Many of us stick to healthier-than-average routines: We’re vigilant about sunscreen use, aim to eat an abundance of fruits and vegetables every day, include fish in our diets, and walk up a sweat a few times each week. But within our good habits, we may expose ourselves to more harm than we imagine, even increasing our risk of developing breast cancer.
It’s a disease you may not worry about, especially if no one in your family has ever had it. But surprisingly, only 1 in 10 breast cancer cases has a genetic connection. “Genes don’t tell the full story,” says Devra Davis, Ph.D., director of the Center for Environmental Oncology at the University of Pittsburgh and author of “The Secret History of the War on Cancer.” “Genes sometimes give us the gun, but the environment pulls the trigger. Breast cancer isn’t born; it’s made.”
Alcohol consumption has been proven to help pull that trigger, and obesity and exposure to ionizing radiation (used in X-rays and CT scans) have also been linked. But environmental toxins from a wide range of sources are also increasingly in physicians’ sights. “My personal thought is that environmental factors may one day be definitively linked to an increased risk of breast cancer,” says Gena Carter, M.D., an American Cancer Society spokeswoman and a diagnostic radiologist who specializes in breast imaging.
Indeed, research in the field of environmental oncology already suggests that chemicals in our daily environment may significantly contribute to our risk. Although most of the evidence is based on animal studies, many medical professionals recognize its validity. “Much of the breast cancer research in mice translates very well into humans,” says Carter. She speculates that the connection between environmental toxins and breast cancer seems weaker than some other links only because the research is ongoing.
Scientists have long known that a woman’s exposure to estrogen — from the length of time between her first period to her first successful pregnancy and from sources like hormone replacement therapy and some forms of birth control — increases her breast cancer risk. In the past 15 years, they’ve discovered that compounds found in air pollution, pesticides, cleaning and beauty products, and plastics can act like estrogen when they enter our bodies, which may further increase our risk.
Taking into account the ubiquitous chemicals that contribute to cancer in other ways, plus recent discoveries about how these compounds accumulate in our bodies, it’s easy to feel paranoid — or resigned. But Davis sees plenty of reason for hope, and action. “We have some control over our environment, unlike most other factors,” she says. “We can reduce our risk by changing our behavior.” Read on to find out what steps you can take now.
Chemical Connection
If our bodies flushed out all the toxins we ingest from nonorganic food, inhale while cleaning or exercising outdoors in a city, and absorb from our beauty products, we wouldn’t have much cause to worry.
In fact, scientists originally believed that in small doses, toxins proved harmless. But recent research reveals that many chemicals bioaccumulate, or build up in our bodies, over time. A small dose of a certain chemical 10 years ago becomes a big dose if we’re continually exposed to it.
Consider, too, that exposure to one chemical can come from myriad sources. The same toxins created when grilling fish or meat (known as polycyclic aromatic hydrocarbons, or PAHs, which can increase DNA mutations), for instance, also lurk in air pollution. So the PAHs from last year’s Labor Day cookout, now lodged in your cells, may be sitting alongside the ones you breathed during your commute this morning. “It’s that collective exposure over time that may set the stage for cancer,” Carter says.
Individual toxins aren’t just lone wolves roaming our bodies, either. Evidence now shows that different toxins team up — and the sum is stronger than their parts. The parabens from an eye cream could join with the ethyl oxide from your moisturizer and the dioxin you ingested from an apple sprayed with pesticides.
Cleaning with a toxin-containing product once in a while may not give you breast cancer. “But when combined with all the other environmental factors, and when you’re doing it for 50 years, it can be harmful,” says Janet Gray, Ph.D., Vassar College professor and editor of State of the Evidence 2008: The Connection Between Breast Cancer and the Environment.
One recent study looked at the combined effects of 11 different environmental contaminants — all at levels so low they didn’t individually pose harm — and demonstrated that together these chemicals increased one another’s effects.
Breast cancer seems especially tightly bound to environmental chemicals because of the number of them that mimic estrogen. In fact, many are believed to rev up cells’ estrogen receptors, causing them to replicate too fast. When that happens, “there’s a greater chance the cell will make mistakes,” explains Davis. “It’s like asking someone to complete a three-hour project in five minutes.”
Replication errors can cause abnormal cell growth to blossom into tumors. Meanwhile, other chemicals act by unlocking the door for their toxic friends to waltz through. A recent laboratory study on rats, for instance, showed that applying octyl methoxycinnamate, a common ingredient in sunscreens, can enhance the penetration of an endocrine-disrupting herbicide — one of the most common in the nation — used for weed control.
