Caffeine quest buried in genes?

If you drain your first coffee of the day while instantly planning for your next one, that quest for a caffeine hit might be due to your genes.

As part of an in-depth new study, researchers at the University of Edinburgh and the University of Trieste, Italy, looked at the DNA of around 3000 coffee drinkers in the Netherlands and Italy.

The researchers asked participants to record how many cups they drank a day, and matched the results against who out of the survey participants had gene PDSS2 — a variation that reduces the body’s ability to break down caffeine.

The survey found Italian people with the DNA variation consumed, on average, one less coffee a day than those without it. Those in the Netherlands were less affected by the gene difference.

Gene PDSS2 is thought to reduce the body’s ability to break down caffeine, causing it to stay in the system for longer. Those without the gene variation tend to metabolise caffeine faster, and are more likely to keep reaching for extra cups throughout the day.

Experts suspect the difference between the coffee drinkers could be down to the type of coffee. In Italy smaller cups like espresso are preferred, while in the Netherlands, they like larger cups that tend to contain more caffeine.

Dr Nicola Pirastu, from the University of Edinburgh, told the Daily Mail the results added to existing research suggesting our drive to drink coffee may be embedded in our genes.

The study was published in the journal Scientific Reports.