Health Q&A: Wine and the Legal Limit

Posted: February 14, 2007

Q: How much wine at dinner will put me over the legal limit (0.80 in most states)?

A: R. Curtis Ellison, M.D., a professor of medicine and public health at Boston University School of Medicine and director of the school's Institute on Lifestyle and Health, answers:

Most studies of blood-alcohol concentration (BAC) have involved the rapid consumption of an alcoholic beverage on an empty stomach. In one oft-quoted study (involving eight fasting males who were light drinkers), the peak BAC occurred at 30 to 60 minutes, reaching 0.19 after one drink, 0.46 after two drinks and 0.70 after three drinks, with all drinks consumed quickly. (Women would be expected to have about a 20 percent higher BAC after the same amount of alcohol.) If these same amounts were sipped slowly and with food, the BAC would be expected to be about one-half as high.

For the average male, sipping two to three 5-ounce glasses of table wine (with 12 percent alcohol) over dinner would be expected to result in a BAC of less than 0.5 (the level at which studies suggest some deterioration in the functioning of motor skills begins to occur). Women would reach the same level after slightly less wine. On average, it takes just over five hours for three drinks to be fully metabolized and for the BAC to return to 0.

Remember that people's responses to drinking alcohol vary dramatically (the response is affected by age, body size, gender, usual alcohol consumption, overall health, medications being taken, levels of certain enzymes and a number of genes), so set your limits according to your own responses after having one or more glasses of wine.

This item was excerpted from Dr. Ellison's article "Wine and a Healthy Lifestyle," originally printed in the Oct. 15, 2004 issue of Wine Spectator magazine.

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