Genetic variation in aldehyde dehydrogenase 2 and the effect of alcohol consumption on cholesterol levels

Moderate drinkers with a defective alcohol dehydrogenase type 3 (ADH3) genotype have higher high-density lipoprotein (HDL) levels and a decreased risk of coronary artery disease (CAD). We examined the interaction between the aldehyde dehydrogenase type 2 (ALDH2), alcohol intake, and HDL levels in 826 men and 1295 women in a rural town in Japan. The ALDH2 genotype of each subject was determined by polymerase chain reaction (PCR) analysis. HDL was adjusted for the alcohol intake, age, body mass index, smoking status, total cholesterol, triglycerides and HbA1c levels. None of the subjects had a history or ECG suggestive of CAD. The proportions of ALDH2, *1/*1, *1/*2, and *2/*2 (defective homozygote) were 45.8, 46.0, and 8.2%, respectively, for men. Drinking more than two drinks daily was associated with lower HDL levels in men with the defective genotypes compared with men with a normal genotype (55.6±0.9 vs. 51.2±0.9 mg/dl, mean±S.E., P<0.0001). Also, drinking more than 0.5 drinks daily was not associated with beneficial effects on HDL levels in women with defective ALDH2 genotypes. Conclusions: Alcohol intake did not have beneficial effects on HDL levels in the defective ALDH2 genotype and may not protect against CAD in subjects with defective ALDH2 genotypes.