles, vice president, Environmental Working Group, Washington, D.C. Julia Smith, MD, director, breast cancer screening and prevention, and director, Lynne Cohen breast cancer preventive care program, NYU Cancer Institute, and Bellevue Medical Center in New York City. National Cancer Institute web site: "Deodorants and Breast Cancer." American Cancer Society web site:
"Environmental Carcinogens." WebMD Medical News:
"Antiperspirant: Link to Breast Cancer?" Darbre, P.D.
Journal of Applied Toxicology, 2004; vol 24. Journal of the National Cancer Institute, Oct. 16, 2002.
Andersson, P.L. British Journal of Cancer, 1999; vol 58:
pp 50-57; Blout, B.C. Environmental Perspectives, 2000; vol 105: pp 970-982. Journal of Steroid Biochemistry and Molecular Biology, 2002, vol 80: pp 49-60. Darbre, P.D.
Journal of Applied Toxicology, 2004; vol 24: pp 5-13http://www.dreddyclinic.com/findinformation/cc/breastcancer.htm