Are Dietary Patterns Linked to Survival in Patients With Colorectal Cancer?
Posted: Wednesday, December 19, 2018
Diets with more plant- and less animal-based foods, with more fiber and less added sugar, before and after diagnosis of colorectal cancer may be associated with longer survival, concluded Mark A. Guinter, PhD, MPH, of the American Cancer Society (ACS), and colleagues. These investigators analyzed a sector of the large Cancer Prevention Study-II Nutrition Cohort, followed for more than 20 years, and their findings were reported in the Journal of Clinical Oncology.
The prospective study evaluated the association of diet quality both prediagnosis and postdiagnosis with the risk of mortality. The investigators centered on data from 2,801 individuals included in the cohort who were cancer-free at baseline (1992–1993) but developed invasive, nonmetastatic colorectal cancer between then and June 2013.
Four patient dietary patterns were compared. The first one was the Western diet, which is characterized “by high intake of refined grains, red and processed meats, eggs, solid fats, and salty snacks,” the team stated. The other three included the ACS nutrition guidelines, DASH (Dietary Approaches to Stop Hypertension) score, and prudent pattern score; they all emphasize fruits, vegetables, whole versus processed grains, and lower-fat sources of protein.
The postdiagnosis patients with colorectal cancer who most closely followed ACS-recommended dietary guidelines had “a 65% lower risk of [colorectal cancer] mortality and a 41% lower risk of mortality as a result of all other remaining causes combined,” compared with those who followed the ACS guidelines the least. Additionally, “for the highest quartile of prediagnosis [patients who followed the] Western dietary pattern, there was a 30% higher risk of death compared with the lowest quartile.”
“Consistently observed inverse associations suggest that prognosis may improve with better postdiagnosis diet, even when prediagnosis diet quality was relatively low,” Dr. Guinter and colleagues noted.