What Is Moderate Drinking?

Alcohol Research & Health, Wntr, 1999 by Mary C. Dufour

In recent years, the alcoholic beverage market has become even more diversified. For example, beverages such as "light" beer, "light" wines, and wine or spirit coolers, which have slightly lower alcohol contents than the corresponding regular beverages, have been introduced. Conversely, both the relatively new "ice" beers and "dry" beers have higher alcohol contents than do either regular or "light" beers (Williams et al. 1997). Other beverages with higher alcohol content than the corresponding "regular" beverages, such as premium brand liquors, fortified wines, malt liquors, and locally produced beers and ales (i.e., microbrews), also have become more popular. Finally, large 40 ounce (oz) beer bottles have been introduced. Thus, a person drinking such a bottle may still report having had just one drink, although the amount consumed is approximately equivalent to the beer in three regular 12 oz bottles. These examples illustrate the difficulties encountered in determining and comparing actual alcohol consumption and the contents of various types of beverages for establishing a standard definition of a drink.

The alcohol contents of beer, wine, and spirits vary substantially within each category.(1) To calculate and compare the alcohol contents of various beverages, however, scientists must select one conversion factor (or average alcohol content) for each category to reflect the alcohol contents of beer, wine, and spirits. One set of conversion factors that frequently is used in the United States defines average alcohol contents as follows (Doernberg and Stinson 1985):

* Beer - 4.5 percent alcohol

* Wine - 12.9 percent alcohol

* Spirits - 41.1 percent alcohol.

The variability in the definition of a standard drink arises not only from differences among studies in the type of alcohol and the conversion factors used but also from the way in which the results are reported. For example, researchers can represent alcohol consumption as grams (g), milliliters (mL), or fluid ounces (fl oz) (American or British) of alcohol; beverage equivalents (e.g., "beer equivalents" or "whiskey equivalents"); or number of drinks, which can be variously defined. These different reporting methods can confuse the readers of various studies and complicate the comparison of study results. For example, people who are familiar only with the U.S. system of weights and measures will not know how much alcohol is present in a drink that contains 12 g alcohol. (For a conversion of milliliters of alcohol into grams and fluid ounces, see the table below.)

With all the confounding influences, not surprisingly, the sizes of standard drinks vary substantially among different countries. For example, a standard drink in Great Britain (i.e., a "unit") is equivalent to 8 g alcohol, whereas a [TABULAR DATA OMITTED] standard drink in Japan (i.e., a "go") is equivalent to 19.75 g alcohol (Turner 1990). In the United States, the U.S. Department of Health and Human Services (DHHS) and the U.S. Department of Agriculture (USDA) have developed a commonly used definition of a standard drink that has been published in Nutrition and Your Health: Dietary Guidelines for Americans (DHHS and USDA 1995). According to that definition, a standard drink contains approximately 0.5 fl oz (or approximately 12 g) alcohol and corresponds to the following beverage amounts: