Tea or coffee? The answer might be genetic

Henrietta Strickland
November 17, 2018

To their surprise, people with genetic sensitivity to bitterness seemed to associate coffee with happiness more than others who were less sensitive.

The reasoning is all about our genetic predisposition to bitterness - in short, whether we find some substances more bitter than others will put us in one particular hot drink camp.

The participants with gene variants that made them taste the caffeine more strongly, known as caffeine "super-tasters", were 20 per cent more likely than the average person to be heavy coffee drinkers.

But, importantly for tea drinkers everywhere, that doesn't make them right.

The study was led by Jue-Sheng Ong and Liang-Dar Hwang at the QIMR Berghofer Medical Research Institute and the University of Queensland in Australia. Scientists have found the answer may in fact come down to your genes.

The findings suggest that variations in bitter taste perception resulting from genetic differences may help to explain why some people have preferences for coffee, tea or alcohol.

For quinine and PROP, the team confirmed their hypothesis.

"You'd expect that people who are particularly sensitive to the bitter taste of caffeine would drink less coffee", Marilyn Cornelis, senior author of the study, said in a statement. This makes flawless sense, given the evolutionary reasons humans are sensitive to bitter tastes in the first place: It's adaptive to not eat bitter things that might be under-ripe or poisonous.

Many of them, particularly those sensitive to PROP also drank less alcohol - and more specifically, tended to avoid red wine.

But their study of more than 400 000 people in the United Kingdom found that the more sensitive people are to the bitter taste of caffeine, the more coffee they drink.

How could this be?

"Most of us probably have anecdotal experience (or common sense) on how our taste influences what we drink, and now we can proudly say that there's some genetic evidence to support such a link", said Ong, in an email.

Not only that, the presence or absence of these genes determines how many cups of coffee or tea we throw back a day.

The effect of increased caffeine sensitivity was small: it only amounted to about two tablespoons more coffee per day.

But genes likely aren't the only factors driving people's tastes.

"Bitter taste perception is shaped by not only genetics but also environmental factors", he said.

Dr Marilyn Cornelis, co-author of the research from Northwestern University in IL, said: "The study adds to our understanding of factors determining beverage preferences - taste, in particular - and why, holding all other factors constant, we still see marked between-person differences in beverage preference as well as the amount we consume". "I guess you can say it's one of many factors and there's a genetic component to it".

Other reports by Click Lancashire

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