Study Finds That Cruciferous Vegetables May Reduce Risk
A team of Roswell Park researchers that includes an ambitious high school student has given women everywhere another good reason to eat their veggies. Findings of their study, which was published in the journal Nutrition and Cancer, suggest that women who eat more vegetables – specifically cruciferous vegetables – have a reduced risk of developing ovarian cancer, a relatively rare but often deadly disease.
This year alone, about 22,000 American women will be diagnosed with ovarian cancer, and more than half of these women will die of the disease within 5 years. Ovarian cancer remains a leading cause of cancer-related deaths, because most cases aren’t caught and treated until an advanced stage. No screening methods are available to detect ovarian cancer at the earlier, more treatable stages of the disease, and symptoms (such as bloating, pelvic or abdominal pain, difficulty eating, or feeling full quickly) are vague and nonspecific.
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A few years ago, Hallie McManus, a science-minded high school student from Chappaqua, NY, decided to join the search for ways to prevent this deadly disease. Believing that a diet rich in vegetables might offer protection against ovarian and other types of cancer, Hallie reached out to Susan McCann, PhD, RD, Professor of Oncology in the Department of Cancer Prevention and Control at Roswell Park Comprehensive Cancer Institute, to see if she would act as a mentor.
Impressed by Hallie’s drive and determination, Dr. McCann encouraged her to join Roswell Park’s Summer Cancer Research Experience Program for High School Students. She did, and during her time at Roswell Park, Hallie — along with Dr. McCann and other researchers in the Department of Cancer Prevention and Control — analyzed data from the Patient Epidemiology Data System (PEDS), which contains a variety of information about patients with suspected cancer who came to Roswell Park for further evaluation between 1981 and 1998.
All patients were asked to complete a survey with 44 questions about diet, including how often they ate cruciferous vegetables (such as broccoli, cauliflower, cabbage and kale). Among patients who filled out and returned the food-frequency questionnaire, the team selected 675 women who were diagnosed with ovarian cancer and 1275 women who were diagnosed with a benign (noncancerous) condition. The researchers then compared diet and cruciferous vegetable intake in the few years before diagnosis between these two groups of women, who were matched for such important variables as age and reproductive history.
Dr. McCann and her team found that the women who ate a lot of cruciferous vegetables — especially cooked cauliflower and cooked greens (such as kale, mustard greens and collard greens) — had a lower risk of ovarian cancer. What’s more impressive is that women who ate the most vegetables had the lowest odds of ovarian cancer, and the reduction in risk seemed to improve with every 10 servings of cruciferous vegetables eaten per month. Women who ate more vegetables of any kind had a 40% reduced risk of ovarian cancer.
“We have much more to learn about the relationship between dietary choices and cancer,” says Dr. McCann. “All cancers are multifactorial diseases, meaning that many different things contribute to it. But this study does suggest that cruciferous vegetable consumption could help reduce the risk of ovarian cancer. It certainly wouldn’t hurt.”
Cruciferous vegetables belong to the Cruciferae family, which are cool-weather plants that bear flowers with four petals assembled in the shape of a cross (or crucifix). The most common and widely available cruciferous vegetables include:
- Bok choi (pak choi)
- Brussels sprouts
- Collard greens
- Mustard (seeds and leaves)
Cruciferous vegetables contain high levels of phytochemicals called glycosinolates, which, when broken down by chopping, cooking and chewing, are converted to isothiocyanates. Several studies have shown that isothiocyanates prevent the development of several types of cancer in many ways — for example, by inhibiting the growth of tumors and eliminating carcinogens from the body. Cruciferous vegetables have also been shown to reduce inflammation, which can help prevent cancer and several other diseases, including heart disease.
Overall, the study suggests that a healthy diet that includes cruciferous vegetables may decrease a woman’s risk of developing ovarian cancer. If you’re not used to eating these types of vegetables, here are some delicious recipes to get you started:
- Arugula salad with homemade balsamic vinaigrette
- Steamed broccoli with olive oil, garlic, and lemon
- Cauliflower “mac and cheese”
- Roasted parsnips turnips, and rutabagas with ancho-spiced honey glaze*
*If you can’t find ancho chilies, use regular chili powder instead. For more heat, add a pinch of crushed red pepper flakes or a dash of your favorite hot sauce.