The Real Reason You Can’t Get Enough of Coffee and Beer


Your genes may play a role in why you keep reaching for that second cup or glass.

  • Coffee and beer are some of our favorite beverages, but a new study found that our preference for them may be based on gene variants related to how they make us feel, not to how we perceive them to taste.
  • For example, people who metabolize coffee more quickly may be more likely to drink more of it, in order to keep up the stimulating effects of it.

If you’re like many runners, coffee fuels your run—and beer is often waiting for you when you return home. But ever wonder what’s driving your preference for those all-important beverages?

Turns out, it might not have anything to do the taste: It may come down to simply liking how they make you feel.

This might all boil down to genetics, but not to the genes affecting how you perceive taste, a recent study in Human Molecular Genetics found. Instead, the researchers found a link between genetics and the beverages’ psychoactive properties, or the way the drinks make you feel.

In the study, beverages were grouped into bitter-tasting (beer, coffee, tea, grapefruit juice, liquor and red wine) and sweet-tasting (nongrapefruit juices, sugar-sweetened beverages, and artificially sweetened beverages). Researchers had over 330,000 people in the U.K. report their beverage consumption over multiple 24-hour periods, and then they studied their genes to see if there were any links between them and any bitter or sweet beverage preference.

They found that preference for bitter beverages was genetics-related, but really didn’t come down to taste at all. Genetic factors that alter a person’s response to caffeine or alcohol likely lead to someone reaching for the drink as a treat, rather than the actual taste. So it was a positive response to the psychoactive properties in bitter drinks like beer and coffee—say, for instance, if it made them feel more energetic—that kept people refilling their mugs.

“They have a stimulating effect,” Marilyn Cornelis, Ph.D., assistant professor in the department of preventive medicine, told Bicycling. “You might not like the taste of coffee, but you might like the way it makes you feel.”

Usually, people tend to avoid bitter things—when something is bitter, it’s typically a warning sign to avoid it, Cornelis explained, because as our ancestors discovered, it may be poisonous.

Instead, when it comes to bitter drinks like coffee and beer, how they affect us and our genetics come into play. For example, people who metabolize caffeine quickly are more likely to consume more coffee, not necessarily because they enjoy the taste of the brew, but because they want to keep the caffeine buzz going.

One surprising finding was that people with a variant in the FTO gene—one typically related to a lower risk of obesity—actually preferred sugar-sweetened drinks, which seems counterintuitive. Sugar-sweetened drinks, like sodas, are loaded with sugar and caffeine, and don’t have the bitter taste of coffee, but do have the same psychoactive effects, meaning they can give you an energy jolt.

So it’s possible that people with that genetic variant can get hooked on the effects of caffeine at a younger age before they start drinking the more-bitter coffee (which, unless we are talking about fancy coffees loaded with flavor syrups, will be less caloric). Even though the gene variant is linked to lower chances of obesity, continuing to drink more and more sugary beverages to get that same jolt can eventually put them at risk of weight gain and the health problems that come with it.

Bottom line: While you may enjoy the psychoactive effects from your favorite afternoon coffee or happy hour beer thanks to your genetics, it’s important to play the moderation game to make sure you are not going overboard.

The Centers for Disease Control and Prevention (CDC) recommends no more than one alcoholic drink, or about a 12-ounce glass of beer or a 5-ounce glass of wine, per day for women and two drinks for men. Max out your caffeine at no more than 400 milligrams (mg) a day, or roughly five cups of coffee, according to the U.S. Food and Drug Administration. As for sugary drinks, the American Heart Association recommends no more than six teaspoons per day of added sugar for women and nine teaspoons per day for men. The average can of soda has about 10 teaspoons, so you may want to swap out your sodas for some non-caloric substitutions like unsweetened ice tea or water.

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