Mechanistic Hypotheses on Colorectal Cancer and Red Meat Intake: A Review

Abstract

Red meat is classified as probably carcinogenic to humans by International Agency for Research on Cancer (IARC) based on evidence on how it may affect the development of colorectal cancer, the third most common cancer worldwide. A plethora of scientific experiments prevailing to establish a positive association between red meat and colorectal cancer suggested different mechanistic hypotheses in order to explain such a phenomenon. This paper aims to discuss major hypotheses related to how red meat consumption may lead to colorectal cancer. Such hypotheses involve the role of natural compounds present in red meat (such as lipid, protein, N-glycolylneuraminic acid and heme iron) and neoformed substances during meat processing (such as heterocyclic amines, polyaromatic hydrocarbons and N-nitroso compounds).

Red Meat Heating Processes, Toxic Compounds Production and Nutritional Parameters Changes: What about Risk–Benefit?

“…The oil type also influences the increase in contaminants after heating processes, as in the case of HAAs, the formation of which is directly proportional to the level of saturated fatty acids [61]. Quantifiable levels of some NAs, namely, N-Nitrosodiethylamine, N-Nitrosodimethylamine, N-Nitrosomethylethylamine, N-Nitrosopiperidine and N-Nitrosomorpholine, in the range 0.1-0.7 µg kg −1 , were also reported by different authors in several oil types, such as olive oil, grapeseed, sunflower, perilla, sesame, rape, soybean, corn and peanut [23][24][25][26]30,[45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60][61][62]. Regarding acrylamide, most studies were focused on meat heating processes by frying, confirming the possible formation of such a contaminant up to 129 µg kg −1 .…”

“…It is well-known that red meat has been classified as probably carcinogenic to humans (by IARC), and this food safety aspect relies on inherent characteristics of food matrices, such as the presence of heme iron mediating lipid peroxidation, neuraminic acid, etc. [57][58][59], but also on heat processing, which leads to the formation of several toxic compounds. Based on the consulted literature about the role of meat heating processes on the production of contaminants, such as HAAs, NAs, PAHs and acrylamide, the effect of meat heating processes on the number and level of these molecules was highlighted.…”

Kimchi exerts chemopreventive potential against colorectal carcinogenesis associated with red meat intake

“…Oxidation and formation of free radicals are suggested to be one of the early events transforming normal colon cells into precancerous ones since these phenomena could lead to mutation and genetic impairment [38]. Heme iron present in red meat is a potent prooxidant that could provoke oxidation in colonic environment [39]. Antioxidants in kimchi are expected to counteract iron-driven oxidation in the context of red meat consumption.…”

Chemopreventive potential of kimchi, an ethnic food from Korea, against colorectal carcinogenesis associated with red meat intake

“…Oxidation and formation of free radicals are suggested to be one of the early events transforming normal colon cells into precancerous ones since these phenomena could lead to mutation and genetic impairment [38]. Heme iron present in red meat is a potent prooxidant that could provoke oxidation in colonic environment [39]. Antioxidants in kimchi are expected to counteract iron-driven oxidation in the context of red meat consumption.…”