Betel nut---actually a seed---is a stimulant produced by the Areca catechu tree. It is traditionally chewed in combination with betel leaf and lime in Asian countries, where it is valued for its stimulant effects.
Betel nut is a symbol of marriage in Vietnam and has been used by Indian royalty since the pre-Vedic period. Despite its natural origin and long history of use, betel nut may cause side effects when used excessively or with other mind-altering substances. Understanding the side effects of betel nut is necessary to make an informed decision about its use.
One of the most obvious physical signs of frequent betel chewing is staining of the skin and teeth. When handled, betel nut may stain the hands and can cause permanent black discoloration of the teeth when chewed frequently over long periods of time.
The development of oral cancer is among the most serious side effects of betel nut. According to Wiley Interscience Journal, frequent use of betel nut leads to significant increases in chromosome abnormalities and an increased risk of developing oral cancer.
Other factors that may increase cancer risks include use of caustic lime, which is frequently added to betel nut in a preparation called "paan," and tobacco.
The only way to completely avoid the risks of chewing betel nut is to abstain from using the substance altogether. Limiting your use to no more than two times per month and avoiding other risk factors such as smoking may help reduce these risks for those who decide to use betel nut.
Due to its psychoactive effects, which are similar to those of nicotine and caffeine, betel nut may have the potential to cause tolerance, dependence and withdrawal. The positive effects of betel nut, which generally include increased energy, alertness and stamina, may lead to repeated use and resulting dependence. Since long-term and frequent use of betel nut is associated with oral cancer, dependence can be hazardous.
Source: http://www.livestrong.com (By Tracii Hanes)