I’m not surprised people are asking questions about this, because the whole issue of soy is really confusing right now. To bring you some answers, I’ve consulted with doctors and researched countless studies. Here’s what I’ve gleaned so far.

Soy contains an abundance of “phytoestrogens,” or natural plant compounds that can behave as weak estrogens in both animals and humans. Their role in the plant is to protect it from stress and serve as part of the defense system, so naturally many scientists (and nutritionists) believed that soy could help protect human bodies as well.

Here’s a taste of the confusion. Early studies suggested that soy may help lower LDL cholesterol levels, thereby reducing the risk of heart disease. Later studies, however, have found no such affect on cholesterol. Some studies suggested soy could help you lose weight, but others showed it didn’t help much. Some studies found soy could help control insulin levels, but others disputed those results as well. A few years ago soy was all the rage to help reduce menopausal symptoms, but more recent studies have question whether it does any good. Related studies thought that soy could help reduce the amount of bone loss, but later studies seem to have debunked that theory, too.

When we look at cancer, we find no more clarity. A recent study from October 2010 reported that women past menopause who have had cancer could reduce their risk of recurrence with a higher intake of soy. Researchers warned, however, that the study was small and included only women with breast cancer who were receiving care in China. Other studies seem to confirm this protective effect against not only breast cancer, but colon and prostate cancer. Some animal studies, however, have found that phytoestrogens may negatively affect breast cells, actually increasing the risk of tumors. Lab studies have also shown that various mixtures of phytoestrogens stimulated breast cancer cell growth in humans.

Overall, it looks like what science has found so far is that phytoestrogens like those found in soy can be both preventive and promoting when it comes to cancer, and that it depends on the dose, the timing of the exposure, and the type of phytoestrogen—and, whether or not the cancer is estrogen dependent. Clear as mud, right?

Until science can tell us more, what do we do? We have to consider several things. First of all, our exposure to environmental estrogens has increased a lot over the past 20 years. It’s not like we need to consume more! Second, soy is a good source of fiber, B vitamins, omega-3 fatty acids, and protein—but human studies are showing conflicting results as to the effects of phytoestrogens on human health.

“What I’ve been telling my patients right now,” says Dr. Richard Lee, medical director of the Integrative Medicine Program at MD Anderson Cancer Center, “is that soy as part of a healthy balanced diet is safe. But I would avoid trying to eat a totally soy-based diet or taking a soy supplement.”

Reviewing all this, here’s my take: If you’re concerned about estrogen-driven breast cancer (which can include breast, ovarian, uterine, cervix, endometrial, and prostate cancer), stay away from soy and other phytoestrogens, particularly in supplements. Enjoying a few soybeans now and then will probably benefit your health, but remember that soy is in a lot of products that we don’t think about, like soy milk, soy sauce, miso, tempeh, and tofu. It’s also often added to foods like breads, cereals, and meats, and used as a meat substitute in vegetarian products (read labels). Particularly if you have breast cancer (or other estrogen-driven cancers) in your family, you may want to limit your exposure to soy until we find out more.

You may want to be cautious, as well, with any personal care products that contain soy. Most contain such small amounts as to be of little concern, but remember that the skin can absorb what’s put on it, especially if we’re talking about lotions and creams and things you don’t rinse off. Soy provides antioxidant and anti-inflammatory effects and can help fortify skin, but again, my advice would be that if you’re avoiding soy on the whole, stay away from products that list soy in the first 10 ingredients or so.

Finally, if you’re trying to get pregnant or if you are pregnant, you may want to cut back on your soy intake. Studies have found that soy phytoestrogens may reduce the odds of a successful pregnancy. The National Institutes of Health are also currently conducting studies to evaluate the long-term effect of soy infant formula on the development of children.

What do you think about the whole soy confusion? Please share your thoughts.

Photo courtesy Daniel Hurst Photography via Flickr.com.

Like parabens, phthalates, and pesticides, aluminum can act like estrogen in the body, affecting estrogen receptors and increasing breast cancer risk. Laboratory research shows that aluminum salts, common in most deodorants, can directly bind to estrogen receptors, and can affect estrogen-regulated gene expression in breast cancer cells.

“Lifetime exposure to estrogen is the risk factor which is tied most strongly to breast cancer,” said lead researcher Philippa Darbre, Ph.D., of the University of Reading in England. “If the aluminum salts in antiperspirants enter the body and mimic estrogen it stands to reason that constant exposure over many years may pose a risk.”

Currently, there are no definitive studies linking the use of antiperspirants to an increased risk of cancer. The American Cancer Society still considers commercial deodorants to be safe. Live Green Mom, however, has this to say about those who might have us turn a blind eye to recent studies: “Doctors and researchers always have to say ‘may pose a risk’ or ‘could possibly….’ They cannot speak in absolutes until all research is done and considered conclusive. Until everyone agrees. And not everyone is going to agree, naturally. It isn’t in ‘everyone’s’ best financial interest to agree.”

