How people perceive bitter substances - which is associated with having a certain set of genes - has an impact on whether their preferences of coffee, tea or alcohol, according to a study in Scientific Reports.

Jue-Sheng Ong, Liang-Dar Hwang and colleagues analysed genetic variants associated with the perception of three bitter substances - propylthiouracil [PROP], quinine and caffeine - to evaluate the effect of bitterness perception on the intake of coffee, tea and alcohol in a sample of more than 400,000 UK Biobank participants.

The researchers found that a higher sensitivity to the bitterness of caffeine (determined by the presence of certain genes) was associated with increased consumption of coffee, whereas higher sensitivity to the taste of PROP and quinine was associated with lower consumption of coffee. Higher sensitivity to the bitterness of caffeine was also associated with a higher likelihood of being a heavy coffee drinker. The inverse was found for tea intake, where higher sensitivities to PROP and quinine were associated with higher intake, but higher sensitivity to caffeine was associated with lower intake. For alcohol, a higher intensity of PROP perception resulted in lower consumption, whereas higher perception of the other two compounds had no clear influence.

The findings suggest that differences in bitter taste perception resulting from genetic differences may help to explain why some people are coffee drinkers while others prefer tea.