areca nut areca nut the areca nut (/ˈærɪkə/ or /əˈriːkə/) is the fruit of the areca palm (areca catechu), which grows in much of the tropical pacific (melanesia and micronesia), south asia, southeast asia, and parts of east africa. it is commonly referred to as betel nut, not to be confused with betel (piper betle) leaves that are often used to wrap it (a preparation known as betel nut chewing). consumption has many harmful effects on health and is carcinogenic to humans. various compounds present in the nut, including arecoline (the primary psychoactive ingredient which is similar to nicotine), contribute to histologic changes in the oral mucosa. it is known to be a major risk factor for cancers (squamous cell carcinoma) of the mouth and esophagus. as with chewing tobacco, its use is discouraged by preventive efforts. consumption by hundreds of millions of people worldwide – mainly of south asian or southeast asian origins – has been described as a "neglected global public health emergency". areca nut etymology the term areca originated from dravidian languages, cognates of which are: malayalam: അടയ്ക്ക, romanized: aṭaykka kannada: ಅಡಿಕೆ, romanized: adike tamil: அடைக்காய், romanized: aḍaikkāy the terms dates back to the 16th century when dutch and portuguese sailors took the nut from india to europe. it is also known as elaus in palau. description areca fruits hanging from the palm. areca nuts in a market. areca nut plantation in india. areca nuts, also known as "betal nuts", plants in nepal. these types of nuts are commonly found in the terai region of nepal. betel nut saleswoman (vanimo, papua new guinea) the areca nut is not a true nut, but rather the seed of a fruit categorized as a berry. it is commercially available in dried, cured, and fresh forms. when the husk of the fresh fruit is green, 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. 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), 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. 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 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. tobacco leaf is often added to the mixture, thereby adding the effect of nicotine. in 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 traditional uses include the removal of tapeworms and other intestinal parasites by swallowing a few teaspoons of powdered areca nut, drunk as a decoction, or by taking tablets containing the extracted alkaloids. according to traditional ayurvedic medicine, chewing areca nut and betel leaf is a good remedy against bad breath. diplomat edmund roberts noted that chinese people would mix areca nut with uncaria gambir during his visit to china in the 1830s. after chewing a betelnut, the red residue is generally spat out. accordingly, places have banned chewing this nut to avoid eyesores. health effects systemic effects of areca nut areca nut affects almost all organs of the human body, including the brain, heart, lungs, gastrointestinal tract and reproductive organs. it causes or aggravates pre-existing conditions such as neuronal injury, myocardial infarction, cardiac arrhythmias, hepatotoxicity, asthma, central obesity, type ii diabetes, hyperlipidemia, metabolic syndrome, etc. areca nut affects the endocrine system, leading to hypothyroidism, prostate hyperplasia and infertility. it affects the immune system leading to suppression of t-cell activity and decreased release of cytokines. it has harmful effects on the fetus when used during pregnancy. garg et al. (2014) areca nut vendor with red mouth from areca consumption preparing betel leaves habitual chewers of betel leaf and areca nut have a greatly increased risk of developing a range of serious diseases, including cancers of the mouth and esophagus. it has many systemic effects (see box). chewing areca nut is a cause of oral submucous fibrosis, a premalignant lesion which frequently progresses to mouth cancer. according to medline plus, "long-term use has been associated with oral submucosal fibrosis (osf), pre-cancerous oral lesions and squamous cell carcinoma. acute effects of betel chewing include asthma exacerbation, hypertension, and tachycardia. there may additionally be a higher risk of cancers of the liver, mouth, esophagus, stomach, prostate, cervix, and lung with regular betel use. other effects can include altered blood sugar levels, which may in turn increase the risk of developing type 2 diabetes." use of areca nut has been associated with deterioration of psychosis in people with preexisting psychiatric disorders . areca nut consumption is also tied to chronic kidney disease in men as well as reports of milk-alkali syndrome. in 2003 the international agency for research on cancer (iarc), a world health organization sponsored group, found sufficient evidence that the habit of chewing betel quid, with or without tobacco, causes cancer in humans. in october 2009, 30 scientists from 10 countries met at iarc to reassess the carcinogenicity of various agents including areca nut, and mechanisms of carcinogenesis. they confirmed there is sufficient evidence that areca nut, with or without tobacco, can cause cancer. the harm caused by consumption of betel quid or areca nut by hundreds of millions of people worldwide (mainly with southern and eastern asian origins and connections) has been characterized as a "neglected global public health emergency". during pregnancy chewing paan (or other areca nut and betel leaf formulations) during pregnancy significantly increases adverse outcomes for the baby. the habit is associated with higher incidences of preterm birth and low birth weight and height. biologically, these effects may be a consequence of the arecoline that is found in areca nuts. the habit also exposes the fetus to various other toxic components linked to cancer. chemical composition