Co-consumption of Vegetables and Fruit, Whole Grains, and Fiber Reduces the Cancer Risk of Red and Processed Meat in a Large Prospective Cohort of Adults from Alberta's Tomorrow Project.
Level 3 - non-randomized controlled study
Prospective cohort study with registry linkage
PubMed 32751091 · doi:10.3390/nu12082265
What was done
Researchers evaluated 26,218 adults aged 35-69 years enrolled in Alberta's Tomorrow Project. Baseline diet was measured using a 124-item past-year food frequency questionnaire. Incident cases of all-cause cancer and 15 specific cancers linked to red and processed meat were tracked through cancer registry linkage over an average follow-up of 13.5 years. Competing risk Cox proportional hazards and accelerated failure time models examined combinations of meat intake with vegetables and fruit, whole grains, and fiber while adjusting for mortality and established confounders.
What was found
Compared to high vegetable and fruit intake combined with low processed meat intake, low vegetable and fruit intake combined with high processed meat was associated with higher incidence of all-cause cancer (men: HR = 1.85; women: HR = 1.44) and 15 meat-linked cancers (men: HR = 1.91; women: HR = 1.49). This combination also accelerated time-to-cancer occurrence by 6.5 and 7.1 years in men and 5.6 and 6.3 years in women for all-cause and 15 cancers, respectively. Associations were less pronounced and less consistent for whole grains, fiber, and red meat.
Why it matters
This study provides evidence that dietary co-consumption patterns matter, indicating that adequate fruit and vegetable intake may counteract some of the elevated cancer risks linked to processed meat.
Limits
Dietary intake was measured only once at baseline using a self-reported food frequency questionnaire, which is susceptible to recall bias and does not account for dietary changes over 13.5 years of follow-up. The observational design cannot establish causality or fully exclude residual confounding.
Cited by
- partial A Canadian cohort study by Maximova examining tertiles of unprocessed red meat and fruit/vegetable intake found that red meat had a negative impact on cancer at low fruit and vegetable intake, but at high fruit and vegetable intake combined with high red meat intake, there was a protective effect on cancer with a relative risk of approximately 0.78.