Since ADH1B rs1229984 has a large effect on alcohol drinking behaviors, many studies have investigated its association with additional phenotypes. Due to its role in liver detoxification, the ADH1B protective allele was tested with respect to alcoholic liver disease in multiple independent candidate gene studies, and our meta-analysis confirmed its strong association [Li and others 2011a]. However, a large study conducted in cohorts (N = 9,080) from the Copenhagen City Heart Study showed that ADH1B rs1229984 genotypes were not associated with and did not modify the effect of alcohol on biochemical tests or risk of liver disease [Tolstrup and others 2009]. The same study cohort was also used to conduct a large Mendelian-randomization study (N = 54,604) to estimate the causal effects of long-term alcohol consumption on coronary heart disease risk factors [Lawlor and others 2013]. The authors observed effects of long-term alcohol consumption, calculated on the basis of ADH1B genotype (instrumental variable), on blood pressure, body mass index (BMI), and triglyceride levels [Lawlor and others 2013]. A larger Mendelian-randomization study (N = 261,991) replicated these results, reporting that the
