**9.1.6 Alcohol**

We believe that chronic alcohol abuse is a major risk factor for gastrointestinal polyps and cancer formation in esophagus, stomach, colon and rectum. High alcohol intake (>21 units/week) of beer, wine and spirits significantly increases the risk for CRP and CRC. These findings are probably due to the effect of acetaldehyde, which damages colorectal mucosa and elevates cell regeneration. Folic acid and methionine deficiency in persons who chronically abuse with alcohol are also risk factors for development of CRC (Giovannucci et al., 1995). Alcohol is an inducer of cytochrome P-405 2E1, which contributes to increased production of free radicals (Seitz & Osswald, 1992). Alcohol diminishes the transformation of retinol into retinoic acid and as result cell proliferation is upregulated (Seitz et al., 1998).
