Betel leaves are an essential item in any Hindu event, social or religious. It is offered to God, forms the base for any dakshina for the Guru or as a post-meal item.
If our ancestors had given pride of place for this humble leaf in all the functions, there must be something about the betel leaves. A quick search on the web threw up this site which claims a dozen benefits of chewing betel leaves.
According to this site, www.healthsite.com chewing paan or betel leaves, improves digestion, protects against oral carcinogenesis and helps maintain oral hygiene. Betel is used as an aphrodisiac (ahem!), and for treating ulcers, warts, boils, diabetes, cough, wounds and constipation (with castor oil per rectum).
Whew! That is a long list.