New American research has found evidence to support the long-term belief that those living in parts of the world where the days are shorter and colder drink more alcohol, potentially putting people at higher risk of liver disease.
Performed by researchers from the University of Pittsburgh Division of Gastroenterology, the new study investigated to investigate whether living in colder, darker climate allows people to consume more alcohol and the effect it may have on the risk of alcohol choir.
The researchers gathered information about 193 sovereign countries as well as 50 states and 3,144 counties in the United States using data from the World Health Organization, the World Meteorological Organization and the Institute for Health Statistics and Evaluation.
They then looked at the relationships between climate factors such as average temperature and sunlight hours, alcohol consumption (measured as total alcohol intake per capita), the percentage of the population who drink alcohol and how much binge-drinking.
The results, published online in the journal Hepatology, showed that when the temperature and the number of daylight hours fell, alcohol consumption increased.
The researchers also found evidence that colder, darker days also contribute to binge drinking and a higher alcohol-related disease, one of the main causes of death in those with long-term excessive alcohol consumption. The same results were found both when comparing countries around the world and when comparing counties in the United States.
"It's something everyone has assumed for decades, but no-one has scientifically shown it. Why do people in Russia drink so much? Why in Wisconsin? All assume it's cold," says senior writer Ramon Bataller, MD, Ph. D. . "But we could not find a single paper climatic climate for alcohol intake or alcohol cirrhosis. This is the first study that systematically shows that in the world and in America, in colder areas and in less-sunny areas you have more drinking and more alcoholic cirrhosis."
The team noted that they also took into account other factors that could affect how much a population drinks, for example, most Arab populations living in hot desert areas with a large number of sunlight hours would refrain from alcohol.
The researchers also checked for health factors that can exacerbate the effects of alcohol on the liver, such as viral hepatitis, obesity and smoking.
"It is important to highlight the many confounding factors," said lead author Meritxell Ventura-Cots, Ph.D. "We tried to check for as many as we could. For example, we tried to check for religion and how it affects alcohol habits."
They explained that in colder climates they can drink because alcohol is a vasodilator, which means that it increases the flow of hot blood to the skin, which is full of temperature sensors, and it can also increase the heat capacity. Drinking is also linked to depression, which tends to be worse during the winter months and when there is less solar radiation.