A study by Vanderbilt-Ingram Cancer Center and Shanghai
Center for Disease Control and Prevention investigators reveals
that breast cancer survivors who eat more cruciferous vegetables
may have improved survival. The study of women in China
was presented by postdoctoral fellow Sarah J. Nechuta, Ph.D.,
M.P.H., at the American Association for Cancer Research Annual
Meeting in Chicago, Ill.
"Breast cancer survivors can follow the general nutritional
guidelines of eating vegetables daily and may consider increasing
intake of cruciferous vegetables, such as greens, cabbage,
cauliflower and broccoli, as part of a healthy diet," said
Nechuta.
Nechuta, Xiao Ou Shu, M.D., Ph.D., and colleagues investigated the
role of cruciferous vegetables in breast cancer survival among
women in the Shanghai Breast Cancer Survival Study, a prospective
study of 4,886 Chinese breast cancer survivors who were diagnosed
with stage 1 to stage 4 breast cancer from 2002 to 2006. Shu,
Ingram Professor of Cancer Research, is the principal investigator
of the Shanghai Breast Cancer Survival Study.
After adjusting for demographics, clinical characteristics and
lifestyle factors, the researchers found cruciferous vegetable
intake during the first 36 months after breast cancer diagnosis was
associated with a reduced risk for total mortality, breast
cancer-specific mortality and disease recurrence.
Survival rates were influenced by vegetable consumption in a
dose-response pattern. As women ate more of these vegetables, their
risk of death or cancer recurrence decreased.
Women who were in the highest quartiles of intake of vegetables
per day had a 62 percent reduced risk of total mortality, 62
percent reduced risk of breast cancer mortality, and 35 percent
reduced risk of breast cancer recurrence, compared to women with
the lowest quartile of intake."
Nechuta noted that cruciferous vegetable consumption habits differ
between China and the United States and suggested this fact be
considered when generalizing these results to U.S. breast cancer
survivors.
"Commonly consumed cruciferous vegetables in China include
turnips, Chinese cabbage/bok choy and greens, while broccoli and
Brussels sprouts are the more commonly consumed cruciferous
vegetables in the United States and other Western countries," she
said. "The amount of intake among Chinese women is also much higher
than that of U.S. women."
Cruciferous vegetables contain phytochemicals known as
isothiocyanates and indoles which appear to have a protective
effect against some types of cancer.
Nechuta said the level of these bioactive compounds, proposed to
play a role in the anticancer effects of cruciferous vegetables,
depends on both the amount and type of cruciferous vegetables
consumed.
She said there is a need for future studies that measure the
bioactive compounds in these vegetables and the host factors that
may influence the effects of these compounds to improve the
understanding of the association between cruciferous vegetable
consumption and breast cancer outcomes.