The study, which was published in the journal Breast Cancer Research and Treatment, found that increasing some women’s intake of soy foods and cruciferous vegetables could reduce the menopausal symptoms seen in those undergoing treatment. Breast cancer survivors can suffer from cancer treatment side effects for years after the treatment has concluded.
Many of the treatments that are used to keep breast cancer from recurring halt the body’s use or production of estrogen, as this hormone spurs breast cancer growth. This leads many breast cancer patients to experience menopausal symptoms like night sweats and hot flashes, affecting their quality of life and sometimes causing them to abandon ongoing treatments.
The researchers studied 173 non-Hispanic, white breast cancer survivors, and 192 Chinese Americans, to reach their conclusions. It is important to note that the association between the foods studied and the symptom relief was significant among the white women studied but not among the Chinese women, who tend to report fewer of these menopausal symptoms in the first place. One explanation for why the Chinese breast cancer survivors did not see such a big impact is because they tend to eat a lot of soy foods and cruciferous vegetables, anyway – with those in this study eating twice as much of these foods as the white breast cancer survivors.
However, there is a huge caveat here. Preclinical studies carried out in animals show that the biologically active compounds in cruciferous vegetables and soy can actually cause breast cancer cells to grow; the opposite effect is seen, however, in animals that consume these foods well before being diagnosed with cancer, and who continue to eat them during treatments and afterward.
Oncology professor, Dr. Leena Hilakivi-Clarke, of Georgetown Lombardi, one of the study’s co-authors, warned that breast cancer patients should avoid suddenly starting to consume soy if they have not done so in the past. It is also worth keeping in mind that most soy foods sold in the U.S. – such as tofu, edamame and soy milk – are made with genetically modified soybeans, so if this study’s results are inspiring you to change your diet, it might be better to focus on cruciferous vegetables instead. "Choosing organic soy products is the easiest way to avoid genetically modified soy," explained Mike Adams, the Health Ranger, author of Food Forensics and founder of CWC Labs. "You can also look for Non-GMO Project certification on product labels."
Some of the best cruciferous vegetables are Brussels sprouts, broccoli, kale, bok choy, collard greens and cabbages. Be sure to choose organic varieties to avoid pesticide exposure.
The researchers believe that the isoflavones found in the soy products and the glucosinolates found in the cruciferous vegetables could be responsible for the benefits. Isoflavones bind to estrogen receptors to create a weak estrogenic effect, while glucosinolates could help alleviate symptoms by impacting the levels of metabolizing enzymes controlling inflammation and estrogen levels.
Yoga has also been found to be beneficial for breast cancer sufferers on the physical level as well as emotionally. In a 2011 study, for example, yoga was found to enhance the quality of life for women undergoing radiation therapy for breast cancer. The women who practiced yoga reported improvements in physical functioning and overall health, along with lower levels of fatigue and the stress hormone cortisol. Higher levels of cortisol can make breast cancer outcomes worse, so keeping it under control is an essential part of healing.