Addicted to Coffee? You Can Thank Your Parents for That

If you, like Lorelai Gilmore, would get a caffeine IV if it were possible, science may have an explanation for that.

Researchers have identified a gene that may be the reason why some people drink more coffee than others.

By analyzing populations of people in villages in Italy, researchers conducted a genome-wide association study in which they examined markers in DNA and identified a gene called PDSS2 that could play a role in caffeine metabolism.


The researchers asked more than 1,200 Italians how much coffee they drank and compared their consumption and genetic results to a population of 1,731 people in the Netherlands.

They found that people with greater expression of the PDSS2 gene also reported drinking less coffee.

“The hypothesis is that people with higher levels of this gene are metabolizing caffeine slower, and that’s why they’re drinking less coffee,” says study author Nicola Pirastu of the University of Trieste in Italy. “They need to drink it less often to still have the positive effects of caffeine, like being awake and feeling less tired.”

This study isn’t the first to find a connection between our genetics and our coffee habits. As TIME reports, an October 2014 study analyzed the genes of more than 120,000 coffee drinkers and found six genetic markers that were associated with a person’s responsiveness to caffeine.


Of course, if you remember from your high school biology class, you know that just because you might be predisposed to have a certain condition, this does not guarantee that you will have it. For instance, my mom is the kind of person who can have a cup of coffee before bed and have a perfectly good night’s sleep, whereas one strong cold brew in the morning can get my heart racing and keep me wired for the rest of the day.

Still, as genetic medicine continues to expand as a field, it’s pretty cool to see just how big a role our genes can play in all aspects of our lives. And while you might be quick to dismiss this particular research as the stuff of breakroom chatter, Pirastu says that “knowing the genotype of this gene may [also] explain why people react differently to different drugs.”

Who knew your Starbucks addiction could be so revealing? Go science.