This holiday season, mixing diet soda (or any diet drink) with alcohol will make you seem drunker, at least to a Breathalyzer.

For the past few years, a group of psychologists have measured the effects of using artificially sweetened drinks — in place of sugary ones — when throwing back a few.



The findings from the most recent study, due to be published in the December issue of the journal Drug and Alcohol Dependence but released last month, show that drinking vodka mixed with diet soda boosted breath alcohol concentrations 20 percent higher than did the same amount of vodka mixed with sugary sodas.

It appears the reason for the elevated alcohol concentration is the absence of the sugar, which slows the absorption of alcohol, as researcher Cecile Marczinski told NPR in 2013. Take that away, and the alcohol hits the bloodstream faster.