The widespread Asian habit of chewing 'betel-quid' can cause cancer, even when it is chewed without tobacco, according to a new review by the World Health Organisation's International Agency for Research on Cancer (IARC).
A previous evaluation in 1985 found that chewing the substance — a combination of a type of vine leaf, areca nut, and slaked lime — can cause cancer of the mouth, pharynx and oesophagus when it is chewed with tobacco. But the new review concludes that chewing betel-quid alone can cause cancer of the mouth, and that chewing areca nut can result in a pre-cancerous condition known as oral submucous fibrosis.
Hundreds of millions of people across Asia chew betel-quid for its stimulant effect, to satisfy hunger, and to freshen the breath. In recent years, the arrival of a variety of commercial betel-quid and areca-nut products on the world market — combined with aggressive marketing campaigns — has increased their usage.
Oral cancers are more common in parts of the world where betel-quid is chewed, according to the review. For example, in Taiwan and China the incidence of oral cancer in men has tripled over the past 20 years, coinciding with a steep rise in the number of men who chew the substance.