Because nothing says "Let's have a few drinks" like a dreary afternoon.
The new study analyzed data from 193 countries, finding that colder, darker climates are correlated with higher alcohol consumption and liver diseases. Senior author Ramon Bataller, associate director of the Pittsburgh Liver Research Centre, said:
"This is the first study that systematically demonstrates that worldwide and in America, in colder areas and areas with less sun, you have more drinking and more alcoholic cirrhosis."
This seems to make a lot of sense if you think about it. At a physical level, alcohol is a vasodilator -- it dilates your blood vessels, which increases the flow of warm blood to the skin. This means that consuming alcohol will make you feel warmer (although technically, your body is losing heat as it flows towards your skin, where it is easily lost), which could explain why people are more inclined to drink during cold spells. On a social level, people are also more likely to stay indoors when it's cold and dark outside, which can also lead to drinking -- particularly around Christmas and New Year's Eve.
There's also a connection between alcohol and depression, as well as a link between depression and a lack of sunlight -- putting two and two together, it seems plausible that alcohol and darkness go hand in hand.
However, not everyone is convinced, and despite this solid study, the evidence seems a bit contradictory with previous studies. Prof. Jurgen Rehm from the Centre for Addiction and Mental Health says that according to his work, there's no link between temperature, light, and alcohol consumption. Instead, he says, countries such as Ireland, the UK, Germany and Poland have the highest alcohol consumption, whereas northern (Norway, Sweden, Finland) and southern countries (Malta, Greece, Italy) have the lowest reported consumption. He also added that this pattern of alcohol consumption is not restricted to Europe -- anywhere you look, globally, the coldest and the hottest climates have the lowest alcohol consumption rates, which suggests that some other factor is at play.
However, Rehm also emphasizes the need to adopt healthy policies that reduce alcohol consumption. Earlier this year, Scotland implemented legislation that mandates minimum alcohol pricing -- a move which was widely praised by health organizations and scientists.
Despite what some producers would have you believe, and what a few isolated studies have found, alcohol is, almost always, quite bad for you. Even moderate alcohol consumption is associated with a swarm of health risks.