Low-alcohol beers: contribution to blood-ethanol concentration and its elevation above the UK legal limit after 'topping-up'.

AIMS:The aim of this study was to establish the contribution of low-alcohol beers to blood-ethanol concentration (BEC) and to test if 'topping-up' with these beverages can increase BEC above the 80 mg/dl UK legal limit. METHODS:Healthy male and female volunteers received a dose of ethanol designed to give a BEC of just below 80 mg/dl, and then received one pint (600 ml) of a 1% v/v alcohol beer in the fasting state or after lunch, or of a zero-alcohol or a 0.5% v/v alcohol beer after fasting. BEC was determined enzymatically and data were subjected to ANOVA. RESULTS:Topping-up with a pint of a 1% v/v alcohol beer increased BEC >80 mg/dl in fasting subjects, contributing an extra 12-17 mg/dl, which lasted longer in males (80 min) than in females (20 min). A 0.5% v/v alcohol beer increased BEC above 80 mg/dl only in males, which lasted for 60 min. After food intake, the 1% v/v alcohol beer increased BEC above 80 mg/dl transiently only in males. CONCLUSIONS:Low-alcohol beers make a significant contribution to blood-ethanol concentration and can increase it above the UK legal limit. Their use as a 'top-up' should be discouraged. Low-alcohol beers have a place as a substitute for normal-strength beverages as a strategy for decreasing alcohol consumption in general and in countries where low legal alcohol limits are in force or being contemplated.