Cruciferous veggies boost survival in Chinese breast cancer patients

Consuming cruciferous vegetables may 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 study of Chinese breast cancer survivors, revealed that the consumption of cruciferous vegetables after a diagnosis of breast cancer was associated with improved survival in Chinese women.

The researchers, led by Sarah J. Nechuta, MPH, PhD, a postdoctoral research fellow at Vanderbilt University in Nashville, Tennessee, discovered that cruciferous vegetable intake during the first 36 months after diagnosis boosted survival by reducing 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%).

Lifestyle differences
Dr. Nechuta cautioned that population differences must be considered in this recent study. "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 said.

"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."

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.

Anti-cancer properties
The protective effect of cruciferous vegetables is already well-known. 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.

"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," said Dr. Fahey. "We're now giving people the science that shows why eating fruits and vegetables are good for your health."

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