Paan was invented by Scholars of Aruvedas with the help of Dhanvantari thousands of years ago after taking experiment on rats. Paan was found out good for digestion Even reference of Paan is found in Shrimad Bhagavatam as Lord Krishna used to chew. This evidence is of 5000 years ago.
Paan is chewed as a palate cleanser and a breath freshener. It is also commonly offered to guests and visitors as a sign of hospitality and as "ice breaker" to start conversation.
It also has a symbolic value at ceremonies and cultural events in India.