Study investigates the association between iron consumption and the incidence of colorectal, colon, and rectal cancer in South Korea.
Study
Study participants were recruited from the Korean Genome and Epidemiology Study’s Health Examinees (KoGES HEXA) study, which included a large-scale population-based cohort. Individuals 40 years of age and younger, as well as those who were 69 years or older, were excluded from the analysis. Any individual with missing mortality, cancer-related, or incomplete dietary data were not considered.
At baseline, information about the participants’ dietary pattern, daily food intake quantity, and types of food consumed were obtained through a semi-quantitative food frequency questionnaire (FFQ). The dietary iron content for each food item was obtained from the KoGES HEXA FFQ database.
Total and non-heme iron intake were classified by quintiles (Q) to ensure the statistical significance of each group. Notably, heme iron was categorized into quintiles due to the insufficient number of observations for absolute levels of heme iron intake.
The number of CRC cases was obtained from the Korea Central Cancer Registry.
Results
A total of 109,908 individuals with a mean age of 53.8 years were followed up for 9.1 years. During the follow-up period, 608 new cases of CRC were recorded, which reflected an incidence of 60.5 CRC cases for every 100,000 person-years.
Complex associations between iron intake and colorectal, colon, and rectal cancer were observed. Men, younger individuals, those with high body mass index (BMI), with a history of smoking or drinking, and those with higher levels of education consumed the most amount of iron ranging from 9.49-47.53 mg/Day (Q5), as compared to 1.09-4.97 (Q1).
Study participants in Q1 were more likely to be physically inactive, have a history of diabetes hypertension, or a family history of CRC as compared to those in Q5. The total energy consumption was higher in Q5.
Total daily iron consumption in Q2 was associated with a significantly lower risk of CRC and colon cancer as compared to Q1. However, no significant association between rectal cancer and total iron consumption was observed.
Among men, Q2 participants were significantly less likely to be diagnosed with lower CRC and colon cancer as compared to those in Q1. Among women, the results were statistically insignificant; however, the risk of these cancers was also the lowest in Q2.
Heme iron did not exhibit a linear trend nor significantly affect CRC and colon cancer risk. Relative to Q1, a reduced risk of rectal cancer was observed in Q4; however, these results were not statistically significant. As compared to Q1, significantly lower CRC and colon cancer risk were observed in the Q2 group for non-heme iron consumption.
Nonsignificant associations between non-heme iron consumption and rectal cancer were observed. Men in the Q2 group were significantly less likely to develop colon cancer and CRC as compared to Q1; yet, this association was not observed for rectal cancer.
Conclusion
CRC and colon cancer risk is reduced by high total and non-heme iron consumption in a population of Korean individuals. Future research is needed to elucidate the mechanisms involved in this association and the impact of diet in modulating cancer risk.
Source:
https://www.news-medical.net/news/20250414/Moderate-iron-intake-linked-to-lower-colon-cancer-risk.aspx