Meta-analyses of ALDH2 and ADH1B with alcohol dependence in Asians.

Abstract

Meta-analyses were conducted to determine the magnitude of relationships between polymorphisms in 2 genes, ALDH2 and ADH1B, with alcohol dependence in Asians. For each gene, possession of 1 variant *2 allele was protective against alcohol dependence, and possession of a 2nd *2 allele did not offer significant additional protection. The protective effects of these 2 gene polymorphisms were independent. Diagnostic criteria, recruitment strategy, and Japanese ethnicity moderated the effect of ALDH2*2. Recruitment strategy and gender moderated the effect of ADH1B*2. These findings highlight the importance of methodological issues and potential gene-gene and gene-environment interactions that must be considered when examining relationships between genetic polymorphisms and phenotypes.

ALDH2*2 and peer drinking in East Asian college students

“…The frequency midpoints (shown in parenthesis), based on a month with 30 days, were never (0), monthly or less (0.5), 2 to 4 times a month (3), 2 to 3 times a week (10.7), and 4 or more times a week (23.54). The quantity midpoints (shown in parentheses) were 1–2 (1.5), 3–4 (3.5), 5–6 (5.5), 7–9 (8), and 10 or more (15.5) (27). …”

“…Alcohol-related flushing occurs when a deficient enzyme, for metabolizing acetaldehyde, the primary metabolite of alcohol, to acetate, results in a buildup of acetaldehyde in the body (6). Studies show that individuals who carry ALDH2 *2 drink less frequently, consume smaller quantities of alcohol, and have a reduced risk for alcohol dependence (2,7,8). …”

Genetic and Environmental Predictors of Alcohol Use in Asian American Young Adults

“…Studies have linked increased acetaldehyde levels to a heightened physiological response to alcohol, characterized by a flushing response and tachycardia (Hendershot et al, 2009a;Wall, 2005). Consequently, compared with ALDH2*1 homozygotes, ALDH2 heterozygotes are about one fourth as likely to develop alcohol dependence, and *2 homozygotes have effectively no risk (Luczak et al, 2006). ALDH2*2 has also been linked to significant reductions in heavy episodic drinking (Luczak et al, 2001;Wall et al, 2001).…”

“…The theoretical mechanism of action for ADH1B is that the *2 allele codes for a more potent ADH enzyme, which results in an increase in acetaldehyde levels (Luczak et al, 2006;Wall, 2005). As is the case with ALDH2*2, elevated levels of acetaldehyde as a result of ADH1B*2 will theoretically predict lower alcohol consumption.…”

Genetics: No more addictive personality

“…A 2006 meta-analysis of 15 studies included 4,500 Chinese, Japanese, Korean and Thai participants who were tested for genes related to the metabolism of acetaldehyde and acetate. The largest protective factor was the ALDH2 variant, which makes people nine times less likely to develop alcoholism than those with other variants of the gene 3 .…”