Bunch of Areca nut or betet nuts are hanging on from the palm ready for harvest in Kerala, India. The areca nut is the seed of the areca palm (Areca catechu), which grows in much of the tropical Pacific, Asia, and parts of east Africa. It is commonly referred to as betel nut, as it is often chewed wrapped in betel leaves (paan). The International Agency for Research on Cancer concluded that chewing areca nut is carcinogenic to humans after reviewing the published medical research. Various compounds present in the nut, most importantly arecoline, contribute to histologic changes in the oral mucosa. As with chewing tobacco, its use is discouraged by preventive efforts. The areca nut is not a true nut, but rather a drupe. It is commercially available in dried, cured and fresh forms. While fresh, the husk is green and the nut inside is soft enough to be cut with a typical knife. In the ripe fruit, the husk becomes yellow or orange and, as it dries, the fruit inside hardens to a wood-like consistency. At that stage, the areca nut can only be sliced using a special scissors-like cutter (known as aḍakattera in Telugu, adake kattari in Kannada,bajjeai in Tulu, adakitta in Marathi, puwak in Sinhala, jaanti in Bengali, adakka in Malayalam, pakku in Tamil, sarautaa in Hindi, guaa in Oriya, and sudi in Gujarati). Usually for chewing, a few slices of the nut are wrapped in a betel leaf along with calcium hydroxide (slaked lime) and may include clove, cardamom, catechu (kattha) and/or other spices for extra flavouring. Betel leaf has a fresh, peppery taste, but it can also be bitter to varying degrees depending on the variety. The combination of areca nut with betel leaf is called "goi" in (Bodo),tamul in Assamese, kavala in Kannada, tambulam in Sanskrit, bajjai in Tulu, and paan in Hindi, Marathi, Punjabi, and Urdu. Areca nuts are chewed with betel leaf for their effects as a mild stimulant, causing a warming sensation in the body and slightly heightened alertness, although the effects vary from person to person. The effect of chewing betel leaf and areca nut together is relatively mild, and could be compared to that of drinking a cup of coffee. The areca nut contains the tannins arecatannin and gallic acid; a fixed oil gum; a little terpineol; lignin; various saline substances; and three main alkaloids — arecoline, arecaidine and guvacine — all of which have vasoconstricting properties. The betel leaf chewed along with the nut contains eugenol, another vasoconstrictor. Many chewers also add small pieces of tobacco leaf to the mixture, thereby adding the effect of nicotine, which causes greater addiction than the drugs contained in the nut and the betel leaf. In almost all parts of India, Sri Lanka and southern China, areca nuts are not only chewed along with betel leaf, but are also used in the preparation of Ayurvedic and traditional Chinese medicines. Powdered areca nut is used as a constituent in some dentifrices. Other medicinal uses include the removal
