Alcohol Consumption

Harms and Benefits

The potentially harmful aspects of alcohol are well known, representing the majority of medical and societal campaigns directed at alcohol. More specifically, we know that overuse of alcohol, both acute and chronic, can cause harm. Acutely, alcohol consumption impairs reaction time and critical thinking abilities at blood alcohol levels of 0.03 mg/dl and higher. As a result, the person is at higher risk for motor vehicle crashes; in the United States, 40 percent of traffic fatalities are alcohol related. Those who drink excessive amounts of alcohol also suffer adverse consequences related to poor decision making and disinhibition, both of which are effects of alcohol. In addition, severe intoxication with alcohol can lead to blood alcohol levels high enough (e.g., 40–50 mg/dl) to cause coma, stupor, or death. Chronically, alcohol overconsumption can cause a wide range of consequences, including cognitive impairment, peripheral neuropathy, myopathy, and liver dysfunction.

However, there is increasing evidence that alcohol, when consumed in moderation, is both relatively benign and may have potential health benefits. Regarding the former position, the two sources of the medical evidence on alcohol, the study of the acute physiological effects of consumption and observational studies [Page 55]comparing abstainers with alcohol users, have made it difficult to extrapolate whether there are negative consequences for healthy users of moderate amounts of alcohol. However, we do know that alcohol is not benign in certain populations—for example, in pregnant women, those with family histories of alcoholism, and persons with hepatic/pancreatic disease, there is no harmless dose of alcohol.

As for whether alcohol consumption can be beneficial, the evidence suggests that for healthy persons without conditions contraindicating alcohol, 0.5 to 1 portion of alcohol per day (1 portion = one glass of wine, one can of beer) may have health benefits. A large study of nurses showed that those who consumed moderate amounts of alcohol had decreased mortality rates compared to those abstaining from alcohol. This finding is consistent with prospective studies from around the world, which have shown that relative risk of death for moderate drinkers, compared to abstainers, is 0.6 to 0.9. Ecological studies conclude the same, the most well known of which is the “French paradox” (the low rates of heart disease in France despite a high-fat diet, theorized to be attributable to high red wine consumption). It appears that the mechanism for this effect is the beneficial effect of alcohol on coronary heart disease; thus, those individuals at highest risk for heart disease appear to benefit the most.

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