Cruciferous Veggies Boost Survival in Breast Cancer Patients

Posted by on Apr 11, 2012
in the category Oncology

Source Medscape News Today

by Roxanne Nelson

April 10, 2012 (Chicago, Illinois) — The consumption of cruciferous vegetables might have a positive impact on survival in breast cancer patients, according to the results of a new study.

The Shanghai Breast Cancer Survival Study, a large population-based prospective cohort study of Chinese breast cancer survivors (4886 women), showed that eating cruciferous vegetables after a diagnosis of breast cancer was associated with improved survival in a population of Chinese women. The results were presented here at the American Association for Cancer Research 103rd Annual Meeting.

The researchers, led by Sarah J. Nechuta, MPH, PhD, a postdoctoral research fellow at Vanderbilt University in Nashville, Tennessee, found that after adjustment for confounders such as demographics, clinical characteristics, and lifestyle factors, cruciferous vegetable intake during the first 36 months after diagnosis was associated with a reduced risk for total mortality, breast-cancer-specific mortality, and recurrence.

They observed that across increasing quartiles of cruciferous vegetable consumption, the risk for total mortality decreased by 27% (to 62%), the risk for breast-cancer-specific mortality decreased by 22% (to 62%), and the risk for recurrence decreased by 21% (to 35%).

Population Differences

However, Dr. Nechuta cautioned that differences in the populations need to be taken into account when trying to extrapolate these results to other settings. "First, commonly consumed cruciferous vegetables in China include turnip, Chinese cabbage/bok choy, and greens, whereas broccoli and brussels sprouts are the most commonly consumed cruciferous vegetables in the United States and other Western countries," she told Medscape Medical News.

"Second, the amount of intake among Chinese women is much higher than that of American women," she continued. "The level of bioactive compounds, such as isothiocyanates and indoles, suspected of playing a role in the anticancer effects of cruciferous vegetables, depend on the amount and type of cruciferous vegetables consumed."

Future studies with direct measurements of bioactive compounds are needed to better understand the association between cruciferous vegetable intake and breast cancer outcomes, Dr. Nechuta noted.

She suggested that breast cancer survivors in the United States follow the general nutrition guidelines of eating vegetables daily, and consider increasing their intake of cruciferous vegetables, such as cabbage, cauliflower, and broccoli, as part of a healthy diet.

Chemopreventive Properties

The protective effect of cruciferous vegetables has been observed in other settings. Previous studies have reported that the intake of raw cruciferous vegetables, including broccoli, broccoli sprouts, cabbage, and cauliflower, was associated with a reduced risk for bladder cancer (Cancer Epidemiol Biomarkers Prev. 2008;17:938-944). The consumption of cruciferous vegetables might also help protect smokers from lung cancer, according to some data.

Preliminary research has shown that the consumption of broccoli sprouts can interfere with the development of gastritis and gastric cancer. In addition, consuming broccoli sprouts appears to enhance antioxidant and anti-inflammatory enzymes in the stomach, as previously reported by Medscape Medical News.

"In our 2002 study, sulforaphane killed helicobacter directly in the test tube," said Jed W. Fahey, MS, ScD, a nutritional biochemist in the Lewis B. and Dorothy Cullman Cancer Chemoprotection Center at the Johns Hopkins University School of Medicine, Baltimore, Maryland, in an interview at that time, referring to a previous study (Cancer Prev Res [Phila]. 2009;2:353-360). "It also reduced the rate of gastric cancer in mice."

"The key take-home message harkens back to the old message — eat veggies," Dr. Fahey told Medscape Medical News. "We're now giving people the science that shows why eating fruits and vegetables are good for your health."

American Association for Cancer Research (AACR) 103rd Annual Meeting: Abstract LB-322. Presented April 3, 2012.