[Diurnal differences in alcohol absorption]

Under standardized conditions five subjects were submitted twice to a dose of alcohol of 1.1 g/kg. This dose was administered once between 7:15 and 7:45 am. and at a different day between 7:15 and 7:45 pm. The blood alcohol concentration curves in the morning and the evening differed significantly in peak and time elapsed until this value was reached. During the morning the peak averaged 32% higher than in the evening. In the morning it was reached after about 60 min and during evening after 110 min. The elimination rate was about the same. These results show that alcohol is significantly faster absorbed into the blood in the morning than during the evening. This could be explained by accelerated transport of uptaken alcohol into the bowels.