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Beware of Caffeine: It Can Raise Your Chances of a Drunk Driving Arrest

In recent months, there have been a number of reports warning the public not to consume caffeinated energy drinks with alcohol, like Red Bull with vodka. For example, this study reported on a CNN blog June 8 showed that student athletes were more likely to binge-drink if they mixed the alcohol with caffeine. In fact, the Scottish arm of the UK’s Labour Party is considering a ban on alcoholic drinks with a certain percentage of caffeine. Studies have indicated that people consuming caffeine with alcohol feel less drunk even though they actually are often more drunk than people who have been drinking alcohol without caffeine. This is because as alcohol is metabolized, it reduces glucose available to the brain, which makes you feel tired. But when caffeine is added to the mix, it masks the tiredness with its stimulant properties, so people don’t recognize how drunk they are.

However, as a Massachusetts intoxicated driving defense lawyer, I was fascinated to read that studies have also shown that caffeine can have a “synergistic” effect with alcohol. British researchers reported in “Interactions of Alcohol and Caffeine on Human Reaction Time,” Aviation, Space and Environmental Medicine 528 (June 1983), that “Caffeine has a synergistic interaction with alcohol…(It) has the effect of potentiating the detrimental effects already induced by alcohol….Motor skills which involve delicate muscular coordination and accurate timing have been found to be adversely affected by caffeine.” That means caffeine can increase the symptoms of alcohol intoxication — not counteract them, mask them, or help you to “sober up.” In essence, it makes people seem more drunk than they really are.

This is important for a Massachusetts OUI defense attorney like me to know about, because it could provide an avenue of defense for clients charged with intoxicated driving. For someone pulled over by the police for drunk driving, this means that their performance on a field sobriety test could perform worse than they would have without the caffeine. The caffeine would make them shakier and less able to perform the field sobriety tests than the alcohol alone would have left them. Field sobriety tests are supposed to provide evidence of whether a person is intoxicated, by demonstrating whether they can perform tasks such as “walk-and-turn”, “finger-to-nose” and “one-leg-stand.” These tests are not always possible for people who are haven’t even consumed any alcohol to perform perfectly, so the tests’ accuracy is less than ideal. For example, the test results can be affected by a person’s age, weight, athletic ability, emotional state, fatigue, and lack of familiarity with the tests. They can also be affected by conditions including passing traffic and by the police officer’s communication skills. With the addition of caffeine, the test results could make the person appear to be drunker than he or she really was, and the person would be more likely to get arrested.


If you have been charged with OUI in Boston or eastern Massachusetts, please contact Massachusetts intoxicated driving defense attorney Stephen Neyman as soon as possible to help you get the best possible outcome. You can set up a free consultation at (617) 263-6800 or contact us online.