Espresso Martinis Are Delicious—but What Happens to Your Body When You Mix Alcohol and Caffeine? A Doctor Explains

The more you know!

Cocktails combining alcohol and caffeine aren't a new idea by any stretch: Rum and Coke, Red Bull and vodka, Irish coffee, and many other mixed-drink combinations have been bar staples for years. But there's just something special about the espresso martini—it feels like a decadent treat. Since it's typically made with espresso, coffee liqueur, vodka, and often a hint of simple syrup, it has all the qualities of a delicious dessert, post-meal pick-me-up, and an elegant cocktail at the same time, which makes it all the more tantalizing. First concocted by London bartender Dick Bradsell in the '80s, espresso martinis have made a serious comeback recently. They're on just about every menu these days, and this velvety sip is so good it can make you feel like you're not drinking any alcohol at all (a gift and a curse).

But have you ever wondered what happens in your body when you drink caffeine and alcohol together? Is this drink (or other liquor-caffeine combos) safe to enjoy—or should we actually avoid mixing them altogether? To find out exactly how this type of cocktail affects your health, we tapped Seema Bonney, MD, functional medicine doctor and founder of the Anti-Aging and Longevity Center of Philadelphia, to break it all down.

What happens in your body when you mix alcohol with caffeine?

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Caffeine can make you feel less drunk than you actually are.

Let's start with the caffeine component of an espresso martini, which Dr. Bonney says you need to pay attention to. When you ingest caffeine, it "wards off drowsiness and suppresses adenosine, [a natural chemical in the body which] helps regulate wakefulness and sleepiness and builds up in your brain throughout the day," Dr. Bonney explains.

Alcohol, on the other hand, "causes adenosine to accumulate, making you feel drowsy," she continues. When both are mixed and ingested, caffeine can mask the depressant effects of alcohol. "This makes drinkers feel more alert and gives the feeling that they can handle more alcohol, creating increased impairment and more risk for harm," she says.

But this doesn't mean that caffeine sobers you up. If you've ever turned on your TV, you've probably seen characters in movies and shows suggest a strong cup of coffee for someone who's had too much to drink. "Caffeine has no effect on the metabolism of alcohol by the liver, and thus it does not reduce blood alcohol concentrations or reduce impairment," she says. (The only way to sober up is time.)

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It can be a double hit of dehydration.

Alcohol is a diuretic, meaning consuming it actively removes water from the body. That's one huge reason why you wake up feeling awful after a night of drinking: Your body is dehydrated. "Because caffeine is a mild diuretic, the combination may be even more dehydrating," Dr. Bonney says. To stave off dehydration, water is your best friend. "If you plan on having a few cocktails, it's best to be well hydrated throughout the day: Drink half your weight in ounces of water daily; consume a glass of water in between each cocktail; and [drink] another before you go to bed and as soon as you wake."

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Too much is unhealthy for your heart.

In addition to sending the alert to your body that you can handle more alcohol than usual, the mixture of caffeine and alcohol can be potentially dangerous for your heart. "It has already been established that excessive amounts of alcohol can negatively impact heart health, combining alcohol with caffeine could put you more at risk, especially if regularly consumed together," Dr. Bonney explains. "Caffeine and alcohol both stimulate atrial fibrillation, aka irregular heartbeat. Both can have a dire effect on the quality and quantity of sleep, which can lead to even more health issues," she says.

Bottom line?

Enjoy your cocktail—but always practice moderation. "An occasional, indulgent espresso martini [or other combo cocktail] is not likely to cause any harm, we just want to avoid creating a habit of mixing alcohol and caffeine," says Dr. Bonney.

If you're having trouble staying awake during a night out and want to try some sort of alcohol and caffeine drink, Dr. Bonney says to consider the amount of caffeine in the beverage. "The higher the caffeine content, the greater the stimulant effect and masking of alcohol effects," she says. Dr. Bonney points out that a standard cup of coffee has about 95 to 165 milligrams of caffeine in each cup, whereas an energy drink typically contains anywhere from 40 to 350 milligrams of caffeine and typically includes added sugars, which is an additional stimulant.

Of course, how your body handles the mix of caffeine and alcohol depends on a variety of factors, including personal health history, how often you drink them, and more, so there's no one-size-fits-all answer for everyone.

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