Endogenous ethanol 'auto-brewery syndrome' as a drunk-driving defence challenge

The concentration of ethanol in blood, breath or urine constitutes importan t evidence for prosecuting drunk drivers. For various reasons, the reliabil ity of the results of forensic alcohol analysis are often challenged by the defence. One such argument for acquittal concerns the notion that alcohol could be produced naturally in the body, hence the term 'auto-brewery' synd rome. Although yeasts such as Candida albicans readily produce ethanol in-v itro, whether this happens to any measurable extent in healthy ambulatory s ubjects is an open question. Over the years, many determinations of endogen ous ethanol have been made, and in a few rare instances (Japanese subjects with very serious yeast infections) an abnormally high ethanol concentratio n (>80 mg/dl) has been reported. In these atypical individuals, endogenous ethanol appeared to have been produced after they had eaten carbohydrate-ri ch foods. A particular genetic polymorphism resulting in reduced activity o f enzymes involved in hepatic metabolism of ethanol and a negligible first- pass metabolism might explain ethnic differences in rates of endogenous eth anol production and clearance. Other reports of finding abnormally high con centrations of ethanol in body fluids from ostensibly healthy subjects suff er from deficiencies in study design and lack suitable control experiments or used non-specific analytical methods. With reliable gas chromatographic methods of analysis, the concentrations of endogenous ethanol in peripheral venous blood of healthy individuals, as well as those suffering from vario us metabolic disorders (diabetes, hepatitis, cirrhosis) ranged from 0-0.88 mg/dl. These concentrations are far too low to have any forensic or medical significance. The notion that a motorist's state of intoxication was cause d by endogenously produced ethanol lacks merit.