Folate

Suggested

2 studies · 1 recommendation

Last updated: February 21, 2026

Suggested2 studies

Adequate dietary folate intake linked to meaningful reduction in colorectal cancer risk

Two case-control studies totaling over 2,786 participants consistently demonstrate that higher dietary folate intake lowers colorectal cancer risk. In a large Italian-Swiss network analyzing 2,390 colorectal cancer cases, each 100μg/day increase in dietary folate reduced risk by 17% (OR: 0.83). A Portuguese study of 396 participants found high folate intake (>406.7 μg/d) associated with a 33% risk reduction (OR: 0.67; 95% CI: 0.45–0.99), with folate intake significantly lower among cancer patients (P = 0.02). Notably, individuals with the MTHFR C677T TT genotype and low folate intake faced a dramatically elevated risk (OR: 14.0), highlighting a critical gene-nutrient interaction. Both studies adjusted for major confounders including sex, age, smoking, and alcohol consumption, with consistent protective effects across demographic subgroups.

Evidence

Dietary folates and cancer risk in a network of case-control studies

Authors: Dal Maso, L., Franceschi, S., La Vecchia, C., Levi, F., Malerba, S., Montella, M., Pelucchi, C., Serraino, D., Tavani, A., Zambon, A., Zucchetto, A.

Published: August 2, 2017

A large network of case-control studies conducted in Italy and Switzerland (1991-2009) analyzed 2390 colorectal cancer cases. Each 100μg/day increment in dietary folate intake was associated with an odds ratio of 0.83, indicating a 17% reduction in colorectal cancer risk. This was one of the largest case series in the study. Multiple logistic regression models adjusted for major confounding factors were used to estimate risk. No material heterogeneity was observed across strata of sex, age, smoking, and alcohol drinking habits.

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Risk of colorectal cancer associated with the C677T polymorphism in 5,10-methylenetetrahydrofolate reductase in Portuguese patients depends on the intake of methyl-donor nutrients

Authors: Brito, Miguel, Carmona, Bruno, Carolino, Elisabete, Cravo, Marília, Fidalgo, Paulo, Gonçalves, Susana, Guerreiro, Catarina Sousa, Leitão, Carlos Nobre

Published: November 1, 2008

In a case-control study of 196 colorectal cancer patients and 200 age- and sex-matched healthy controls in Portugal, folate intake was significantly lower in cancer patients (P = 0.02). High folate intake (>406.7 μg/d) was associated with a 33% reduced risk of colorectal cancer (OR: 0.67; 95% CI: 0.45, 0.99). Among individuals homozygous for the C677T MTHFR polymorphism (TT genotype), low folate intake dramatically increased colorectal cancer risk (OR: 14.0; 95% CI: 1.8, 108.5), representing a statistically significant gene-nutrient interaction. The TT genotype alone conferred a 3.0-fold increased risk (95% CI: 1.3, 6.7).

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