There is overwhelming evidence, both biochemical and genetic, that ALDH2*2 reduces alcohol consumption, particularly heavy drinking, and greatly reduces the risk for AD, through its triggering of a strong flushing reaction. Reports of association of other genes on chromosome 12 within 1 – 2 Mb of ALDH2 in populations in which ALDH2*2 is present are nearly certain to be due to strong LD with this functional variant (Supplementary Figure 3), and the evidence for effects of the other variants disappears when conditioned on rs671. Evidence for association of ALDH1A1 and ALDH1B1 is very weak.
