As the size of our wine glasses increases, so too does our alcohol intake, suggests new research.
A new study published in the Christmas edition of The BMJ looks at the changes in wine glass size over time and the evolution of our drinking habits.
Theresa Marteau, a professor of behavior and health at the University of Cambridge in the United Kingdom, led the research.
As Prof. Marteau and colleagues note in their study, alcohol consumption has increased dramatically in recent decades.
Wine drinking, in particular, increased by nearly four times from 1960 to 1980 and went on to almost double between 1980 and 2004.
Why is that? It is widely accepted that the increased affordability and availability of wine led to an increase in consumption, but the new research suggests that the size and design of wine glasses may also have contributed to this.
In much the same way that larger plates are believed to have led to greater food consumption, so might glass size have triggered a higher wine intake, the researchers hypothesize.
Wine glasses seven times larger today
Using online databases and interviewing antique glassware experts, Prof. Marteau and colleagues collected information on the size of 411 wine glasses between the years 1700 and 2017.
Some of the sources that were used for studying glass size were the Ashmolean Museum of Art and Archaeology at the University of Oxford, the Royal Household, the catalogs of manufacturer Dartington Crystal, and the website of the John Lewis department store.
The analysis revealed that the size of wine glasses has increased by sevenfold in the past 300 years. Specifically, the capacity of the glasses increased from around 66 milliliters in the year 1700 to around 449 milliliters in 2017.
"[Wine glass] capacity has increased most steeply over the past two decades, along with wine consumption," write the researchers.
Glass size policies may reduce drinking
Prof. Marteau and colleagues note that given the observational nature of the study, they cannot infer a causal link between the increase in wine glass capacity and that in wine consumption.
But they also add, "While this association may not be causal, some evidence of a link between wine glass size and drinking suggests that reducing the size of wine glasses in licensed premises and in our homes could reduce consumption."
To this end, they list some suggestions for new policies, such as, "Encouraging wine producers and retailers to make non-premium bottles of wine available in 50 cL [centiliter] and 37.5 cL sizes, with proportionate pricing."
This may "encourage drinkers to downsize their wine glasses so that one bottle fills more glasses," they add.
However, the study authors predict that the "palatability [of these suggestions] will be greater in the month of January than in December."