Alcohol is a drug that impairs judgment, reaction time, movement, coordination and vision. Though the blood alcohol content legal limit for someone driving a car used to be 0.10 in some states, it is now 0.08 in all states. In Michigan, it will change to 0.10 from 0.08 on October 1, 2013. Even though 0.08 is considered the “legal limit” in most states, courts can still find someone legally drunk with a BAC below 0.08 if the driver is under 21 or shows signs of impairment [ref].
BAC is a measurement of how much alcohol has been absorbed into someone’s bloodstream and is greatly affected by the rate of alcohol consumption. Generally, the faster someone drinks, the more inebriated (drunk) he or she becomes. The type and amount of alcohol does make a difference. One drink equals 12 ounces of beer, five ounces of wine or a 1.5 ounce of 80-proof liquor. (Proof is a measurement of how much alcohol a liquor contains -- 80 proof means 40 percent alcohol, 70 proof equals 35 percent alcohol, etc.) All of these measurements contain 0.54 ounces of ethyl alcohol, the substance that makes you intoxicated.
As alcohol accumulates faster than the body can process it, a person becomes drunk. On average, a person metabolizes, or processes, one drink per hour. Women, who generally have less muscle mass than men, are more susceptible to the effects of alcohol because muscle slows down the absorption process. Women also produce less of the enzyme dehydrogenase, which helps in breaking down alcohol.
Height, weight and body fat also affect blood alcohol content. Eating high protein foods, such as nuts, meat, pizza and cheese, can help to slow down the absorption of alcohol.
The mistake that people often make is thinking that certain liquors or drinks affect someone differently or that mixing alcohols increases drunkenness. As seen above, different types of drinks can be equally potent. What matters is the alcohol content. Drinking four 12-ounce beers has the same affect as taking four 1.5-ounce shots of 80-proof vodka in the same time period. Some types of beer and wine do contain more alcohol than others, but this is a general guide.
Many people believe that drinking water or coffee, exercising, napping or taking a cold shower will make someone more sober, but only time can help someone sober up. What matters is the body having time to metabolize the alcohol -- not how much someone thinks he or she is sober.