Effect of alcohol consumption on hepatic aldehyde dehydrogenase activity in alcoholic patients

Two liver biopsies were performed 6 months apart in each of 29 patients with alcoholic liver disease. Hepatic aldehyde dehydrogenase activity was measured on each occasion. The patients were seen regularly and their alcohol consumption was assessed independently. Hepatic aldehyde dehydrogenase activity was unchanged in 17 patients who continued to drink to excess; it rose in 10 patients who significantly reduced their alcohol intake; and it fell dramatically in 2 patients who were virtually abstinent initially, but then began drinking heavily. These results clearly demonstrate that alcohol consumption itself depresses hepatic aldehyde dehydrogenase activity. It is unlikely that the low hepatic aldehyde dehydrogenase activity reported in alcoholics represents a primary abnormality predisposing to alcoholism or alcoholic liver disease.