The Hazards of Estrogen

Plant and environmental estrogens may contribute to breast cancer
Illustration by Joseph Daniel Fiedler

When Joyce Gant discovered that the estrogen she was taking to chill her hot flashes was the same estrogen spoon-feeding her breast cancer, she immediately started hunting for a substitute. Eager to replace the prescription hormone therapy that she’d used for almost 10 years, she searched drugstores and turned up an over-the-counter pill that she thought might work.

She showed it to her doctor, and what happened next was an awakening.

“His comment was, ‘That’s based on soy, and soy is a plant-based estrogen’,” says Gant, who’s 63 and lives in Belleville.
Since any estrogen, no matter its source, may contribute to certain types of breast cancer, Gant promptly decided to take no chances. She returned the over-the-counter medication and changed her diet as well.

“To this day, I avoid anything with soy in it,” she says.

Gant now steers clear of soy sauce, tofu, and anything containing soybean oil: multivitamins, energy bars, and salad dressings, among them. And she is now vigilant about reading labels.

“You would be amazed at the number of products and processed foods that have some soy product in it,” she says.

For Gant and the 2.5 million other breast-cancer survivors in the United States who want to prevent a recurrence of their disease, and for those at high-risk due to family history or other factors, the evidence on soy and other soy-based products as cancer causers is hazy. Some studies suggest a link, but in countries where soy intake is high, such as Japan, the incidence of breast cancer is low.

However, until all the evidence is in on products such as soy milk and tofu, consuming products that use soy as a concentrate or extract is not a good idea, says Dr. Ruth Lerman of the Beaumont Breast Care Center. “Then we’re turning food into a pharmaceutical,” she says of such products and practices. “Since we don’t really even know the effects of soy as a food, to look to it as a drug is not good.”

And there are additional questions about using soy for women receiving chemotherapy treatments or who are taking breast-cancer or osteoporosis drugs. Those are best answered by her doctor, says Lerman, herself a breast-cancer survivor. Lerman is a senologist, an internal-medicine doctor who specializes in conditions and diseases of the breast.

Her advice? Exercise, keep a healthy body mass index (BMI) and avoid alcohol and hormone-replacement therapy. For questions on soy, supplements, and other products, she goes to the interactive website for Memorial Sloan-Kettering Cancer Center in New York ( for answers.

Women’s quest for beauty and soft skin may also play a role in increasing their risk for breast cancer. The effects of estrogen-like chemicals such as parabens, placenta extracts, and benzophenones in lipstick and other makeup, personal-care products, and even sunscreen are still emerging as a subject for research, says Dr. Suzanne M. Snedeker, a visiting fellow at Cornell University.

“The whole area of environmental estrogen is still a concern,” says Snedeker, who is researching 56 environmental estrogens in ultra-violet protectors, which include sunscreens. Because environmental estrogens are weaker than the body’s natural hormone, studies have focused on their collective effects. Also important are what time in life a woman is exposed to them and for how long, Snedeker says.
“Everything points to a relationship between breast cancer and long estrogen use,” she says.

Meanwhile, research on estrogen and its effect on breast cancer continues. The Women’s Health Initiative (WHI), a 15-year federal project to study disease in more than 150,000 post-menopausal women, concluded that hormone therapy with estrogen alone has an uncertain effect on breast cancer. But combination therapy with estrogen and progestin (a synthetic version of another female hormone, progesterone) resulted in increased risk. In fact, the risk was so high that researchers ended the study early.

The WHI, along with the Food and Drug Administration, recommends that “hormone therapy be used at the lowest doses for the shortest duration needed” for moderate to severe hot flashes and to prevent osteoporosis in women at high risk who can’t take other medications.
Other research demonstrates that if ever there was a reason for a woman to eat right and keep fit, breast cancer is it.

Study results are fairly clear that excess weight increases the risk of breast cancer, and there are many studies that saexercise has a protective effect against it, says cancer specialist Dr. Michael Simon of the Wayne State University Physician Group.

“Certainly, trying to maintain a normal body weight is good for you anyway,” says Simon, who’s also a professor of oncology and medicine at the Karmanos Cancer Institute. “And you don’t have to have a Miss America-type figure.”

Simon takes a moderate approach to risk. He suggests limiting hormone-replacement therapy to a few years, or taking vitamins or an anti-depressant for hot flashes. Because of alcohol’s protective effects against heart disease and its weak effect on risk for breast cancer, he suggests moderation. “Certainly having a glass of wine or two on the weekends is not going to be harmful,” he says.

Other experts add that women who have risk factors should be genetically tested if necessary and take time to educate themselves on what they put into their bodies and how it may play out with their high-risk status, experts say.

Some women are following that advice. For example, Denise Saccaro of Berkley wanted to learn about how food plays a role in estrogen-fed breast cancer like hers and sought the advice of a dietitian. That was the first step to becoming “90-percent” vegan, says the longtime Eaton Academy employee. Saccaro’s weekday grocery basket contains grains, legumes, vegetables, and fruits. “Then when the weekend comes, I can have a treat like a veggie hot dog,” she says. Even then, the 43-year-old Berkley wife eats no meat or fish and limits soy-based protein subs like the ones in veggie hot dogs to three times a week.

Processed foods with mysterious ingredients are definitely history for Saccaro. “The chemicals and the additives — all these things I can’t pronounce,” she says. “I’d rather eat an organic apple.”

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