Betel nut

# Overview
Betel nut (Bettlenut), also known as Paaku, Pinang, Areca nut or Cau in Vietnamese and Supari in Bengali language, is the seed of the Betel palm (Areca catechu).  Betel nuts can be chewed for their effects as a mildly euphoric stimulant, attributed to the presence of relatively high levels of psychoactive alkaloids. Chewing it increases the capacity to work, also causes a hot sensation in the body; heightened alertness and sweating are an important and popular cultural activity in many Asian countries.  It is also used as an offering in Hinduism. In East and Nort-east India, Betel nut is chewed with Paan (Betel leaf). Betel nut and betel leaves are different in chemical compositions. Betel nuts contain arecaidine and guacine whereas the betel leaf oil contains a number of terpeneols.

# Uses

## Modern day consumption
In India (the largest consumer of betel nut), the betel nut is cut into small pieces using a special instrument called sarota, and the husk is wrapped in a "betel leaf" along with lime and may include clove, cardamom, catechu (kattha), etc. for extra flavouring.  Betel leaf has a fresh, peppery taste, but, depending on the variety of betel pepper from which it comes, it can be very bitter.  Experienced chewers might mix the betel nut with tobacco (the drug effect of the nicotine in tobacco resembles that of betel nut).  This preparation of betel leaf with or without betel nut is commonly referred to as paan in India and Pakistan, and is available everywhere.
Betel nut is also sold in ready-to-eat pouches called Pan Masala.  It is a mixture of many spices whose primary base is betel nut crushed into very small pieces.  Sometimes Pan Masala also includes a small quantity of tobacco; in this case, the product is called gutka.
Betel leaf is a different species of plant than the betel nut, and not in the areca family, but the Piper family (same as pepper and Kava).

## Tradition
Betel chewing is a tradition which dates back thousands of years.  The bitter poultice is an acquired taste, and, although it is not clear why the people of the Pacific originally began to chew betelnut, the habit has been passed down through the generations and now provides a cultural link to their past.
The betel and betel juice play an important role in many countries including Myanmar (where it is called kunya), the Solomon Islands and Vietnam.  The betel leaves and areca juices are used ceremonially in Vietnamese weddings.  Betel leaves and areca juices start the talk between the groom's parents and the bride's parents about the young couple's marriage.  The betel and areca are such important symbols of love and marriage that in Vietnamese the phrase "matters of betel and areca" (chuyen trau cau) is synonymous with marriage. There is a folk tale explaining the origin of this Vietnamese tradition.
In northeast India Betel leaves (pan) with a bit of lime and raw betel nut (called Tamul in Assamese, Sopari in Gujarati, and Kwai in Khasi) are consumed by a majority of the people. In Assam it is a tradition to offer Pan-tamul (Betel leaves and raw betel nut) to guests after tea or meals in a brass plate with stands called a Bota. In Assam betel nuts also have a variety of uses during religious and marriage ceremonies, where it takes on fertility symbolisms. It is also a tradition, especially in Upper Assam, to invite guests to wedding receptions by offering a few betel nuts with leaves.  During Bihu, the husori players are offered betel nuts and leaves by each household and their blessings are solicited.
The city Guwahati (guwa betel nut; haat market-place in Assamese) in Assam is named after this nut.
- Chamorro: pugua (Areca catechu), papulu (Piper betel), afok (lime)

## Betel chewing
Betel chewing is a part of many Asian and Pacific cultures and often takes place at ceremonies and gatherings, and preparation techniques vary from region to region.  The nut is either slivered or grated, often flavoured with spices according to local tradition, and usually wrapped in a betel leaf (note that betel leaf comes from the betel pepper plant Piper betle, which is not botanically related to the Betel Palm), along with some lime (calcium oxide or calcium hydroxide) to better extract the alkaloids.  Some people also chew tobacco with betel nut.  After about 20 minutes of chewing, the fibrous residue which remains of the nut is spat on the street, where it remains visible due to its characteristic bright red pigment.  Trails of bright red sputum lining the sidewalks are a sure indication of the popularity of betel chewing in an area. In Papua New Guinea and the Solomon Islands, fresh betel nut is sold on street corners, is chewed with a fresh leaf or 'fruit leaf' (daka in PNG) and mixed with lime.  In these countries, dried or flavoured betel nut is not popular.  Betel nut chewing has recently been introduced into Vanuatu where it is growing in popularity, especially in the northern islands of the country. In Guam, Betel nut (called Pugua'in the native Chamorro language) is a social pastime as a means to extend friendship, and can be found in many, if not most, large gatherings as part of the food display.

## Other uses
Powdered betel nut is used as a constituent in some tooth powders.  Other medicinal uses include the removal of tapeworms and other intestinal parasites by swallowing a few teaspoons of powdered betel nut, or by taking tablets containing the extracted alkaloids.

