In 2003, the International Agency for Research on Cancer (IARC), part of the World Health Organization, determined from the newest research and experimental evidence that the leaves and flowers of Piper betle, betel nuts themselves, and lime were all Group 1 carcinogens.
更進一步的是，2003 年 WHO 所屬的 IARC（國際癌症研究中心）綜合各種最新研究和實驗確認，除荖葉外，不論是檳榔仔或添加的荖花、紅灰、白灰，都屬於「第一級致癌物」，毒上加毒，致癌威力可想而知。