Many people, all over the world start their day with a cup of morning coffee.
It’s one of the most popular drinks, often used to start the day or keep energy up during work or study.
But not everyone’s body handles coffee the same way. Some people can drink a lot and feel fine. Others get jittery or have trouble sleeping after just one cup. Scientists have been trying to understand why this happens.
A team from the University of Toronto, led by researcher Ahmed El-Sohemy, looked into how our genes affect the way we process caffeine—the main active ingredient in coffee. Caffeine is a natural substance that makes you feel more awake and alert.
But once it enters your body, your system has to break it down and remove it. That job mainly falls on your liver, and how fast this happens depends on your genes.
Genes are like tiny instruction books inside your body. They tell your body how to make proteins that do all sorts of important work. One of these genes is called CYP1A2 which helps your liver break down caffeine.
Some people have a version of this gene that works quickly, so, these people can drink three or four cups of coffee a day without much issue. Their bodies get rid of the caffeine fast, so it doesn’t build up and cause problems.
But others have a slower version of this gene. Their bodies take longer to break down caffeine. For them, drinking too much coffee can be hard on their system, especially on the kidneys.
The kidneys are organs that help filter your blood. They remove waste and extra fluids, and they help keep your body’s chemicals balanced. If your body is slow at handling caffeine, drinking too much coffee might put extra stress on your kidneys. That’s why scientists often say that three cups of coffee per day is a safe amount for most people.
This research, shared in the medical journal JAMA Network Open, could help more people understand how their bodies function. It also opens the door to learning more about how our genes affect how we react to food, drinks, and even medicine.