Underestimating the alcohol content of a glass of wine – lower actual risk for high consumption
In recent years, the intake of alcoholic beverages has probably been underestimated in population studies in the UK due to bigger glasses and an increase in the wines’ strength. This underestimation affects the estimates of mortality risk.
A scientific report from the Department of Epidemiology and Public Health, University College London (UK) suggests that wine consumption has been misclassified due to the increases in glass sizes and wine strength over the last 25 years. The scientists explored whether this misclassification affected the association between the average alcohol intake and risk of mortality from all causes, cardiovascular disease and cancer in the 7010 men and women in the Whitehall II cohort of British civil servants who were followed up from 1997-1999 until mid-2015. A conversion factor of 8 g of alcohol per wine glass (1 unit) was compared with a conversion of 16 g per wine glass (2 units). When a glass of wine was considered to contain 16 g of alcohol as opposed to 8 g of alcohol, there was a substantial shift in the proportion of drinkers who were classified as moderate into the heavier categories. This study was the first to demonstrate that, in a population-based cohort study, such a misclassification can translate into an overestimation of the health risks associated with very heavy drinking compared to moderate consumption.
Britton A, O’Neill D, Bell S. Underestimating the Alcohol Content of a Glass of Wine: The Implications for Estimates of Mortality Risk. Alcohol Alcohol. 2016 Jun 3. [Epub ahead of print]
For more information about this article, read the scientific abstract here.