Background: There is a paucity of detailed and controlled studies on the action of ethanol and alcoholic beverages on gastric emptying in humans. This study was designed to compare the effect of beer, red wine, whisky and their comparable pure ethanol solutions on gastric emptying in a controlled and randomized investigation.
Methods: On separate days, 10 healthy, fasted subjects received the following solutions, in random order, through a gastric tube: 500 mL beer, red wine, comparable pure ethanol solutions (4% and 10% v/v), glucose (5.5% and 11.4% w/v) and water, 125 mL whisky and 40% (v/v) ethanol (both followed by 125 mL water) and 250 mL water. Gastric emptying of the test solutions was assessed using ultrasonography of the antrum.
Results: As measured by ultrasonography of the antrum, half emptying times of the ethanol solutions (4%, 10% and 40% v/v) were significantly (P < 0.05) longer (22.6 +/- 4.8, 22.7 +/- 4.3 and 27.8 +/- 3.3 min, respectively, n=10) than those of water (14.6 +/- 1.9 min (500 mL) and 13.2 +/- 1.7 min (250 mL), respectively). The half emptying times of beer (39.3 +/- 4.3 min) and red wine (72.6 +/- 7.6 min) were significantly longer than those of the corresponding ethanol concentrations, whereas whisky was emptied at nearly the same rate (26.4 +/- 5.9 min) as 40% (v/v) ethanol. Emptying of glucose 5.5% and 11.4% (w/v) was significantly and dose dependently slower (29.7 +/- 4.5 and 64.8 +/- 8.9 min) than water.
Conclusions: 1) Pure ethanol in concentrations of 4%, 10% and 40% (v/v) inhibits gastric emptying. 2) The inhibitory effect of beer and red wine, but not of whisky, is stronger than that of their comparable ethanol concentrations. 3) Caloric content and non-alcoholic ingredients in alcoholic beverages produced by fermentation (beer and wine), but not in those produced by distillation (whisky), are most likely responsible for this effect.