# In-depth Biological Monitoring to Estimate Effects of Red or Processed Meat on Colorectal Cancer

## TL;DR

This study investigates how red or processed meat affects colorectal cancer in Koreans, finding limited direct impact despite associated biomarkers.

## Contribution

The study provides in-depth biological monitoring linking meat consumption to oxidative stress biomarkers but finds no strong link to CRC prevalence in a low-meat-consuming population.

## Key findings

- CRC presence was associated with lifestyle factors like sex, BMI, and cooking methods, not meat intake.
- Biomarkers like MDA, 1-OHP, MeIQx, and PhIP were interrelated but not elevated in CRC patients.
- Oxidative stress from meat may exist, but it does not significantly affect CRC prevalence in low-meat-consuming Koreans.

## Abstract

Background: The intake of red or processed meat remains controversial as a crucial factor for CRC. Thus, we performed in-depth biological monitoring.

Methods: We performed a case- control study and analyzed various exposure and response biomarkers including 1-OHP, MeIQx, and PhIP, and malondialdehyde (MDA), and heterocyclic amine (HCA)-DNA adducts in Korean cases and controls (N = 218).

Results: They consumed 53.4 ± 74.0 g/day of red meat and 1.1 ± 3.7 g/day of processed meat. The CRC presence was associated with sex, BMI, tobacco smoking, alcohol drinking, cooking method of meat, and vegetable consumption, rather than red or processed meat intake. The levels of MDA were positively associated with those of 1-OHP, MeIQx, or PhIP. The sum of 1-OHP, MeIQx, and PhIP was associated with the levels of HCA-DNA adducts and cooking method of meat. In addition, the above biomarkers for CRC were associated with each other. However, most of these biomarkers were not higher in CRC patients than those in controls.

Conclusion: The present in-depth biological monitoring provides that red or processed meat may induce oxidative stress; however, present intake of the meat and the intake-related oxidative stress may not affect CRC prevalence among the Korean population, who consume less meat than Westerners.