Folate status and colorectal cancer risk: A 2016 update

Abstract

The consensus of epidemiologic evidence indicates that an abundant intake of foodstuffs rich in folate conveys protection against the development of colorectal cancer, and perhaps some other common cancers as well. Pre-clinical models substantiate that the relationship is a genuinely causal one. Pre-clinical models have also lent mechanistic insights into the biochemical and molecular pathways by which adequate folate exposure conveys these protective effects, and human studies are beginning to confirm the relevance of this mechanistic understanding to human cancer biology. Enhancement of genetic stability appears to be a major mechanism by which folate sufficiency protects against carcinogenesis. To date, the Wnt signaling cascade has been the pathway most examined in this regard. The relationship between folate exposure and colorectal cancer risk is a complex one, in part because a number of extrinsic and intrinsic factors act as effect modifiers. This review discusses how the intake of the other three B-vitamins integral to the 1-carbon pathway acts as one such effect modifier. In addition, two concepts that remain matters of considerable debate are whether parental intake of folate impacts on subsequent cancer risk in the offspring, and whether excessive intakes of folate may have a paradoxical cancer-promoting effect: observations underlying these two concepts are presented as well.

Gastric microbes associated with gastric inflammation, atrophy and intestinal metaplasia 1 year afterHelicobacter pylorieradication

“…Folate biosynthesis by the gut microbiota is a source of the water-soluble tetrahydrofolates which play an essential role in human metabolism 47. Inadequate status of folate has been implicated in increased risk of colon cancer especially if precancerous lesions exist 48. This may be applicable to gastric carcinogenesis, given our observation in this study.…”

“…This may be applicable to gastric carcinogenesis, given our observation in this study. Optimisation of bacterial production of folate may reduce the risk of IM development 48. Nucleotide oligomerisation domain containing proteins (NOD) are conserved pattern recognition receptors that are stimulated by pathogen-associated molecular patterns (PAMPS).…”

Wild edible plants: Nutritional and toxicological characteristics, retrieval strategies and importance for today's society

“…Folates are essential for various physiological and developmental functions in the human body (Saini et al, 2016). They are critical for the embryonic development (Kim et al, 2009) and inadequate intakes may result in higher risk of certain cancers (Mason and Tang, 2016). Therefore, since humans cannot synthesize this vitamin, its intake needs to be ensured from dietary sources.…”

One‐carbon metabolite ratios as functional B‐vitamin markers and in relation to colorectal cancer risk

“…Studying one‐carbon metabolites individually may give ambiguous results, due to the interdependence between the metabolites . We have previously used a machine learning‐based Bayesian network approach to simultaneously study >30 factors involved in one‐carbon metabolism in relation to CRC risk .…”

“…24,27,28 Studying one-carbon metabolites individually may give ambiguous results, due to the interdependence between the metabolites. 29 We have previously used a machine learningbased Bayesian network approach to simultaneously study >30 factors involved in one-carbon metabolism in relation to CRC risk. 18 The study confirmed the importance of folate, riboflavin and PLP relative to other metabolites involved in one-carbon metabolism.…”