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Coffee Craving Is in the Genes

By Stephen Luntz

A large part of the coffee enthusiasts’ passion lies in an abundance of caffeine-craving genes.

Scientists at the Queensland Institute of Medical Research have estimated that 40% of coffee consumption is genetically determined. They’ve also made progress in discovering genes whose expression is affected by caffeine. It is hoped this will lead to an understanding of how caffeine protects against Parkinson’s disease.

Dr Enda Byrne says the work, published in Molecular Psychiatry, involved a meta-study of worldwide investigations of coffee drinking among fraternal and identical twins. Although the real aim of the research was to examine caffeine intake, Byrne says that coffee consumption was used as a proxy because some of the studies only examined this rather than total consumption.

Byrne acknowledges that determining the genetic component of variation in coffee consumption does not necessarily establish the level of genetic desire for a caffeine fix, since taste also has a genetic component. Nevertheless, a figure as high as 40% suggests that a large part of the coffee enthusiasts’ passion lies in an abundance of caffeine-craving genes.

Further research identified variant forms of genes that change the way caffeine is metabolised. Byrne says this may be related to insomnia and anxiety after coffee consumption.

“Our study found coffee consumption is not only influenced by genes, but caffeine can also affect the expression of genes,” Byrne says. “With caffeine impacting gene expression, we believe that caffeine then influences chemical pathways in the body. We also found a link between caffeine genes and other complex conditions, such as hypertension and Parkinson’s disease.”

The QIMR team examined cellular responses to caffeine, testing which genes were expressed. They observed enrichment of metabolic pathways in a group of genes that have previously been associated with Parkinson’s disease.

The finding offers hope of uncovering why high caffeine consumption reduces the risk of Parkinson’s disease by up to one-third, potentially stimulating treatments for those at risk of the neurological disease.