Alcohol consumption-induced global DNA methylation changes were examined in healthy individuals by Zhu et al.,48 who examined the impact of alcohol drinking on Alu or LINE-1 methylation (quantified by PCR-pyrosequencing) in blood DNAs of 1,465 healthy subjects. They found an inverse correlation between alcohol drinking with methylation of Alu (but not LINE-1). In contrast, two other studies, one with 161 healthy control subjects52 and another with 384 healthy women,53 failed to identify a significant effect of alcohol drinking on global methylation of blood DNAs. Additionally, Manzardo et al.40 examined global DNA methylation patterns in postmortem frontal cortex tissues of 10 AUD patients and 10 matched controls using methylation DNA immunoprecipitation (MeDIP) and microarray assays, but no significant global DNA methylation differences between AUD patients and control subjects were observed.