What’s more, many carcinogens are lipophilic, meaning they hang out in fat cells. “Fat cells are our natural hazardous-waste sites,” explains Davis. “They’re like Pac-Mans, gobbling up all the fat-loving organochlorines [chlorine compounds] from chemicals.” She points to studies on polar bears and beluga whales: Despite their relatively pristine environments and a diet high in fish, they have the highest levels of pollutants in their bodies of all animals — simply because they have more fat. The fact that breast tissue is made up largely of fat cells may make it especially susceptible to environmental toxins.
Play It Safe
The chemicals may have us surrounded, but we’re not doomed. We can limit our exposure to some of the most dangerous toxins — and take steps to help our bodies flush out the rest.
Green your cleaners. “Look under your sink,” says Davis, and scan the labels on all your household cleaning products for ingredients that contain alkyphenols, which mimic estrogen in the body. Also avoid names like methoxyphenol and nonylphenol. If you’re uncertain, make your own products or opt for natural brands.
Make over your medicine cabinet. Scour your makeup bag and medicine cabinet for products with questionable ingredients: Phthalates (often a component of fragrance, but not listed on ingredients), parabens, and ethylene oxide are estrogen mimickers. As Davis points out, the skin is our largest organ, and anything we put on it can seep through (consider patch-delivered drugs such as nicotine). With that in mind, says Davis, put things on your body that you can eat,” such as oils, plant extracts, and vitamins.
Watch what you eat. Limiting your consumption of grilled meats and fish will curb your exposure to PAHs and aromatic amines, which have caused mammary tumors in rodents and can affect cell division in ways that might enhance the development of breast tumors. Keep in mind that the fattier the meat is, the more likely it contains stored-up chemicals. When you do buy meat and dairy, choose organic. The same goes for fruits and vegetables: Eating organic helps you avoid pesticides, which cuts the chance of ingesting dioxins and atrazine, a known endocrine disruptor.
Make progress on plastics. Now take stock of the plastic in your life. To avoid estrogenic effects, avoid hard plastics that contain bisphenol A. Also avoid softer, more flexible plastics made from polyvinyl chloride (PVC), which can contribute to cancer by damaging DNA. Swap in stainless steel or glass containers instead, and look for natural beauty brands that use glass jars as well as yoga mats and shower curtains made from natural materials or labeled “PVC-free.”
Breathe easier. As for avoiding air pollution, Gray suggests closing your car’s air-circulation vents (especially on highways or near construction zones, where diesel-fueled vehicles are more common) to decrease your exposure to PAHs, as well as to two carcinogenic fossil-fuel byproducts, 1,3-butadiene and benzene. These byproducts also lurk in cigarette smoke, so avoid secondhand smoke whenever possible (and if you smoke, quit). When walking, biking, or jogging, avoid busy streets to reduce your chemical intake. If you live near a highway and enjoy keeping your windows open, invest in an air purifier.
Detox. Building in regular detox strategies can help ensure that the cancer-causing chemicals you do take in don’t get too comfortable. Fitness should head up any detoxification plan, says Davis, since “exercise lowers the amount of unbound estrogen in women.” This indirectly cuts our exposure to the hormone, which is the key to cutting breast cancer risk. Eating antioxidant-rich fruits and vegetables such as broccoli and berries, as well as omega-3 fatty acids from fish like wild salmon or ground flaxseed, can help the body flush out toxins. If you’re overweight, reducing your body mass index (BMI) to 30 or below can help your cells release some of the chemicals lingering in them. (To calculate your BMI, visit nhlbisupport.com/bmi/.)
Finally, consider cleaning the slate with traditional detox methods such as saunas and panchakarma, an ancient Ayurvedic purification technique. They have little science behind them but lots of anecdotal evidence, says Davis.
Saunas induce sweating, one of the ways our bodies release toxins. Panchakarma, offered at some Ayurvedic health centers, incorporates warm oil massage and steam therapies to loosen toxins from organs and muscles, as well as herbal enemas and cleansing of the nasal passages and sinuses. Visit ayurveda.com/panchakarma or chopra.com/panchakarma for more information.
Being vigilant about avoiding chemicals takes effort, says Gray, but the long-term benefits outweigh the initial challenges. Make changes that fit into your lifestyle, she suggests, and they’ll soon become healthy habits.
