In your Facebook feed, in conversations with friends, in a magazine article—the talk about natural remedies for preventing and treating breast cancer seems to pop up everywhere. But which natural products are actually being tested in the lab and in clinical trials, and what’s the evidence for their effectiveness?
Saraswati Sukumar, Ph.D., Johns Hopkins oncology professor and founding director of the Kimmel Cancer Center’s Breast Cancer Program, has been studying natural compounds and their effects on cancer, and she says it’s too early to tell yet whether certain natural remedies can reduce the number of women who develop breast cancer, or whether any of them can help women with breast cancer live longer. But there are a few of these remedies that are being tested at Johns Hopkins and elsewhere, with promising results.
Curcumin: Curcumin is the active ingredient in turmeric, the yellow spice in curry powder, that has been used in the Indian Ayurvedic medicine tradition for centuries, according to Sukumar. “We have studied it extensively for many years in cells and in animals, and eventually it is ready to make the big jump into human clinical trials,” she says.
One of curcumin’s “most important effects is that it reduces inflammatory reactions,” says Sukumar. For breast cancer patients, this means that curcumin pills taken during and after radiation treatment could help heal burns and deep wounds, as studies conducted at the University of Rochester have shown. Sukumar and her colleagues are also testing curcumin in mice, to see if small doses of the compound can prevent cancers from growing, or possibly shrink the size of breast tumors that are already present. So far, these studies haven’t turned up any harmful side effects of curcumin; in fact in several mouse models of breast cancer, curcumin has helped reduce the number of tumors, and aided chemotherapy and hormone therapy to shrink the tumors. Sukumar cautions that it does act as a blood thinner, so it wouldn’t be a safe choice for patients who are already taking blood-thinning medications like heparin or Coumadin.
Honokiol: Another natural compound being studied by Johns Hopkins researchers is honokiol, a compound extracted from the seed cones and bark of the magnolia tree. Dipali Sharma, MS, Ph.D., an associate professor of oncology, is testing honokiol in mice to see whether it can slow the growth of breast cancers fueled by leptin, a hormone closely connected with obesity and cancer in humans.
Broccoli sprouts: Johns Hopkins cancer prevention expert Kala Visvanathan, M.D., is conducting clinical trials of a broccoli sprout compound called sulforaphane in women who have been treated for breast cancer and in women and men at high risk for the cancer. In animal studies, sulforaphane has been shown to “turn on” proteins that protect cells against breast cancer. Others scientists are studying similar compounds called isothiocyanates, found in things like horseradish and cruciferous vegetables like broccoli, cabbage and Brussels sprouts, to see if they can protect against breast cancer as well.
Red wine and soy: Natural compounds found in red wine and soybeans have been studied by breast cancer researchers for decades, with some positive results, Sukumar says. In particular, the red wine chemical resveratrol has been shown to suppress tumor growth in studies of breast cancer cells and cancers in animals. In soybeans and soy products, compounds called isoflavones also have been successful in animals to prevent breast cancer and slow tumor growth. Isoflavones are plant estrogens, so researchers are positive about its cancer preventive properties, but cautious about its use in women with cancer, since the breast cancers use estrogen to grow, Sukumar says.
One more thing to remember about natural remedies is that scientists are often testing the pure form of these compounds, rather than how they appear in our foods. However, adding a handful of broccoli sprouts to your salad regularly or mixing a teaspoonful of turmeric into your meal can help to reduce your risks of cancer, Sukumar says.