Aims: The stomach is involved in first-pass metabolism of alcohol in humans. As conflicting data were published regarding the influence of age and gender on the activity of alcohol dehydrogenase (ADH) in human gastric mucosa, the present study aimed at the investigation of these and other potentially confounding factors (alcohol consumption, smoking, drug intake) on its activity in a Caucasian population. 

Methods: ADH activity was assessed in endoscopic gastric biopsy specimens from 111 Caucasian subjects aged 20-80 years, of whom 51 were females. 

Results: Highest ADH activity was measured at ethanol concentrations between 150 and 500 mM. Mean ADH activity was higher in antral specimens than in those from the gastric corpus of the same subjects. ADH activity decreased with increasing age in males, while the values in females aged 41-60 years were higher than those in women aged 20-40 or 61-80 years. In men aged 20-40 years, consumption of larger quantities of alcohol (>0.8 g/kg body weight/day) was associated with reduced ADH activity. H₂-Receptor antagonist treatment also decreased gastric ADH activity. 

Conclusions: The results indicate that ADH activity in human gastric mucosa is negatively associated with consumption of larger quantities of alcohol. The question of whether ADH activity is higher in males or females can only be answered with respect to age. The gastric ADH activity in young men is distinctly higher compared to young women, but the opposite holds true in middle-aged subjects.