Are you a tea or coffee person? The answer may lie in your genetic predisposition towards bitter tastes say researchers. It could be because bitterness acts as a natural warning system to protect us from harmful substances. The study led by researchers from US-based Northwestern University and QIMR Berghofer Medical Research Institute in Australia 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