Betel Nut

BETEL NUT

Betel nut, the seed of the betel palm (Areca catechu ), is one of the most widely used substances in areas of the western Pacific and parts of Africa and Asia. It is prepared with other substances as a mixture for chewing and is used as a mild stimulant by more than 200 million people.

References to betel nut appear in ancient Greek, Sanskrit, and Chinese texts from more than a century b.c. Ancient historic documents of Ceylon refer to its use, and its prevalence in Persia by 600 a.d. is documented by Persian historians. Its use in different parts of the Arab world by the eighth and ninth centuries is also well documented, and it had become an important aspect of the economy and social life in India, Malaysia, the Philippines, and New Guinea. Betel was probably brought to Europe by Marco Polo, around 1300; it soon proved to be an important commodity in the western Pacific and a source of tax revenue for the Dutch in the mid-1600s.

PATTERNS OF USE

The mottled brown-and-gray betel seeds are gathered before they ripen during the period between August and November. They are boiled in water, cut into slices and dried in the sun, becoming dark brown or reddish in color. This betel seed, or nut, becomes the primary ingredient in the betel nut chewing mixture ("quid"), which is made up of several ingredients. While the component substances differ in different parts of the world, all the preparations contain fresh chunks or dried powdered forms of the betel nut. Mixtures prepared for children frequently contain only the husk of the nut, while the full strength form for adults always has the nut itself.

The second ingredient of the quid is usually a form of peppermint or mustard, or the leaf, bean and/or bark of the shrub-like or climbing pepper plant vine (Piper betel ). The third component is slaked lime, which is usually produced from limestone or by burning sea shells or coral stones in the presence of water. This process produces calcium hydroxide, usually used as a white powder. While all betel-nut quids contain some of the three main components, other ingredients, such as spices, dyes, and aromatics are frequently added. In India, tobacco is mixed with the quid. The combination of nut, mustard or vine, lime, and other ingredients create an alkaline, bitter-tasting mixture that is chewed, forming a red paste which stains the teeth, mouth, gums, and lips, and generating large amounts of saliva. Like tobacco chewers, betel-nut chewers spit out the excess juices.

Some habitués chew betel nut all day long. Others use it as part of social custom, not unlike the use of Kava, or of the consumption of Alcohol in Western countries. In some areas of the world, such as Papua New Guinea, betel-nut mixtures are often offered as a before-dinner "appetizer" or as an after-dinner treat. Like kava, in many places, sharing betel-nut mixture is important in courtship and marriage customs and in establishing friendships.

ACTIVE INGREDIENTS

The major active ingredient of betel nut is arecoline, present in a concentration estimated to be 0.25 percent. The mixture also contains small amounts of pilocarpine and muscarine. These three ingredients are all natural plant products that act in the body in a manner similar to the normal brain Neurotransmitter acetylcholine. In the presence of calcium hydroxide, arecoline is also converted to another psychoactive substance, aredaidine.

Chewing betel nut produces immediate effects that in some ways resemble those of Nicotine, but which are likely to continue for hours. These include euphoria and feelings of general arousal and activation, perceived by the user as a decrease in tiredness and a blunting of feelings of irritability.

Other prominent effects are also related to the acetylcholine-like actions. These include sweating, increased production of saliva, and an increase in breathing rate and lacrimation (tearing of the eyes). Effects on the digestive tract include a decrease in appetite and, especially if the drug is taken on an empty stomach, diarrhea. All these effects can be blocked by atropine, a type of anti-acetylcholine drug.

Some of the active ingredients in betel nut are used in modern pharmacological treatment in the Western world. Betel-nut preparations have been used in Western society as a purgative and in veterinary medicine as an agent for treating worm infestation in animals. Probably the most interesting use appears around 1842, when betel nut was included in toothpastes in England. It was touted as an important way to prevent decay, a claim that may or may not be accurate, although much larger doses than those found in toothpastes would be required to really be clinically effective. It was also said that this ingredient would help strengthen the tooth enamel and remove tartar, claims of questionable value. In view of the fact that betel, as it is commonly used, stains the teeth dark red to black, is thought to cause tooth decay, and can cause serious lesions of the mouth and throat, it is curious that it should have appeared in Western society in preparations for dental care.

SOME DANGERS

The acetylcholine-type drugs, especially muscarine, can be deadly when taken in high doses. In fact, muscarine is the active ingredient causing some forms of lethal mushroom poisoning, but it is unlikely that the mixture of any of the plant products in betel-nut preparations are potent enough to cause lethal overdose. Regular "recreational" use of betel nut is, however, responsible for a number of adverse health consequences that can contribute to the risk for early death.

The most prominent dangers associated with betel-nut chewing are probably the result of a combined effect of the active ingredients and the lime on the gums. The first and most frequently observed physical changes are white plaques appearing on the mucosal lining of the mouth or on the tongue. These are precancerous lesions (leukoplakia) that often lead to the development of very aggressive and serious tumors (squamous cell carcinoma), which can subsequently invade muscles and bone tissue. The prevalence of this cancer among regular betel-nut users is estimated to be as high as 7 percent. Potentially lethal cancers may also develop in the esophagus. Chronic use may also cause oral submucous fibrosis—a form of fiber formation (fibrosis) that usually starts just beneath the gums and may involve the back of the throat and the pharynx. The problem is estimated to be seen in at least mild form in up to 50 percent of chronic betel-nut chewers. This condition usually has a very slow onset, and if use continues it is irreversible, untreatable, and likely to become progressively more severe. The major finding involves a loss of elasticity of the tissue lining the mouth, which causes stiffness that can become so severe as to interfere with eating. Associated problems are a burning sensation in the mouth, ulcers or blisters on the lining of the mouth, decreased sense of taste, and dryness of the mouth lining.

There is little doubt that betel-nut substance can produce fairly intense psychological dependence. Individuals can develop a pattern of constant use, feeling unhappy and incomplete if they cannot get their betel nut. They are also likely to feel they cannot work properly without it, and may spend a great deal of money and time obtaining and using betel-nut mixtures. It is not clear, however, that there is a prominent and identifiable form of physical withdrawal associated with cessation of use.

Betel-nut consumption can be viewed as a public-health hazard in parts of the world where its use is prevalent, because, at least theoretically, the habit of spitting the juice on the street can increase the spread of diseases such as tuberculosis.

(See also: Plants, Drugs from )

BIBLIOGRAPHY

Beecher, D., et al. (1985). Betel nut chewing in the United States, Journal of the Indiana Dental Association, 64, 42-44.

Ford, C. S. (1967). Ethnographical aspects of kava. In D. H. Efron, B. Holmstedt, & N. S. Kline, (Eds.), Ethnopharmacologic search for psychoactive drugs. PHS Publ. No. 1645. Washington, DC: U.S. Department of Health, Education, and Welfare.

Lewin, L. (1964). Phantastica: Narcotic and stimulating drugs. New York: Dutton.

Schuckit, M. A. (1992). Betel Nut: A widespread drug of abuse. Drug Abuse & Alcoholism Newsletter, 21 (1). San Diego: Vista Hill Foundation.

Schullian, D. M. (1984). Toothpastes containing betel nut from England of the 19th century. Journal of History of Medicine, 39, 65-68.

Talonu, N. T. (1989). Observations of betel nut use, habituation, addiction and carcinogenesis. Papua New Guinea Medical Journal, 32, 195-197.

Taufa, T. (1988). Betel nut chewing and pregnancy. Papua New Guinea Medical Journal, 31, 229-233.

Marc A. Schuckit

Jerome H. Jaffe