A new study analyzed genetic variants associated with the perception of bitter substances to evaluate tea, alcohol, and coffee consumption.
For most people, starting the day before a cup of coffee is not an option. For some, getting through a day takes up to three to five cups of coffee. Coffee drinkers usually do not associate coffee with a bitter taste. Neither is drinking coffee perceived as being associated with one’s genetics. However, recent studies are proving otherwise.
What makes coffee and tea taste bitter?
Coffee and tea contain bitter substances that contribute to their strength, body, and bitter taste. Bitter-tasting caffeine is a component of both tea and coffee, while another bitter molecule known as quinine adds bitterness to the already bitter coffee. Although human beings have an aversion to bitter tasting foods that keep us from eating poisonous things, drinking coffee and tea defies that rule. Is it possible, then, that a liking for the taste of bitter coffee is written in our DNA?
The factors that influence coffee consumption
There are several factors that influence an individual’s coffee consumption. For instance, the level of stress, the number of urgent deadlines at work or sleep quality the night before are factors that may decide how much coffee you drink on a particular day. But caffeine dependence and a liking of the bitter taste of coffee is influenced by another important factor: your genetics.
The genetics behind coffee consumption
A new study published in the Scientific Reports analyzed the genetics associated with the perception of bitter substances and consumption of coffee, tea, and alcohol among more than 400,000 participants in the United Kingdom. The researchers used Mendelian randomization technique that is commonly used in epidemiological studies of a disease, to test the causal relationship between the bitter taste of coffee, tea, and alcohol with the consumption of these beverages.
This study used genetic variants linked to the perception of caffeine, quinine, and PROP, which is a synthetic bitter-tasting compound. These genetic variants were identified in a previous genome-wide analysis of solution taste ratings in the Australian twins study. The scientists tested the association between these genetic variants and self-reported consumption of coffee, tea, and alcohol in the participants of this study.
The higher the sensitivity to bitter coffee taste, the more coffee consumption
The taste of coffee is not just a factor of chance or circumstance. This study shows that coffee tasting is heavily influenced by one’s genetics and the sensitivity to the bitter taste is caused by a genetic variation. The results of this study showed that people with a high perceived intensity of caffeine had a higher consumption of coffee.
The more sensitive an individual is to the bitter coffee taste, the more coffee he or she will drink. Contrary to what one would expect, the results of this study show that a higher sensitivity to bitterness is associated with a heightened fondness of the bitter taste.
Strong coffee tasting may be associated with heavy coffee consumption
The researchers suggest that the effect of perception on a person’s daily coffee consumption may be small but significant. A strong coffee taster may be 20% more likely to become a heavy coffee drinker as compared to a normal caffeine taster. This could translate to more than four cups of coffee per day for people who are strong coffee tasters.
The relationship between bitter taste perception and tea and alcohol intake
The results showed that a higher perceived sensitivity to PROP and quinine was associated with an increased intake of tea. On the other hand, a higher sensitivity to PROP was associated with lower alcohol consumption. Furthermore, the researchers found that increased sensitivity to PROP and quinine was associated with low coffee intake and a lower risk of becoming a heavy coffee drinker.
Listen to your body to make the choice
The results of this study highlight how our genetics govern some aspects of our lives. It is interesting to note that drinking coffee and tea is largely dictated by our genes. It is no wonder then that coffee drinking can make some people uncomfortable for hours while others enjoy the taste of coffee and can drink a pot to themselves.
In conclusion, this study shows that bitter beverage consumption is associated with differences in bitter taste perception. The consumption of coffee and tea is a way of life for many people. However, it can have a significant impact on health and disease.
The association between genetic variants and bitter beverage consumption needs to be further investigated. In the meantime, one should account for these genetic differences and listen to the body for making a choice between drinking coffee or tea.
Written by Preeti Paul, MS Biochemistry
Reference: Jue-Sheng Ong et al., Understanding the role of bitter taste perception in coffee, tea and alcohol consumption through Mendelian randomization. Scientific Reports (2018) 8:16414|DOI:10.1038/s41598-018-34713-z