the major alkaloid in betel nut is arecoline. there are other compounds, such as arecaidine, guvacine, isoguvacine, and guvacoline. tannins present in betel nut are mainly proanthocyanidins along with catechins and arecatannin. two new alkaloids were recently discovered and named acatechu a and acatechu b. several non-alkaloid compounds including benzenoids, terpenes, acids, aldehydes, alcohols, and esters were also identified. tradition areca nut and betel leaf consumption in the world. the oldest unequivocal evidence of betel chewing is from the philippines. specifically that of several individuals found in a burial pit in the duyong cave site of palawan island dated to around 2680±250 bce. the dentition of the skeletons is stained, typical of betel chewers. the grave also includes anadara shells used as containers of lime, one of which still contained lime. burial sites in bohol dated to the first millennium ce also show the distinctive reddish stains characteristic of betel chewing. based on linguistic evidence of how the reconstructed proto-austronesian term *buaq originally meaning "fruit" came to refer to "areca nut" in proto-malayo-polynesian, it is believed that betel chewing originally developed somewhere within the philippines shortly after the beginning of the austronesian expansion (~3000 bce). from the philippines, it spread back to taiwan, as well as onwards to the rest of austronesia and in neighboring cultures through trade and migration. chewing the mixture of areca nut and betel leaf constitutes an important and popular cultural activity in many south asian, southeast asian, east asian and oceanic countries. how or when the areca nut and the betel leaf were first combined into one psychoactive drug is not known. archaeological evidence from thailand, indonesia, and the philippines suggests they have been used in tandem for at least 4000 years. in vietnam, the areca nut and the betel leaf are such important symbols of love and marriage that in vietnamese the phrase "matters of betel and areca" (chuyện trầu cau) is synonymous with marriage. the tradition of chewing areca nuts starts the talk between the groom's parents and the bride's parents about the young couple's marriage. therefore, the leaves and juices are used ceremonially in vietnamese weddings. the folk tale explaining the origin of this vietnamese tradition is a good illustration of the belief that the combination of areca nut and the betel leaf is ideal to the point they are practically inseparable, like an idealized married couple. formerly, in both india and sri lanka, it was a custom of the royalty to chew areca nut with betel leaf. kings had special attendants whose duty it was to carry a box with all the necessary ingredients for a good chewing session. there was also a custom for lovers to chew areca nut and betel leaf together, because of its breath-freshening and relaxant properties. a sexual symbolism thus became attached to the chewing of the nut and the leaf. the areca nut represented the male principle, and the betel leaf the female principle. considered an auspicious ingredient in hinduism and some schools of buddhism, the areca nut is still used along with betel leaf in religious ceremonies, and also while honoring individuals in much of southern asia. a betel nut box crafted by the maranao people in the philippines. display of the items usually included in a chewing session: the betel leaves are folded in different ways according to the country and most have a little calcium hydroxide daubed inside. slices of the dry areca nut are on the upper left hand and slices of the tender areca nut on the upper right. the pouch on the lower right contains tobacco, a relatively recent introduction. areca nut cutter from bali, indonesia. areca nut in small packs, usually labelled as betel nut in south india. in assam, as well as most of its neighbouring northeastern states, areca nut is preferably consumed in its fermented form, which is supposed to make the fruit harder and sweeter. the raw nut may also be eaten during certain seasons when the fermented variety becomes unavailable, although it has more of ritual importance. standard sized pieces of the nut and leaf are usually consumed in combination with lime and a bit of tobacco. in assam, betel nut and leaf has indispensable cultural value; offering betel leaf and nut, (together known as gua) constitutes a part of social greeting and socialising. it is a tradition to offer pan-tamul (betel leaves and raw areca nut) to guests immediately upon arrival, and after tea or meals, served in a brass plate with stands called bota. in traditional assamese societies carrying a pouch of tamul-pan upon one's person during journeys or during farming activities, and sharing of the same, was an essential requirement. among the assamese, the areca nut also has a variety of uses during religious and marriage ceremonies, where it has the role of a fertility symbol. no religious ritual is complete without the offering of tamul-pan to the gods and spirits as well as to the assembled guests a tradition from upper assam is to invite guests to wedding receptions by offering a few areca nuts with betel leaves. during bihu, the husori players are offered areca nuts and betel leaves by each household while their blessings are solicited. spanish mariner álvaro de mendaña reported observing solomon islanders chewing the nut and the leaf with caustic lime, and the manner in which the habit stained their mouths red. he noted the friendly and genial chief malope, on santa isabel island, would offer him the combination as a token of friendship every time they met. in bhutan, the areca nut is called doma. the soft and moist raw areca nut is very potent. when chewed it can cause palpitation and vasoconstriction. this form is eaten in the lower regions