Love for coffee and chocolate turns out to be genetic

News

08 May 2025, 11:24

Genes that speed up caffeine metabolism were found to be responsible for the love of coffee and dark chocolate. At the same time, the craving for an extra cup is not connected with the taste of coffee itself, its richness or notes of nutmeg in the aroma. The brain simply associates bitterness with vigor. And because caffeine is quickly absorbed, its effect lasts less in such people. As a result, a reflex is formed that pushes you to drink more coffee and eat dark chocolate.

“People equate the natural bitterness of caffeine with a stimulant effect,” said study author Marilyn Cornelis, an assistant professor of preventive medicine and nutrition. “They learn to associate the bitterness with caffeine and a feeling of alertness. We see a learned effect. When people think of caffeine, they think of bitterness, so they enjoy dark coffee and dark chocolate.”

To find out how this mechanism works, the scientists analyzed more than 126,000 questionnaires from the British Biobank, as well as data from large American studies. Survey participants shared their food and drink preferences, including whether they add sugar or milk to their coffee. All participants were genotyped, and the researchers had complete data on their DNA. The scientists then compared this data and identified patterns between the subjects' genes and their food preferences.

New data can significantly influence further research. Consumption of coffee and dark chocolate reduces the risk of developing Parkinson's disease, cardiovascular disease, type 2 diabetes and some types of cancer. Recently, scientists have found that just 3-4 cups of coffee a day reduces the risk of developing chronic liver disease. Dark chocolate reduces the risk of heart disease. However, the studies include people with and without the "coffee lover" mutation, which may affect the results.

“Drinking black coffee and coffee with cream and sugar has a very strong impact on your health,” says Cornelis. “A person who wants black coffee is different from a person who wants coffee with cream and sugar. Based on our findings, a person who drinks black coffee also prefers other bitter foods, such as dark chocolate. So we are delving into a more precise way to measure the real health benefits of this drink and other foods.”

An earlier study found that people who are genetically predisposed to love coffee drink less tea. At the same time, people who are more sensitive to coffee bitterness drink less alcohol.