Pass the Veggies

Eating soy foods and cruciferous vegetables may reduce treatment side effects in breast cancer survivors.

Consuming soy foods such as tofu and edamame, and cruciferous vegetables such as cabbages, kale, bok choy, and Brussels sprouts, may be associated with a reduction in common side effects of breast cancer treatment in survivors, say a team of scientists led by Georgetown Lombardi Comprehensive Cancer Center.

In the study, published in Breast Cancer Research and Treatment, higher intakes of cruciferous vegetables and soy were associated with fewer reports of menopausal symptoms. More soy was also associated with less fatigue. The breast cancer survivors studied included 173 non-Hispanic white and 192 Chinese Americans.

Breast cancer survivors often experience side effects that persist long after completion of the treatment. To prevent breast cancer recurrence, many treatments inhibit the body’s production or use of estrogen, the hormone that can fuel breast cancer growth. Survivors may then experience hot flashes, night sweats, and vaginal dryness.

The lead author, Sarah Oppeneer Nomura, PhD, of Georgetown Lombardi, says that the study addresses a gap in research on the role of lifestyle factors in relation to treatment side effects. When quality of life is adversely impacted, she notes, it can lead to survivors stopping ongoing treatments, but diet may be a modifiable target to reduce symptoms.

When study participants were evaluated separately by race/ethnicity, associations were significant among white breast cancer survivors; however, while a trend was seen in the benefit for Chinese women, results were not statistically significant. Chinese women typically report fewer menopausal symptoms, and most already consume more cruciferous vegetables and soy. Whether the reduction in symptoms accounts for longtime use of these foods needs further investigation, says the study’s senior author, Judy Huei-yu Wang, PhD, of Georgetown Lombardi’s Cancer Prevention and Control Program.

Although cruciferous vegetables and especially soy foods may reduce breast cancer risk, soy food intake during breast cancer treatment remains a controversial topic. Soy foods contain a plant chemical genistein that resembles natural estrogens and activates the estrogen receptor. In laboratory experiments, genistein stimulates the growth of human breast cancer cells. However, studies in breast cancer patients consistently show that soy intake reduces the risk of recurrence. Until more research is conducted, breast cancer patients undergoing treatments should not start taking supplements containing genistein, says Leena Hilakivi-Clarke, co-author of the study and professor of oncology at Georgetown University.

“Women who have eaten soy foods as a part of a healthy diet should continue consuming them to potentially reduce some treatment-related side effects,” she adds.

This study focused on spinal fluid of CFS, GWI, and control subjects. Spinal taps before exercise showed miRNA levels were the same in all participants. In contrast, they were significantly different after exercise, with each study group showing distinct patterns of change. For example, CFS subjects who exercised had reduced levels of 12 different mRNAs, compared to those who did not exercise.

The two GWI subtypes showed other differences caused by exercise. One subgroup developed jumps in heart rate of over 30 beats when standing up that lasted for two to three days after exercise. Imaging showed they had smaller brainstems in regions that control heart rate, and did not activate their brains when doing a cognitive task. In contrast, the other subgroup did not have any heart rate or brainstem changes, but did recruit additional brain regions to complete a memory test. According to Baraniuk, finding two distinct pathophysiological brain patterns in patients reporting GWI “adds another layer of evidence to support neuropathology in the two different manifestations of Gulf War disease.”

The study lays the groundwork to understand each of these disorders in order to diagnose and treat them effectively, says Baraniuk.