29 April 2021

Coffee genes espresso themselves

The Back Page

Along with chocolate and red wine, coffee has proven to be a happy hunting ground for researchers in pursuit of their 15 minutes of media fame.

This shouldn’t surprise. There’s an awful lot of capitalistic enterprise invested in keeping caffeine addicts such as your Back Page correspondent hanging out for his next shot of arabica.

But is this hankering for a daily cup of Joe or two down to ubiquitous marketing, or does our genome also play a role? Quite possibly the latter, say researchers at the University of South Australia.

In a study of nearly 400,000 folks, these boffins say they have found “causal genetic evidence that cardio health … influences coffee consumption”.

Using data from the UK Biobank, the researchers examined the habitual coffee consumption of 390,435 people, comparing this with baseline levels of systolic and diastolic blood pressure, and baseline heart rate. Causal relationships were determined using Mendelian Randomisation.

What they discovered was that people with high blood pressure, angina, and arrhythmia were more likely to drink less coffee or decaffeinated coffee or avoid coffee altogether than those without such symptoms, and that “genetics actively regulate the amount of coffee we drink and protect us from consuming too much”.

“People subconsciously self-regulate safe levels of caffeine based on how high their blood pressure is, and this is likely a result of a protective genetic mechanism,” lead researcher Professor Elina Hyppönen said in a media release.

“What this means is that someone who drinks a lot of coffee is likely more genetically tolerant of caffeine, as compared to someone who drinks very little,” Professor Hyppönen said.

“Whether we drink a lot of coffee, a little, or avoid caffeine altogether, this study shows that genetics are guiding our decisions to protect our cardio health.

“If your body is telling you not to drink that extra cup of coffee, there’s likely a reason why.”