A recent BMJ editorial1 discussed the World Cancer Research Fund (WCRF) report on cancer2 and commented on the report's recommendation that men should drink no more than two units of alcohol a day and women no more than one unit a day. These recommendations are much lower than current government advice in Britain.2 This highlights a widespread confusion regarding units of alcohol and “standard” drinks—WCRF “drinks” contain 10-15 g of ethanol and British units contain 8 g.
Although a unit is often taken as one drink (half a pint of beer or one glass of wine), this is not the case. One pint of beer (4.2%) contains 2.4 units and a 175 ml glass of wine (12%) contains 2.1 units. The Department of Health leaflet, How Much is Too Much?, promises information on the number of units in alcoholic drinks. It advises using smaller glasses, stating that a 125 ml glass of wine contains one unit.3 This would be true if the alcohol content was 8%, but at a more typical 12% it contains 1.5 units.
Furthermore, the standard drink varies across the world. The WCRF report is an international publication, which may explain the wide range of ethanol contents per drink (10-15 g) in the recommendation.
In 1991, Miller et al issued “a plea for consistency” regarding alcohol content.4 Given the ambiguity present in the WCRF report, and the confusion evident even in a BMJ editorial, it is surely time to heed that plea.
Competing interests: None declared.
References
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- 3.Department of Health. How much is too much? 2006. London: DoH. www.dh.gov.uk/en/Publicationsandstatistics/Publications/PublicationsPolicyAndGuidance/DH_4139672.
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