People monitoring their alcohol intake often rely on governmental guidelines to assess whether how much they're drinking is likely to have adverse health effects.
But researchers at the Stanford University School of Medicine have found that such guidelines for low-risk drinking vary widely among countries. Some, like the United States, assign different daily or weekly limits for men and women, while others, like Australia, don't differentiate by gender.
Furthermore, the amount of alcohol in each country's "standard drink" can range from 8 to 20 grams. Toss in the need to calculate -- on the fly -- how many grams each drink contains based on the volume, which could be listed in ounces, milliliters or even imperial pints, and the alcohol content of the type of beverage in question (is it indicated as a percentage? a proof? as "alcohol by volume"?) and you've got a major headache even before you've taken that first sip.
It's confusing, to say the least -- both for people trying to drink responsibly and for researchers wishing to study global patterns of alcohol use and addiction.
"There's a substantial chance for misunderstanding," said Keith Humphreys, PhD, a professor of psychiatry and behavioral sciences at Stanford. "A study of the health effects of low-risk drinking in France could be misinterpreted by researchers in the United States who may use a different definition of drinking levels. Inconsistent guidelines are also likely to increase skepticism among the public about their accuracy. It is not possible that every country is correct; maybe they are all wrong."
A paper describing the researchers' findings will be published online April 12 in Addiction. Humphreys is the senior author. The lead author is psychiatric medicine resident Agnes Kalinowski, MD, PhD.
Kalinowski and Humphreys surveyed the definitions of "standard drink" and low-risk drinking in each of 37 countries around the world. They found that, although the World Health Organization defines a standard drink as one containing 10 grams of alcohol, most countries have their own ideas. A standard drink in Austria, for example, contains 20 grams of alcohol, while those in Iceland and the United Kingdom contain 8 grams. The United States splits the difference, with a standard drink of 14 grams of alcohol, which is roughly the amount in a 12-ounce bottle of beer or a 5-ounce glass of wine.
Different definitions of low-risk drinking
Many countries also provide different definitions of low-risk drinking -- or the amount of alcohol that can be consumed per day or week without experiencing adverse health effects. Men and women in Australia are told they should drink no more than 20 grams each day; American women are allotted 42 grams per day but no more than 98 grams per week. In contrast, men in the United States are told they can safely drink 56 grams per day and up to 196 per week. The upper weekly limit for men in Poland is substantially higher, at 280 grams per week.
The variability seen by the researchers reflects the need for more study about responsible alcohol consumption and also the differences in cultural attitudes among countries, according to Humphreys.
"More and more countries are trying to give their citizens guidelines about how much alcohol is safe to drink, and for whom," said Humphreys. "At the very least, we should know whether it's true that women should drink less than men. But even this is unclear.
"We've also learned that what constitutes a 'standard drink' in each country is far from standard, despite the WHO's recommendation. But in many cases these guidelines are adopted as public health policy and even printed onto alcoholic beverages without knowing whether people read them, understand them or change their behavior as a result."
The research was supported by the U.S. Veterans Health Administration.
Stanford's Department of Psychiatry and Behavioral Sciences also supported the work.
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