Impact of bottle size on in-home consumption of wine: a randomized controlled cross-over trial. Codling S, Mantzari E, Sexton O et al.  Addiction. 2020;115:2280-2292.
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This study took 186 UK households that typically drank 2-8 75cl bottles of wine per week. They were randomised to two different groups and both bought a set volume of wine, only in one group they got it in 75cl bottles and in the other 50cl bottles. This lasted for two weeks and then the crossover happened - for another two weeks they had their fixed volume of alcohol in smaller 50cl bottles or larger 75cl bottles.

The main outcome was the amount of wine consumed. They found that more wine was consumed by the households when it was suppled in 75cl bottles — there was a 4.5% reduction or 191.1ml on average. They also measured the rate of consumption and it was 5.8% faster from 75cl bottles. 

Commentary:

The numbers are quite small but the study only went on for 14 days in each period — we’d need a much longer study to see if the results held over longer periods or whether people started to compensate in some way. We also need data to ensure 50cl bottles didn’t, paradoxically, increase consumption via other mechanisms.

This nice little study is a good reminder that sometimes, as clinicians or other workers, it doesn’t make a lot of difference what we do in comparison with the public health population level interventions. Here’s one to add to the list alongside minimum unit pricing that we could, as a community, advocate for and support. As drinking wine is so often a social activity, there is a tendency to polish off the bottle. This experimental evidence suggests that switching to 50cl bottles from the current standard 75cl could make quite a difference. And these small differences really add up across the whole country. 

Article taken from our latest Clinical Update, edited by Euan Lawson. To read the full Clinical Update please become an SMMGP Premium Member.