Activation of ethanol metabolism in humans by fructose: importance of experimental design

Fed human male subjects 18 to 30 years of age received 0.85 g/kg of ethanol p.o. as vodka followed by a second drink (0.3-0.4 g/kg) given 3 to 4 hr later. Blood ethanol levels reached approximately 100 mg% after both doses. Breath samples were taken every 20 to 30 min, and the rate of ethanol elimination was determined. Subjects returned 1 to 2 weeks later and the study was repeated with fructose (1.0 g/kg). When ethanol and fructose were given simultaneously, the peak blood ethanol values reached were reduced significantly. This resulted in calculated increases in the apparent volume of distribution of ethanol; however, the slope (beta) of the ethanol elimination curve was not increased. Thus, under these conditions, fructose appeared to have minimal effects on rates of ethanol elimination (ca. 10%). In another experimental design, subjects received 1 g/kg of fructose 1 hr after ethanol. Under these conditions, fructose did not affect the peak blood ethanol concentration or the apparent volume of distribution; however, the slopes of the ethanol elimination curves (beta) were increased significantly by fructose. Further, the time estimated to eliminate the ethanol completely was reduced by 90 min with fructose. Under these conditions, the stimulation of ethanol elimination by fructose was 20 to 30%. This increase in the rate of ethanol elimination was observed in every subject studied. Similar results were obtained with rats. To understand why blood ethanol values were lower when ethanol and fructose were given simultaneously, female Sprague-Dawley rats were given ethanol alone (1.5 g/kg) or ethanol and fructose (1 g/kg) simultaneously.(ABSTRACT TRUNCATED AT 250 WORDS)