h e a l t h p r o m o t i o n
Diet high in processed meat associated with poor survival from colorectal cancer
L-R: Yun Zhu, Dr. Peter Wang and Hao Wu
Research on colorectal cancer and dietary patterns shows that a diet high in processed meats is associated with worsened disease-free survival.
Research on colorectal cancer and
dietary patterns shows that a diet high in processed meats is
associated with worsened disease-free survival. The research was
carried out by an interdisciplinary research team at Memorial
University and the University of Toronto.
Dr. Peter Wang, professor of
epidemiology in the Division of Community Health and Humanities at
Memorial University’s Faculty of Medicine, is the principal
investigator of the study with graduate students Yun Zhu and Hao Wu,
master’s students and recipients of fellowships from the
Newfoundland and Labrador Centre for Applied Health Research.
The paper, Dietary Patterns and
Colorectal Cancer and Survival, was published recently in BMJ
“Dietary patterns are associated with
colorectal cancer, but little is known about their roles on survival
after a diagnosis of colorectal cancer,” explained Dr. Wang.
The study showed that disease-free
survival among colorectal cancer patients was significantly worsened
among patients with a high processed meat dietary pattern in terms
of higher risk of tumour recurrence, metastasis and death.
Colorectal cancer is the second
leading cause of cancer death in Canada and the highest incidence of
colorectal cancer and mortality rates are in Newfoundland and
Labrador. Dr. Wang noted that the diet in Newfoundland and Labrador
consists of a large proportion of processed meat, red meat and
The 529 patients in this study were
enrolled through the Newfoundland Familial Colorectal Cancer
Registry and diet was assessed using a food frequency questionnaire
which included 170 foods, beverages and supplements, plus foods such
as salted/pickled meat and smoked/pickled fish.
Three distinct dietary patterns
processed meat, prudent vegetable and high sugar—
were identified. “We found that a high intake of processed meat, red
meat, fish and processed fish is associated with decreased
disease-free survival for patients who had tumours located in the
colon and not the rectum,” said Dr. Wang.
The mechanisms explaining the impact
of red and processed meat on colorectal cancer mortality are still
unclear, said Dr. Wang. “However strong carcinogens such as N-nitroso
compounds and probably carcinogenic mutagens like heterocyclic
amines and polycyclic aromatic hydrocarbons, which have been
suggested as significant contributors for the development of
colorectal cancer, are found in smoked, fried, or high-temperature
cooked meat. Our findings between dietary patterns and colorectal
cancer survival may also be explained by the impact of dietary
patterns on gut microflora on health outcomes.”
This study showed that the influence
of processed meat pattern on survival was evident among women rather
than men. Dr. Wang noted that the BRAF gene mutation in women is
found to be significantly associated with poor colorectal cancer
survival, but further research is needed in this area.