*3.1.1 Mechanisms*

Wholegrains reduce the incidence of CRC through four mechanisms [22] by (1) the action of intestinal microbiota on dietary fibres from wholegrains in the synthesis of short-chain fatty acids, and prevents insulin resistance and serves as major source of energy (butyrate) for the colon [20], (2) phytochemicals (phenolic compounds), minerals/micronutrients, and vitamins from wholegrains have antioxidant potential capable of oxidative damage in the colon and prevents carcinogenesis [19, 20]; (3) insoluble fibre in wholegrains increases bulk of luminal contents, and dilutes potential carcinogens in the colonic epithelium to prevent colorectal carcinogenesis [23]; (4) Phytoestrogens (similar to the activities of estrogen) from wholegrains reduce risk of CRC by binding to estrogen receptors through the hormonal mechanisms [20, 21].
