Breast cancer will adversely affect one in eight American women within their lifetime, and it’s one of the most common cancers women are diagnosed with. Researchers have found that an individual’s likelihood of survival after diagnoses greatly depends on the stage of the cancer when identified. Despite global initiatives for more research, very little is known about the exact causes or cures for this serious disease. Many doctors are conflicted on how to approach treatment and the types of foods that are safe to eat during recovery. Recently, soy has become a major source of debate in the scientific community. While new research shows the potential of soy in preventing breast cancer, many doctors remain skeptical.
Soy Breast Cancer Research
The University of Southern California published studies in January of 2008 that concluded women who drank one cup of soy milk a day had decreased their risk of developing breast cancer by 30 percent. These results were further verified in the Shanghai Breast Cancer Survival Study. A group of 5,042 women who had previously been diagnosed with breast cancer participated in a four-year long study, and the results showed that women who regularly consumed soy had both a 32 percent reduction in recurrence risk and a 29 percent decrease in risk of death from breast cancer.
Following up on this discovery, the Journal of the American Medical Association found similar results in a paper published one year later. Soy products, the study revealed, may reduce the risk of breast cancer recurrence. Despite the forthcoming research about soy products, it is still not recommended as a strategy for breast cancer survivors to lower their recurrence risk.
Benefits of Soy
The Shanghai Breast Cancer Survival Study concluded that soy played a role in reducing breast cancer incidence because it negated the effect of dangerous, cancer-causing estrogen on breast tissue. Additionally, theorists have suggested soy can aid in preventing the growth of cancer cells by disturbing the process by which cancer tumors develop their own blood supply.
Another promising area of study is combining a soy-rich diet with the anti-breast cancer drug Tamoxifen. Tamoxifen works to defend against estrogen-dependent breast cancers in a similar way that soy blocks the breast tissue from being adversely affected by estrogen. One promising study showed that Tamoxifen and soy worked together to decrease the production of breast tumors and even reduce the size of existing ones.
The primary concern doctors have with recommending soy is the estrogen-like action that soy may have on remaining or newly formed cancer cells. Soy contains compounds called isoflavones that work in a similar way as estrogen. Some breast cancers, specifically hormone-receptor positive cancers, grow bigger with higher estrogen levels. Estrogen levels are strongly associated with breast cancer, and research has proven that estrogen promotes the growth of cancerous tumors in mice. Other studies have also shown that lifetime exposure to high estrogen levels increases an individual’s risk for developing the disease. In the past, women diagnosed with breast cancer have been advised to avoid soy because of its estrogen-like effects on certain cancers. While the newest research appears to contradict this theory, doctors remain hesitant to recommend soy until further research is conducted.
Susan G. Komen has given over $3.3 million towards furthering research on the effects of soy on breast cancer. The breast cancer foundation identified three key areas which require further scientific study. First, more in-depth studies need to be conducted on how high soy or soy-supplemented diets effects breast cancer risk. The Komen foundation also suggests testing whether soy has the potential to prevent the development of breast cancer or protect against genetic damage. Finally, experts agree that continued research is needed to study the potential of utilizing soy in conjunction with other breast cancer treatments to enhance the effectiveness of treatment.
While there have been several new research studies concerning the effects of soy on breast cancer, recovering cancer survivors and cancer treatments, so much more research needs to be done before experts will be certain about its effects. Carol Fabian, a professor at the University of Kansas Medical Center, explains, “after more than three decades of asking questions about the role of soy in breast cancer risk and recurrence, we still do not have the answers.” Until more research is published, soy will likely remain a controversial topic among cancer treatment professionals.