Study: People drink more alcohol in colder climates

Global data sets show the patterns

Americans up North who hole up every winter with a hot toddy or two may not be surprised that their drinking tradition has something to do with the climate.

Researchers at the University of Pittsburgh have confirmed, by studying global data, that it’s true around the world: Climate and drinking patterns are inversely related, meaning the warmer and sunnier the climate, the less people drink alcohol.

Reported in the journal Hepatology online by Meritxell Ventura-Cots and Ramon Bataller, the study examined average temperatures and annual sunshine hours with liters of annual alcohol consumption per capita for 193 countries.

In hot climates, alcohol increases the danger of dehydration. But because alcohol increases blood flow to the skin, drinking can make a person feel pleasantly warm in cold climates.

So it wasn’t a surprise that the study found the percentage of binge drinking — heavy episodic drinking — and the total number of drinkers went up in places with lower temperatures and fewer hours of sunshine.

“Everybody assumed this, but nobody has demonstrated it,” Dr. Bataller said, adding that climate also correlated similarly with rates of cirrhosis of the liver and alcoholism. It’s not that people who live in colder climates are more susceptible, he said, it is just one factor in higher rates of drinking.

The World Health Organization reports that 3 million deaths occur each year as a result of alcohol overuse, which is also blamed as contributing to more than 200 diseases and injuries.

The study findings, which included maps that focused on the world, show inversely related drinking/climate patterns that are obvious in northern latitudes closest to the Arctic Circle, including Russia, parts of Europe and Canada and Alaska. The continent of Africa shows the most obvious pattern in the direction of a hot, sunny climate and less drinking.

The researchers used large public data sets, including from WHO and the World Meteorological Organization, to confirm an idea already generally accepted. The study was funded by the National Institute on Alcohol Abuse and Alcoholism and Mexican and Spanish organizations.

“Any factor that contributes to alcohol drinking is of interest to policymakers,” said Dr. Bataller, associate director of the Pittsburgh Liver Research Center at Pitt. The connection to fewer hours of sunlight, he said, “tells us to prevent alcohol abuse and alcoholism, resources should be focused more in cold places.”

The study made adjustments for various confounding factors, including religion, especially in countries where Islam is the predominant religion. There are many things, in groups of people and in individuals, that affect patterns of alcohol consumption and alcohol problems, according to WHO.

The Pitt study also did a detailed analysis in the United States — for all 50 states and 3,144 counties. The same correlations of climate and alcohol drinking were found, although only nine counties in Hawaii and Florida belonged to the tropical category used in the global analysis and only two counties in Alaska were in the polar category.

Alcohol consumption was measured as total alcohol intake per capita, percent of the population that drinks alcohol, and the incidence of binge drinking.

For people with a genetic predisposition to alcoholism or with family members who abuse alcohol, Dr. Bataller said, “maybe you should avoid living in a very cold place ... If you are predisposed to drinking, don’t go to Alaska; you’ll probably drink more.”

Ms. Ventura-Cots, a postdoctoral researcher at the Liver Research Center, said global data included some estimates of drinking in countries where it is forbidden — that was not included in the study. She said confounding factors that were adjusted in the final numbers included obesity, smoking prevalence, diabetes and inequality — a factor that in the U.S. has been found to lead to more alcohol drinking.

The research was needed, Dr. Bataller said.

“Alcohol abuse is one of the main preventable factors in reducing mortality in the world.”