Diet High in Meat, Fat, and Refined Grains Is Associated With Increased Risk for Colon Cancer Recurrence and Death

Abstract

Patients treated for colon cancer who consumed a diet high in meat, refined grains, fat, and desserts had an increased risk of cancer recurrence and death compared with patients who consumed a diet high in fruits and vegetables, poultry, and fish, according to a study in the August 15, 2007 issue of The Journal of the American Medical Association. Previous research has indicated that diet and other lifestyle factors have a significant influence on the risk of developing colon cancer. However, few studies have assessed the influence of diet on colon cancer recurrence and survival, according to researchers led by Dr. Jeffrey A. Meyerhardt, MD, MPH, of the Dana-Farber Cancer Institute, Boston, MA. “This is the first study, to our knowledge, in a potentially cured population of colon cancer survivors to address the effect of diet,” they write. Meyerhardt et al examined the influence of 2 distinct dietary patterns on cancer recurrence and survival in a group of 1009 stage III colon cancer patients enrolled in a clinical trial of postoperative chemotherapy in addition to other treatment. Patients reported dietary intake using a food frequency questionnaire during and 6 months after supplemental chemotherapy. Two major dietary patterns were identified: “prudent” and “Western.” The prudent pattern was characterized by high intakes of fruits and vegetables, poultry, and fish, whereas the Western pattern was characterized by high intakes of meat, fat, refined grains, and dessert. During a median follow-up of 5.3 years, 324 patients had cancer recurrence, 223 patients died with cancer recurrence, and 28 died without documented cancer recurrence. The researchers found that intake of a Western dietary pattern after cancer diagnosis was associated with a significant increase in the risk of cancer recurrence or death. Compared with patients in the lowest Western dietary pattern quintile (bottom 20%), those in the highest quintile (top 20%) experienced a 3.3 times higher risk for cancer recurrence or death. Patients in the highest quintile of Western dietary pattern were 2.9 times more likely to have their cancer recur than those in the lowest quintile. Similarly, a significantly higher overall risk of death with increasing Western dietary pattern was observed. In contrast, the prudent dietary pattern was not significantly associated with cancer recurrence or death. “Studies have shown an improved disease-free survival among patients who receive adjuvant chemotherapy following the surgical resection of stage III colon cancer,” the researchers write. “Because this was an observational study, causality cannot and should not be drawn from these data. Nonetheless, the data suggest that a diet characterized by higher intakes of red and processed meats, sweets and desserts, french fries, and refined grains increases the risk of cancer recurrence and decreases survival. Further analyses are under way to better delineate specific nutrients or food groupings that may have the strongest association,” the authors write. See JAMA “Association of Dietary Patterns with Cancer Recurrence and Survival in Patients with Stage III Colon Cancer.” 2007;298:754–764.