Consumption of sugary drinks and alcohol has long been related to numerous diseases, so with this in mind, Marilyn Cornelis and colleagues at Northwestern University began looking for the source of our preferences by studying variations in genes related to taste. The team hoped to learn how our taste preferences could be exploited to influence people's diets, but instead, they found the answer was within genes connected to the psychoactive buttons these drinks push.
The study drew on data from approximately 370,000 adults from the UK Biobank and three US cohorts, and saw beverages categorized into two taste groups: bitter (coffee, tea, grapefruit juice, beer, red wine and liquor/spirits) and sweet (sugar-sweetened drinks, artificially sweetened drinks and other juices). Participants' beverage consumption was recorded using 24-hour dietary recall questionnaires, before a genome-wide association study of bitter and sweet beverage consumption was performed.
The researchers found that it is the psychoactive properties of the drinks that is responsible for a person's preference of sweet or bitter, rather than variations in one's taste genes, highlighting the difficulties people face when trying to alter their diets.
"People like the way coffee and alcohol make them feel – that's why they drink it – it's not the taste," says Cornelis. "The genetics underlying our preferences are related to the psychoactive components of these drinks."
The study also found a variant in one gene, known as FTO, is linked to sugary drinks. People with this variant, which has also been linked with a lower obesity risk, surprisingly preferred sugary drinks.
"It's counterintuitive," Cornelis says. "FTO has been something of a mystery gene, and we don't know exactly how it's linked to obesity. It likely plays a role in behavior, which would be linked to weight management."
In a previous Northwestern study on caffeine – conducted in conjunction with QIMR Berghofer Medical Research Institute in Australia – Cornelis found that the more sensitive people are to the bitter taste of caffeine, the more of it they drink.
"You'd expect that people who are particularly sensitive to the bitter taste of caffeine would drink less coffee," says Cornelis. "The opposite results of our study suggest coffee consumers acquire a taste or an ability to detect caffeine due to the learned positive reinforcement (i.e. stimulation) elicited by caffeine."
Which basically says we learn to associate the bitterness of coffee with the good feelings it triggers.
The team's latest study appears in Human Molecular Genetics.
Source: Northwestern University