# Availability
In South Asia, betel nuts are often chewed as an ingredient in a snack called Paan.  Also popular in India is a concoction of ground (or thin sliced) betel nuts (supari), tobacco and flavourings known as gutka.  The Shimoga District in Karnataka is the largest producer of betelnut in India.
In Taiwan, betel nuts are known as binlang. Bags of 20 to 40 betel nuts are purchased fresh daily by a large number of consumers. To meet the steady year-round demand, there exist two kinds of betel nut shops, each of which sells cigarettes and drinks including beer in addition to their primary purpose of supplying betel nuts. On one hand, there are small mom and pop shops that are often poorly maintained and often do not stand out from other stores nearby. On the other hand, the second provides a sight unique to Taiwan. Such a shop often consists of nothing more than a single free-standing room, or booth, elevated one meter above the street that measures less than 3 meters by 2 meters. Large picture windows comprise two or more of the walls, allowing those who pass by a complete view of the interior. The interior is often painted brightly. Within such a shop, a provocatively dressed young woman can be seen preparing betel nuts (see betel nut beauty). Shops are often identified by multicolored (commonly green) fluorescent tubes or neon lights that frame the windows or that are arranged radially above a store. Customers stop on the side of the road and wait for the girls to bring their betel nut to their vehicles.
In the United States, betel nut is not a controlled or specially taxed substance and may be found in some Asian grocery stores. However, importation of betel in a form other than whole or carved kernels of nuts can be stopped at the discretion of US Customs officers on the grounds of food, agricultural, or medicinal drug violations. Such actions by Customs are very rare.
In the United Kingdom the betel nut is readily available in Asian grocery stores.

# Active compounds
The active chemical compounds of betel nut are arecaine and arecoline, alkaloids which are comparable to nicotine in its stimulating, mildly intoxicating and appetite-suppressing effects on the mind.  It also contains the alkaloids arecaidine, arecolidine, guracine (guacine), guvacoline and a number of others that have not yet been studied extensively.

# Effects on health

## Carcinogenicity
The International Agency for Research on Cancer (IARC) regards betel nut to be a known human carcinogen.  In countries and communities where betel is consumed extensively, there are vastly higher levels of oral cancer , and in Asian countries where it is consumed, oral cancer forms up to 50% of malignant cancers.  Betel nut chewers in Taiwan were found to have a twenty-eight times higher risk of acquiring oral cancer .  In addition, the mixing with chewing tobacco provides the same dangerous properties as normal chewing tobacco.  Although a substantial proportion of the cancers are caused by the tobacco rather than the betel nut and leaves in the quid, according to WHO, betel chewing without tobacco also leads to cancer of the mouth .  A British study reported in 2004 has tried to establish that there is a genetic aspect to this. Betel-nut chewers with faulty gene have higher risk of mouth cancer .

## Teeth
Regular betel chewing causes the teeth and gums to be stained red.  It is believed to reduce the incidence of cavities, and toothpastes were once produced containing betel extracts. However, the increase in mouth ulcers and gum deterioration (leading to total loss of teeth) caused by betel chewing outweigh any positive effects.

## Habit-forming
Betel chewing is addictive, and some practitioners consume vast quantities.  There is some alarming news released from the BHP (Bureau of Health Promotion) which shows that the habit of betel nut chewing is entering younger age groups and spreading across different professions.
The government of Pakistan has ruled that packets of betel nut must carry health warnings similar to those on cigarette packs, reports Asiaweek magazine. The magazine notes that millions of people in southern Asia are addicted to pan masala, a mixture of betel nut and various oils and other ingredients wrapped in a betel leaf. This is meant to be chewed. India had already placed warnings on packets of betel nut because of a reported link with cancer of the mouth. Children have also been known to choke to death on betel nut. Pakistans new laws will forbid the selling of betel nut to children under five years of age. At one stage during the early 2000 period betel nut was being offered in nightclubs in S.E Australia at an alarming rate. Prices ranged from $1-2 per nut. Its street name is "hurry".

## Other harmful effects
According to Medline Plus, "Long-term use has been associated with oral submucous fibrosis (OSF), pre-cancerous oral lesions and squamous cell carcinoma.  Acute effects of betel chewing include asthma exacerbation, hypertension, and tachycardia.  There may be a higher risk of cancers of the liver, mouth, esophagus, stomach, prostate, cervix, and lung with regular betel use.  Other effects can include a possible effect on blood sugar levels, possibly increasing the risk of type 2 diabetes.
When done regularly, betel chewing is considered likely to have harmful effects on health including cancers of the stomach and mouth and damage to gums. Whether this is due to, or exacerbated by, lime being used in betel preparations and the addition of tobacco (in the case of gutka) or other impurities is open to question. It is well known in betel consuming countries that various items, such as opiates and tobacco, can be added to betel preparations to increase the addictive properties, and thus to bolster sales.
Very few studies exist of the use of a "pure" paan preparation: betel nut, betel leaf, and lime, and fewer studies exist of betel nut alone.
Medical literature at this stage (even though highly anecdotal) seems to indicate that regular, addiction-driven use (for example, eight pinches a day) of betel nut in the preparations popular in India, Pakistan, New Guinea, and Taiwan can be harmful. Regarding the preparation methods used in Vietnam and Guam, and regarding occasional usage, there seems to be no strong indication one way or another.
Betal Nuts are known to be a high anti-thiamine factor.

## Positive effects
MedlinePlus indicates "poor-quality research" showing a possible beneficial effect for sufferers of anaemia during pregnancy.  However, it counsels against betel nut chewing due a possible risk of spontaneous abortions.  It also indicates "poor-quality studies" showing a possible beneficial effect on schizophrenia and for stroke recovery.

# Structure
According to the botanical classification, the betelnut tree belongs to the same family as oil palm and talipot palm, the Arecaceae, but their outer appearances are quite different.