Read a little more about aluminum and it just doesn’t sound good. According to researcher Dr. Chris G. Mcgrath, M.D., 90% of breast cancer is linked to the environment or a particular lifestyle. “The closest environment to the breast is the underarm and the closest Western lifestyle is the daily application of antiperspirants, deodorants, or more commonly in combination. This daily routine is more often then not, preceded by underarm shaving….Westernized women are applying chemical compounds in antiperspirants/deodorants on the skin daily over decades. These compounds have not been studied long term with respect to skin absorption and possible toxicity. The breasts and underarms are directly linked by the skin and lymphatic system. Interesting when the incidence of breast cancer since the 1940s is plotted against the same time period of antiperspirant/deodorant sales, an eerie parallel is seen.”

Mcgrath goes on to say that in one of his studies, he found that women who more frequently used antiperspirants and shaved their underarms were diagnosed with breast cancer at a significantly earlier age than those who did these habits less frequently or not at all. Other studies have found that aluminum is absorbed through the skin, and has been found in breast tissue of women who have had mastectomies.

Why do manufacturers use aluminum anyway? Well, it’s very effective in preventing sweating. Basically, it plugs up the sweat glands. However, you do have alternatives. Dr. Mcgrath recommends Terra Natural’s deodorants, whose motto is, “Why take a chance if you don’t have to?” Their ingredients are all plant or food based. You can also try the crystal deodorant stones we mentioned in our last post. Finally, Tom’s of Maine makes several non-aluminum deodorants, as does Burt’s Bees.

Have you changed your underarm routine? Share your story!

Photo courtesy HurtRich via Flickr.com.

So, based on what we know so far, it makes sense for most women to try to reduce their exposure to estrogen. However, just how to do that seems to be getting more complicated. Most of us know that hormone-replacement therapy (HRT) after menopause has been discouraged by health organizations because of studies linking it with an increased risk of breast cancer. And the debate continues on birth control pills, as to whether or not today’s low-estrogen formulas do anything to raise risk. (Some studies have shown a slight increased risk, others have shown no change in risk, while multiple studies have shown birth control to decrease risk of ovarian and endometrial cancers.) However, we don’t expect to have to worry about estrogen exposure from food, plastic containers, or skin-care products. Unfortunately, that is the reality of today, and women wanting to reduce their risk will want to become more aware of what they’re putting in and around their bodies.

First, we have the estrogens found in food, or in plants used as foods. These are usually called “phytoestrogens,” and are found in soybeans and tofu (which is why these foods are often recommended for post-menopausal women who are low on natural estrogen), and in some whole grains, fruits, and vegetables. However, unlike synthetic forms of estrogen, these natural forms seem to help reduce the risk of breast cancer, mostly because they act like estrogen in the body, but are less potent, and so are thought to help women avoid estrogen-related disease.

Next, we have the environmental estrogens—synthetic chemicals that can act like human estrogen. Research has found that these estrogens can increase cell division and potentially contribute to breast cancer risk. These types of estrogens are found in pesticides, food preservatives like BHT and BHA, compounds used in plastics like bisphenol A and pthalates, food dye Red #3, and formaldehyde (used in making carpets, plywood, and some nail polishes). Science still isn’t sure of the impact of these estrogens, but theorizes that the more exposure one has, the bigger potential for increased risk of cancer.

Finally, we have estrogens showing up in our personal-care products. We’ve already posted about phthalates, parabens, and other hormone-like chemicals. Here’s something new: a recent report in the Journal of Clinical Oncology warns that rejuvenating skin creams often contain estrogen. In fact, 40 percent of those tested contained what researchers are calling significant amounts (up to 0.61%) of estriol or estrone, two potent forms of estrogen. According to skincarerx.org, estrogen is “used in some facial creams designed for dry and lined skin and permitted in creams by the FDA in low dosages.” Estrogen helps the skin retain water, and may improve skin tone on a limited basis—but at what risk? Dr. Lorne Brandes, writing for CTV MedNews Express, warns women who are undergoing treatment for breast cancer to be especially concerned about any product that could raise the level of blood estrogen through the skin. Healthy women, as well, need to be concerned about their overall exposure to estrogens.

How can you tell if your moisturizer contains estrogenic compounds? First, check out our list of ingredients to avoid, and stay away from products that contain parabens, pthalates, chemical sunscreens, and the like. Next—since estrogens aren’t always listed on the label (those in the previous study were not)—buy from reputable companies producing organic and natural products, like jeune d’age, Burt’s Bees, and Pristine Planet, among others. Check your favorite products against the Environmental Working Group’s Skin Deep Database for safety.

Have you found a favorite hormone-free skin-care product? Let us know.

Photo courtesy si-art via Flickr.com.