SAN ANTONIOA randomized dietary intervention study of 3,100 breast cancer survivors requires the study group to eat five vegetable servings and 16 oz of vegetable juice daily, a level of vegetable intake that has not previously been examined. By comparison, the women in the control group are following the National Cancer Institute (NCI) diet, which includes only three vegetable servings and no vegetable juice.
The Women’s Healthy Eating and Living (WHEL) study is examining the effects of a diet rich in vegetables, fruit, and fiber on the health of breast cancer survivors, including cancer recurrences.
Despite the high level of vegetables required, participants in the study have been able to change their diet and maintain the change for more than 4 years, said Vicky E. Jones, MD, associate professor of medicine, University of California, San Diego, Cancer Center.
To confirm the dietary changes, investigators measured blood compounds, including beta-carotene, alpha-carotene, and lutein levels. "These blood levels substantiate that the participants are making major changes in their vegetable intake, something that has not been accomplished in any of the other dietary intervention studies to date," Dr. Jones said.
The study participants also completed food frequency questionnaires and 24-hour dietary recalls, Dr. Jones said at a poster session of the 23rd Annual San Antonio Breast Cancer Symposium.
"This population is very motivated," Dr. Jones told ONI. Even before enrollment in the study, many of the women had already added more vegetables and fruits to their diet to meet the NCI recommendations, she said. The NCI daily diet includes two fruit servings, three vegetable servings, 20 g of fiber, and less than 30% of energy from fat. The WHEL diet requires three fruit servings, five vegetable servings, 16 oz of vegetable juice, 30 g of fiber, and 20% of energy from fat.
To encourage and promote the dietary changes, trained nutrition counselors make regular phone calls to the study participants. The study also sponsors cooking classes so that the women can learn new ways to prepare food to meet their vegetable and fruit requirements.
Enrollment was opened in 1995 and completed Nov. 30, 2000, Dr. Jones said. Eligible women had stage I (tumor 1 cm or larger), stage II, or stage IIIA tumors; diagnosis within 4 years of randomization; and no current chemotherapy.
To date, there have been approximately 200 relapses and 58 deaths. It is too early to evaluate outcome, she said.