Study Says Heavy Drinkers Can't Actually Hold Their Alcohol

Think you can hold your alcohol? You might want to think again, because a new study found that heavy and problem drinkers exhibit the same level of impairment as light drinkers after knocking back a few.

The study, which was conducted by researchers at the University of Chicago, examined three groups of drinkers—light drinkers, who consume 2.5 drinks per week, heavy social drinkers who imbibe around 20 drinks per week, and people with alcohol use disorder who average 38.7 drinks per week. Moderate drinkers were not included in the study so a clearer distinction would be made, and also because there could be some overlap between the extremes.

The three groups were each tested twice, once using alcohol, and another time with a placebo designed to mimic the taste of alcohol. Participants who received alcohol were given a quantity measured by body weight to ensure that the effects were even across various body types. Women were also given 85 percent of the dose given to men, since they metabolize alcohol differently and can become intoxicated faster and more easily.

To test the effects, participants were given two cognitive tasks before drinking and at each half-hour interval—a fine motor task that scored on how quickly participants could put pegs into holes, and a pencil-and-paper cognitive task. Additionally, the groups were asked how impaired they felt on a scale of “not at all” to “extremely” at 30 and 180 minute intervals.

Initially, the findings seemed to support the theory of tolerance, as both groups of heavier drinkers did not report feeling impaired within 30 minutes, and likewise had no issue with the written cognitive test. However, all three groups struggled equally when it came to putting pegs into holes at the 30 minute mark.

The researchers also gave the 60 participants who had alcohol use disorder a second dose containing 190-proof alcohol, about the equivalent of seven to eight standard drinks, to more closely replicate their usual drinking habits. The study concluded that those participants demonstrated 50 percent more mental and motor impairment than they had after taking the first dose, and it took three hours to get back to their baseline level of task performance.

“It seems to be a popular perception that experienced drinkers can handle their liquor,” Nathan Didier, research analyst at the Clinical Addictions Research Laboratory at the University of Chicago and coauthor of the study, told CNN. “Like two cowboys in a bar in a drinking competition, and they have some macho strength to take in so much alcohol and handle it.”

“What this study does is put a spotlight on the limitations of tolerance,” Didier added. “Even if you have a lot of experience drinking, that doesn’t mean that you’re not impaired—that’s an important takeaway.”