The Science Behind Your Love for Coffee and Beer

It’s not as obvious as you may think — in fact, it’s in your genes.

by Lara DeSanto Health Writer

Why do some people love coffee and beer while others pucker up just thinking about them? The answer has nothing to do with how they actually taste, according to a new study from Northwestern University Feinberg School of Medicine.

Turns out our preference for sweet or bitter drinks is tied to genes that regulate how the beverages affect our minds, said Marilyn Cornelis, Ph.D., assistant professor of preventive medicine. "The genetics underlying our preferences are related to the psychoactive components of these drinks," said Dr. Cornelis, who’s also the lead author of the study. "People like the way coffee and alcohol make them feel. That's why they drink it. It's not the taste."

The research, published in Human Molecular Genetics, found that there are certain behavioral “rewards” to drinking these beverages. It makes sense: Coffee is known to be an energy-booster, thanks to the caffeine it contains. Beer, on the other hand, gives people that pleasant drunken buzz that so many enjoy, thanks to the alcohol content. (Cornelis even found one gene variant that made people significantly prefer sweetened drinks, which strangely is the same one linked to a lower risk of obesity.)

To conduct the study, different drinks were categorized into two groups: bitter (coffee, tea, beer, liquor, red wine, and grapefruit juice) and sweet (basically all other fruit juices and anything with added sugar or artificial sweetener). Researchers gathered data from 336,000 people about the drinks they consumed in a 24-hour period and compared that with information about each participants’ genetics.

Everything in Moderation

Genetics aside, you can keep on enjoying your coffees, beers, or juices--just don’t overdo it. If you’re a generally healthy person, experts say moderate alcohol use is probably not going to hurt you too much. In fact, some studies show that there are even benefits, such as possibly reducing your risk of diabetes. “Moderate drinking” equates to up to one drink a day for women of all ages and men over 65, and up to two drinks a day for men age 65 and under, according to the Mayo Clinic.

Examples of one alcoholic drink include:

  • Beer: 12 fluid ounces

  • Wine: 5 fluid ounces

  • Distilled spirits (80 proof): 1.5 fluid ounces

How much sugar to limit yourself to is a bit more complicated, according to Harvard Health — there aren’t really any studies touting the health benefits of sugar. That said, the American Heart Association suggests a limit of no more than 100 calories of added sugar per day (that’s about 6 teaspoons or 24 grams) for most women, and no more than 150 calories per day (9 teaspoons or 36 grams) for most men.

And thankfully, for us coffee addicts out there, this drink of choice actually has a bunch of health benefits, like reducing the risk of liver disease and pumping us full of cancer-fighting antioxidants.

What if You Need to Cut Back?

What if you were reading the above limits and thinking, “Uh oh?” Drinking too much alcohol, for example, is known to increase your risk of a slew of diseases, from cardiovascular disease to cancer, per the Mayo Clinic. And too much sugar ups your chance of developing diabetes, obesity, and heart disease.

Ready to try cutting back? Set a goal for yourself and keep track as you go, recommends the National Institutes of Health. Maybe you want to shoot for no more than three cocktails a week or one seltzer a day to help break a soda habit. Check out the Done app (iOS, free) which lets you set and track three goals (and more for a fee). One important note: Cutting back on alcohol can be especially hard if you’re used to drinking excessively, so you may want to reach out to your doc for help.

Lara DeSanto
Meet Our Writer
Lara DeSanto

Lara is a former digital editor for HealthCentral, covering Sexual Health, Digestive Health, Head and Neck Cancer, and Gynecologic Cancers. She continues to contribute to HealthCentral while she works towards her masters in marriage and family therapy and art therapy. In a past life, she worked as the patient education editor at the American College of OB-GYNs and as a news writer/editor at