From nature, we should all be well away from coffee. The bitterness is in fact linked to poisonous and harmful substances: it is for this reason that we are far from most of the foods that have this flavor. Yet over the centuries coffee has conquered the hearts of many people. How is it possible? Scientists at Northwestern University have a possible answer.

US researchers have studied the relationship between genes, bitter sensitivity and preference between coffee and tea. The subjects most sensitive to the bitter taste are also those that consume more coffee. The predisposition to appreciate the bitterness of coffee would in fact be the result of experiences of positive reinforcement. The more coffee you drink, the more you feel energetic and positive, the more you appreciate the drink. How did scientists arrive at this conclusion?

The study analyzed the bitterness and drink consumption of 400,000 individuals. Scientists have looked for genetic variants that influence the bitterness of three substances: caffeine, quinine, and PROP. Caffeine is the substance contained in coffee, quinine gives the bitterness to tonic water and the PROP mimics the bitterness of cabbage and broccoli. Later, scientists compared data with the consumption of coffee, tea and alcohol.

The subjects most sensitive to bitter caffeine preferred coffee to tea. Those more predisposed towards quinine and PROP, instead, avoided the coffee. People most sensitive to PROP also tended to avoid alcohol, especially red wine.

Source: focus.it