Here's How Your Genes Make You A Tea Or Coffee Lover: But Too Much Caffeine May Be Harmful

According to a study led by researchers from US-based North-western University and QIMR Berghofer Medical Research Institute in Australia, fondness for tea or coffee lies in our genetic predisposition towards bitter tastes. It could be because bitterness acts as a natural warning system to protect us from harmful substances. The study published in the journal Scientific Reports, explored reactions to three bitter substances -- caffeine, quinine and propylthiouracil (PROP) -- to understand how they affect people's preference for drinking tea, coffee and alcohol. The findings showed that people who were more sensitive to caffeine and were drinking a lot of coffee consumed low amounts of tea. In other words, people who have a heightened ability to taste coffee's bitterness -- and particularly the distinct bitter flavour of caffeine -- learn to associate "good things with it."

"You'd expect that people, who are particularly sensitive to the bitter taste of caffeine would drink less coffee. The opposite results of our study suggest that coffee consumers acquire a taste or an ability to detect caffeine due to the learned positive reinforcement (stimulation) elicited by caffeine." said Marilyn Cornelis, Assistant Professor of Preventive Medicine at North-western University Feinberg School of Medicine. The study also found that people sensitive to the bitter flavours of quinine and of PROP -- a synthetic taste related to the compounds in cruciferous vegetables -- avoid coffee. "The findings suggest our perception of bitter tastes, informed by our genetics, contributes to the preference for coffee, tea and alcohol," said Cornelis.

Scientists applied Mendelian randomisation -- a technique commonly used in disease epidemiology -- to test the causal relationship between bitter taste and beverage consumption in more than 4,00,000 men and women in the UK.

Coffee and tea are known to be healthy beverages. However, having too much caffeine may also be harmful for our health; here's why:
 

• Anxiety: Consuming caffeine in low-to-moderate dose can increase alertness, but having it in larger amounts may lead to anxiety or edginess. Monitor your own response in order to determine how much you can tolerate.
   
• Insomnia: Caffeine helps you to stay alert and awake during the day; however, it may negatively impact your sleep quality and quantity too. Don't consume caffeine after early afternoon to avoid sleeping problems.
   
• Digestive Issues: According to health experts, small-to-moderate amounts of coffee or tea may improve gut motility; however, larger amounts may lead to loose stools. Reducing the intake of your coffee or teal may be beneficial.
   
• High Blood Pressure: Caffeine is known to raise blood pressure when consumed in high doses or prior to exercise, as well as in people who rarely consume it. However, this effect may only be temporary, so it's best to monitor your response.

 
Light-to-moderate intake of caffeine may provide impressive health benefits to many people. However, very high dosage may lead to side effects that interfere with day-to-day living and might even cause serious health issues.

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