BEAR VALLEY, CALIF. — Seventy million Americans, according to latest estimates, are habitual users of alcoholic beverages. Almost all of them would describe themselves as "social drinkers."
A cross-tabulation of government surveys a few years ago by alcohol researcher Robin Room produced a definition of a heavy drinker as "someone who drinks twice as much as I do." While the social, psychological and biomedical consequences of heavy drinking are well known, most social drinkers derive great comfort and reassurance from the heralded reputation of moderate drinking as a beneficent adjunct to life that not only eases stress but contributes to good health and even longevity.
The news report a few weeks back of a possible chemical connection between alcohol and cancer had to give pause to every drinker who read or heard it. The report was based on a finding by Heinz Fraenkel-Conrat and Bea Singer, a husband-and-wife team of molecular biologists at UC Berkeley. Writing in the Proceedings of the National Academy of Sciences, the scientists declared that alcohol and acetaldehyde--to which alcohol converts in mammalian cells--combine to change DNA in a manner similar to changes produced by other cancer-causing chemicals.
"These reactions could play a role in the recently documented association between moderate use and increased incidence of breast cancer," the two scientists explained in a carefully worded press release. And from their vacation home in England, Singer added, with equal caution, "If indeed there is other evidence indicating that alcohol is a carcinogen, this could be a mechanism."
Although a statistical corollary between drinking and cancer has long existed--the more you drink, the greater your risk of developing cancer--no one until this point had been able to say precisely what role alcohol played. Many authorities speculated that alcohol bathes the body cells to such a degree that they become vulnerable to known carcinogens found in tobacco and even in the alcoholic beverage. Asbestos fibers, for example, have been found in beer, wine, sherry and vermouth. Until now, there had always been disagreement as to whether alcohol itself was a carcinogen; should the work of Fraenkel-Conrat and Singer be validated by further studies, that question will be answered.
The full significance of their research, however, can only be appreciated in context. It is one more in a series of relatively recent findings that appear to put the knock on alcohol consumption at levels few drinkers had ever considered dangerous.
Over the last 15 years, a number of researchers in the United States and abroad have developed the proposition that what passes for social drinking today in many parts of the world is so fraught with biomedical hazards it could be exposing millions of self-described "social drinkers" to serious health hazards, among them: liver problems, including cirrhosis; hypertension; cancer of the digestive tract; severe side-effects for those who simultaneously ingest alcohol and other mood-altering agents, or prescription and over-the-counter drugs; fetal damage even before confirmation of a pregnancy, and the impairment of sober intellectual capacities.
At what level of consumption might such damage occur? Although there is no universal agreement among those alcohol researchers responsible for the above findings, the consensus would appear to be that risks begin to rise after the consumption of the equivalent of 28 grams of absolute alcohol, or ethanol, a day--the approximate amount found in two 1.5-ounce martinis made with 80-proof gin, two five-ounce glasses of 12% wine or two 16-ounce cans of 4.5% beer.
The alcoholic-beverage industry disputes all such calculations about what constitutes a safe-drinking threshold, as well as most of the research on which they are based. It argues that the association between alcohol and diseases has never been conclusively established, and it contends that physical and genetic factors and even cultural perceptions about what constitutes "heavy" drinking make the answer different for each individual. The industry maintains that most Americans are not only moderate drinkers--per capita consumption in the United States being half that of Portugal and France, and well below that of Italy, West Germany and even Switzerland--but have tended in recent years to "lighten up," increasingly favoring beer and wine over spirits.