What Is Moderate Drinking?

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

* 12 fl oz regular beer

* 5 fl oz wine

* 1.5 fl oz 80-proof distilled spirits.

In the scientific literature, the wide range of assumptions about what a standard drink is can produce highly divergent estimates of total alcohol consumption among respondents who report consuming the same number of drinks. In a review of 125 international epidemiologic studies that related various health consequences to different levels of alcohol consumption, Turner (1990) presented a striking example of the impact of methodological differences in converting the number of drinks of various alcoholic beverages to grams of alcohol. Turner based the comparison on fictional respondents who reported drinking one standard drink (as defined in each study) each of beer, wine, and spirits for a total alcohol consumption of three drinks per day. Using the different methodologies and assumptions regarding alcohol contents employed in four highly respected studies, Turner found that the total alcohol amounts corresponding to three drinks per day ranged from 24 g to 48 g. Consequently, when reading an article that relates a certain number of drinks per day to a specific health benefit or risk, one must pay careful attention to how a drink is defined in that study. The wide methodological diversity helps to explain, at least in part, the seemingly contradictory study findings regarding the consequences of certain drinking levels. Miller and colleagues (1991) have extended Turner's analyses by providing simple calculation rules for converting alcohol- consumption data among four standard drinking units currently used by researchers. The authors urge the adoption of a common method for reporting alcohol consumption.

ASSESSING ALCOHOL CONSUMPTION

In addition to the problems associated with defining a drink, disputes over how alcohol consumption can best be assessed in population studies have hampered attempts to define moderate drinking. Some of those disputes stem from the fact that alcohol epidemiology incorporates characteristics off our major epidemiologic perspectives: (1) psychosocial epidemiology, (2) psychiatric epidemiology, (3) chronic disease epidemiology, and (4) epidemiologic sociology (Grant 1994). (See sidebar below for brief definitions of and differences among the four perspectives.)

Research conducted using each perspective seeks slightly different information from study participants. Because different research traditions have different focuses, each tradition emphasizes different research questions, which may be hard to compare across studies. On the one hand, this diversity can be advantageous in that the four disciplines complement each other in revealing drinking patterns and problems. On the other hand, the variability also can be a handicap, because the information collected about alcohol consumption often is not comparable across studies. For example, one survey may ask questions in a way that permits a diagnosis of alcohol dependence. Another study, however, may ask questions about alcohol consumption and alcohol problems without including specific diagnostic criteria, and thus a diagnosis cannot be made.