Next time you’re chugging down your fourth cup of coffee just to have enough energy to get anything done, blame your genes. A new study suggests that how we metabolize coffee – and in turn, how much we need to drink to get the brew’s positive effects – maybe be genetic, with some people requiring more caffeine to get a good buzz than others.
In the study, published last week in the journal Scientific Reports, researchers conducted a genome-wide association study comparing over 1,200 Italians to 1,731 people in the Netherlands. Based on this assessment, the research team discovered a significant association between the PDSS2 gene and how much coffee people reported drinking: the greater the expression of the gene, the less coffee subjects drank. “The hypothesis is that people with higher levels of this gene are metabolizing caffeine slower, and that’s why they’re drinking less coffee,” study author Nicola Pirastu of the University of Trieste in Italy said according to TIME. “They need to drink it less often to still have the positive effects of caffeine, like being awake and feeling less tired.”