'Coffee drinking habits may be written in our DNA'

Researchers have identified a gene that appears to curb caffeine consumption, a finding which may explain why some people tend to drink fewer cups of coffee.
The study by researchers at University of Edinburgh in the UK found that people with a DNA variation in a gene called PDSS2 tend to drink fewer cups of coffee.
The findings suggest that the gene reduces the ability of cells to breakdown caffeine, causing it to stay in the body for longer.
This means that a person would not need to consume as much coffee to get the same caffeine hit, researchers said.

The findings add to previous studies that have identified genes linked to coffee habits and shed new light on the biological mechanisms of caffeine metabolism.
Researchers looked at genetic information from 370 people living in a village in south Italy and 843 people from six villages in north-east Italy.

Each of the participants was asked to complete a survey that included a question about how many cups of coffee they drank each day.
Researchers found that people with the DNA variation in PDSS2 tended to consume fewer cups of coffee than people without the variation. The effect was equivalent to around one fewer cup of coffee per day on average.

Researchers replicated the study in a group of 1,731 people from the Netherlands. The result was similar but the effect of the gene on the number of cups of coffee consumed was slightly lower.
This could be because of the different styles of coffee that are drunk in the two countries, researchers said.
"The results of our study add to existing research suggesting that our drive to drink coffee may be embedded in our genes," said Nicola Pirastu from University of Edinburgh.
The findings were published in the journal Scientific Reports.