If the cold, dark days of winter make you crave alcohol, you are far from alone.
An international team of researchers bent over – or rather dumped – through much of the world's data to test a widely accepted assumption. They found that people living in colder places with less sunlight are not only more likely to drink but are also more likely to consume alcohol and are more likely to suffer from alcohol-related liver disease.
"Because you think that when you're cold, you're more at home, and alcohol can create some warmth inside your body," said Dr. Juan Gonzalez-Abraldes, a professor of medicine at the University of Alberta. authors of the study. authors of the research published online by the journal Hepatology.
"We thought people in colder climates would drink more, so we wanted to approach this from a scientific point of view by providing data, numbers and analyzes."
The researchers used data from the World Health Organization, the World Meteorological Organization and other public data sets to compare mean temperatures and hours of sunlight from different regions with statistics on alcohol consumption and alcoholic cirrhosis.
Data came from 193 countries, including Canada. US numbers were broken down by state and municipality, but Canada was considered as a whole and not divided by region or jurisdiction.
Dr. Ramon Bataller, a University of Pittsburgh researcher and lead author of the report, said the goal was to determine if there was indeed a verifiable relationship between the weather and the drunkenness.
"We were very surprised that this particular study has never been done in the past," Bataller said.
"In Russia they drink a lot, in Minnesota they drink a lot, everyone says," it's so cold, you need to drink "- but something that was assumed was never studied."
Data trends were clear, Bataller said.
"When we correlate, we find that the colder the countries, the darker, the heavier the alcohol consumption and the alcoholic cirrhosis," he said.
Controlling by Religion
Researchers acknowledge that there are many confounding factors, such as religion. Muslim-majority countries tend to consume less alcohol, whatever the weather, as well as some regions of the US where drinking is more strictly regulated, such as Utah.
The researchers said they controlled as many confounders as they could, but some could not be controlled, according to Bataller.
For example, alcohol consumption data is based on sales figures, and Bataller said that people in developing countries may be more likely to drink home-made drinks.
"The hottest places, you do not record as much as they drink," Bataller said.
Timothy Stockwell, a professor at the University of Victoria and director of the Canadian Institute for Substance Use Research, has worked on alcohol research for decades from Australia to northern Canada. He said that this new research is valuable – but mostly as a starting point.
"It was well done, but I think there are a lot of questions. That raises more questions than answers," he said.
One big question, he said, is how far away factors are. In other words, people from small northern communities drink because it's cold and dark, or because there's little else to do for fun?
"In northern Australia, in remote rural areas where it is unbelievably hot, you have the same phenomenon of people drinking more than in built-up areas," he said.
"There is more focus on getting together and drinking a lot in remote rural areas, and this may have nothing to do with temperature."
He also points out that the research did not break the data by season – and there is evidence that beverage spikes during hot flashes.
"So it's not as simple as it's colder, the more you drink – it's also the case that the warmer, the more you drink."
Still, Stockwell said that even if the research does not prove any causal connection between climate and drink, it is still valuable because it highlights a clear correlation.
"I think this kind of research is fantastic, and that starts conversations. And I think more people should look for it and try to struggle to understand it better," he said.
"It's something real, but we do not understand exactly why it's the case."
Bataller agrees that his study should be a starting point for researchers and policy makers interested in alcohol as a public health problem.
"It's one of the pieces of the puzzle, how to avoid heavy alcohol [consumption]and the consequences, "he said.