Coffee drinking habits could be genetic, study finds

Why do some people need to drink more coffee to feel the same effect? It could be down to a gene that controls cells' ability to process caffeine, scientists have found.

Published inNature journal, the gene PDSS2 has been cited by researchers as the reason why those that have it tend to consume less coffee to get the same caffeine hit.

PDS22 appears to interfere in the body’s ability to breakdown caffeine, causing it to stay in the body for longer.

Coffee is associated with both beneficial and adverse effects on the body and these findings could better identify individuals’ optimum coffee consumption.

Similar actions, in which an individual’s ‘safe’ level of caffeine intake could be better determined, may also apply to other drinks containing the stimulant, including sodas and energy drinks.

Study details

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How coffee is drunk in the Netherlands compared to Italy was the reason for the difference in the final results. ©iStock/easy_company

The study gathered researchers from Scotland, Italy and the Netherlands. Here, they assessed the genetic profile of 370 subjects living in Puglia in southern Italy.

Another sample group consisting of 843 subjects living in the Friuli Venezia region in north east Italy were also enrolled. All subjects completed a survey that asked about their coffee consumption.

Researchers discovered that subjects with a genetic variation of PDSS2 drank approximately one less cup of coffee than those without the variation.  

When the same study was repeated on a group of 1731 subjects in the Netherlands, the results mirrored that of the Italian population but coffee consumption was slightly more in those who had the gene variation.  

The team attributed this observation to how coffee is drunk in each country. In Italy, smaller drinks such as espresso were more popular. In contrast, residents of the Netherlands tended to consume larger drinks that contain more caffeine.

"The results of our study add to existing research suggesting that our drive to drink coffee may be embedded in our genes,” said Dr Nicola Pirastu, the study’s lead author and a chancellor's fellow at the University of Edinburgh's Usher Institute.

“We need to do larger studies to confirm the discovery and also to clarify the biological link between PDSS2 and coffee consumption."

Genes driving coffee intake

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“Our results have highlighted a novel gene associated with coffee consumption adding new information towards understanding the genetic drivers of coffee consumption.” ©iStock/ratmaner (ratmaner/Getty Images/iStockphoto)

Research into the genetic basis of coffee consumption has implicated a number of genes including CYP1A1-CYP1A2, AHR, NRCAM and ULK3.

A recent study involving over 120,000 people confirmed the influence of CYP1A1-CYP1A2 and AHR and the existence of 6 new genes.  

The team hypothesized that while CYP1A2 genotype is important in determining coffee consumption at higher caffeine intakes, PDSS2 may have a role at lower levels.

“Our results have highlighted a novel gene associated with coffee consumption adding new information towards understanding the genetic drivers of coffee consumption,” the study stated.

Although further studies on larger cohorts will be needed to confirm our findings we believe to have added an important piece to the understanding of the genetic basis of coffee consumption and potentially to the mechanisms regulating caffeine metabolism.

Researchers from the Italian coffee company Illy also participated in the project though the company did not offer financial support.

Source: Nature Scientific Reports

Published online ahead of print, doi:10.1038/srep31590

“Non-additive genome-wide association scan reveals a new gene associated with habitual coffee consumption.”

Authors: Nicola Pirastu et al.