"While the effect of perception on your daily coffee intake might be relatively small - only a 0.15 cup per day increase - from a normal caffeine taster to a strong caffeine taster, it actually makes you 20% more likely to become a heavy drinker - drinking more than four cups per day", said Jue Sheng Ong, first author of the research from QIMR Berghofer Medical Research Institute in Australia. Quinine is another substance that contributes to the bitterness of coffee, and is also found in tonic water.
"Our taste genes partially play a role in how much coffee, tea or alcohol we drink", he said.
A recent study by my colleagues and I revealed bitter taste receptor genes that are responsible for the perception of caffeine, quinine and a human-made bitter substance propylthiouracil (PROP). While logically, we should want to spit it out because of the bitterness.
People who are more sensitive to coffee's acrid, bitter taste ironically like it more.
Co-author Professor Marilyn Cornelis, of Northwestern University Feinberg School of Medicine in the United States, said: 'You'd expect that people who are particularly sensitive to the bitter taste of caffeine would drink less coffee.
We knew from previous research that inherited factors play a role in the amount of coffee and tea a person drinks a day, and that the ability to digest caffeine plays an important role in the people's consumption of caffeinated beverages.
The team applied Mendelian randomization - a technique commonly used to study disease - to test the causal relationship between bitter taste and beverage consumption.
Researchers said the findings for tea were harder to explain but might in part be down to heavy coffee drinkers tending to be very light tea drinkers.
Ong added the findings for tea might be down to tea containing lower concentrations of bitter substances, meaning it might prove more acceptable than coffee to those with heightened perception of bitterness.
These genetic variants were then tested for associations with self-reported consumption of coffee, tea and alcohol in the current study.
When there is a need for caffeine, "super-tasters" of quinine and PROP could choose tea over coffee because they tend to be more sensitive to overall bitterness. Even if as a child or right now you dislike the bitterness of coffee or tea, you may have noticed that your taste and dietary behaviour change over time as you grow.
But we can't blame everything on your genes.
So, even if you carried the "wrong" genes in terms of tasting bitter flavours, you could still learn to enjoy deliciously bitter-tasting foods and beverages. Read the original article.