Cabbage-Family Vegetables May Reduce Cancer Risk

Including Chinese stir-fries in your family's diet could help reduce their risk for cancer.

"Vegetables in the cabbage family like Chinese bok choy contain protective phytochemicals called glucosinolates that help the body eliminate carcinogens," said Dr. Janice Stuff, an assistant professor at Baylor College of Medicine and a CNRC nutrition scientist.

According to Stuff, the traditional Asian diet is rich in cabbage-family vegetables, also called cruciferous vegetables, and contains nearly three times the level of protective glucosinolates as the typical American diet.

"Research suggests that consuming just two servings a day of cruciferous vegetables could cut the risk for certain types of cancer, including prostate and esophageal cancers, by nearly 50 percent," she said. Other cruciferous vegetables include broccoli and broccoli sprouts, Brussels sprouts, horseradish, mustard greens, collard greens, cauliflower, cabbage, horseradish, kohlrabi, rutabaga, watercress, and Japanese wasabi.

Scientists have been exploring the link between diet and reduced risk for certain cancers for more than thirty years. In early studies, epidemiologists found that men living in Japan and China not only had much less prostate cancer than American men, they also had less than Chinese and Japanese men who emigrated to America and much less than second- and third-generation Chinese- and Japanese-Americans. Similar trends were found in breast-cancer rates among women.

"Since genetic makeup doesn't change when someone emigrates to a new country, it's clear that some environmental factor or factors, such as dietary changes, were affecting cancer rates," Stuff said.

Recent research linking the intake of specific foods to cancer risk found that vegetables, particularly cruciferous vegetables, had pronounced anti-cancer benefits. Further laboratory tests found that glucosinolates, which give cruciferous vegetables their bitter taste, stimulated the body to produce enzymes that help prevent prostate and other cancer.

Although studies continue to confirm that diet can play a significant role in cancer risk, this doesn't mean that genetic makeup doesn't matter. Stuff points out that genetic makeup can affect how effectively and/or efficiently an individual's body responds to the presence of glucosinolates in the diet, which in turn can affect cancer risk.

"This is what makes nutrition research in the post-human genome sequencing era exciting. Perhaps one day we will find genetic markers that identify those individuals who could benefit most from increasing their consumption of cruciferous vegetables or other anti-cancer food," she said.

Stuff, like many nutrition researchers, also believes that cancer prevention, like the prevention of many diseases that tend to appear later in life, should begin in childhood.

"As a pediatric nutrition researcher, I am very interested in understanding whether the consumption of cruciferous vegetables in childhood can affect life-long cancer risk, and if so, the amount that is beneficial," she said.

Editor's Note: See www.leafygreens.org for information and lesson plans featuring nutritious greens.  For more information on food and cancer prevention, see the American Cancer Society web site:  www.cancer.org.