For centuries, hundreds of millions of people across Asia, from Pakistan to Palau, have chewed the spicy date-like fruit of the betel palm for a quick buzz. Then four years ago, a World Health Organisation study found that chewing betel nuts can cause oral cancer and that the rate of these malignant mouth tumours was highest in Asia where the betel nut is a widely used stimulant.
Despite the cancer link, betel nut addicts are chewing on in many parts of Asia. But in Taiwan, the findings have spurred a government health campaign against the nut, which is grown on palm trees across the sub-tropical island south-east of China.
"If you don't want oral cancer, the most direct way is to quit chewing betel nuts," Wu Chien-yuan, chief of cancer prevention in the Taiwan health ministry, told Reuters.
Betel nut, which contains an addictive stimulant similar to nicotine, is widely used in parts of Southeast Asia, India, Pakistan and the South Pacific as a breath freshener, a hunger antidote, a substitute for cigarettes and as a way to get high.
Users often chew it all day long, causing all sorts of unpleasant side-effects such as red-stained teeth and pavements covered with red spittle as many users spit out the betel nut's remnants as they chew.
"Whether it harms you is an individual thing," said Kaohsiung betel chewer Wan Chin-hsian, 35. "It's healthy to spit it out." Under pressure from the government health drive, betel nut traders and growers are seeking new uses for the nut such as soap, as the industry seeks to stay in business.
There is a lot at stake for betel nut growers as the nut is the island's second biggest crop after rice and provides more than 20,000 jobs. "Betel nut is in dispute, but the sellers still have to make a living," said Lee Su-ming, an organiser of a betel nut festival in the southern Taiwan City of Kaohsiung last month.