The carcinogens in betel nut are primarily polyphenols and alkaloids. In the alkaline environment created by the lime paste, they create cancer-causing free radicals and nitrosamine. As early as 1999, research by Veterans 'General Hospital showed that betel nut containing lime paste and wrapped in betel flowers (the flowers of the betel plant Piper betle, not of the betel palm) activated cancer cells.
所謂檳榔的致癌物質，主要是指檳榔（菁仔）中的多酚類化合物和生物鹼等，在與紅灰、白灰混合而成的鹼性環境下會產生致癌的自由基或亞硝基胺；而早在 1999 年榮總的研究就發現，夾「荖花」（藤本植物荖藤的花）的紅灰檳榔，的確有啟動癌細胞的作用。