- Cashew Nut Shells
Cajueiro (botanical name Anacardium occidentale) is an evergreen tree found in the tropical regions and belongs to the plant family which also includes mango, poison oak and poison ivy. Although cajueiro is indigenous to Brazil, it now grows in all regions of the world having tropical climatic conditions. This tree grows up to a height of 30 feet (10 meters) and produces big oval-shaped leaves. Cajueiro bears flowers that have a yellow hue with pink stripes and emerge on the extended stems. The fruit of cajueiro is basically a coagulated stem. However, the actual fruit of this tree is found immediately under the thickened part of the stem and it encloses red or yellowish flesh that envelops the cashew nut. After the bark or shell of the nut is removed, it is mainly used as a food.
As mentioned earlier, cajueiro is indigenous to the northeast coast of Brazil, people in the region had domesticated (started cultivating) cashew much before the Europeans arrived in the country around the end of the 15th century. Later, the European traders as well as explorers ‘discovered’ and also documented cashew in 1578. From Brazil, cajueiro was taken to India as well as East Africa and it became naturalized in these places soon.
Cajueiro has a number of medicinal uses and is available in the form of a tincture. This tincture is effective for treating diabetes, but in this case the patients need to have patience before the results are evident. It would take a minimum of three to four weeks before the favorable results of low blood sugar are noticed. Nevertheless, diabetics using this tincture should measure their blood sugar levels every day to ensure that the combination of the prescribed insulin and/ or additional medications with cajueiro does not reduce the blood sugar levels too much. The shell of the cajueiro cashew encloses natural oil that may result in irritation of the skin provided it is not heated earlier to remove much of the caustic property of the oil. Hence, it is advisable that you should never consume raw cashew. However, they are safe after they are roasted in their shell.
The bark, “fruit,” nuts, and resin of the tree.
Apart from its fruits being edible, cajueiro encloses analogs of the recent diabetes medicines pioglitazone (Actos) and rosiglitazone (Avandia). However, these natural analogs do no have the possibility for resulting in weight gain or harming the liver. In South American tribal medicine, cajueiro is used for several therapeutic purposes, for instance as a contraceptive, a remedy for snake bites and also for treating vaginitis (inflammation of the vagina) and eliminating parasites from the body.
The medical condition specific advantages of cajueiro are many and some of them are discussed below.
Examinations in the laboratory have hinted that cajueiro also helps to lower blood sugar levels by slowing down the activities of an enzyme called tyrosinase. When the actions of tyrosinase are obstructed, the receptor sites on the intestinal cells turn out to be additionally sensitive to insulin. In effect, insulin ‘directs’ the cells to soak up added amino acids leucine, tyrosine, phenylalanine and valine. When the concentration of these amino acids is high in the body, the body experiences lesser breakdown of protein as well as wasting due to uncontrolled diabetes. This action aids in protecting the kidneys from any harm. Although studies conducted on animals have shown that cajueiro only possesses a feeble anti-diabetic impact, this herb is particularly effective as it does not carry any risk of damaging the cell DNA.
Cajueiro is successfully employed to treat about 65 per cent cases of leishmaniasis, a form of skin ulcer, in the Barna region of Brazil. In effect, extracts obtained from cajueiro are more than 90 per cent successful in treating medical conditions attributable to parasites and those that result in schistosomiasis (also known as bilharzias).
The juice extracted from the fruit bark as well as the nut oil of cajueiro are considered to be equally effective traditional medication to treat corns, calluses, warts, elephantiasis and also ulcers that are cancerous. It has been proved that anacardol acid and anacardic acid present in cajueiro extracts are somewhat effective against Walker carcinosarcoma 256. A decoction prepared with the astringent fruit bark of cajueiro is prescribed for people who are experiencing acute diarrhea and thrush. Old leaves of this tree are applied topically for skin problems as well as burns. An oily material obtained from the pericarp of cajueiro is used to treat ruptures on the feet. Cuna Indians are known to have employed the bark to prepare an herbal tea to cure asthma, colds and nasal congestion. The seed oil of cajueiro is considered to be alexeritic as well as amebicidal (any substance that kills ameba) and is used to cure malaria, gingivitis and syphilitic ulcers.
The ancient Indian form of medicine Ayurveda advocates the use of cajueiro fruit for treating a number of health conditions, including dysentery, fever, leucoderma, tumours, ascites, absence of appetite and persistent ulcers. According to Ayurveda, the fruit of this tree is considered to be an aphrodisiac and anthelmintic (any substance capable of eliminating parasitic worms). People in the Gold Coast use the leaves and bark of this tree to cure tender gums as well as toothache. The juice of cajueiro fruit is employed to treat hemoptysis (expectoration of bloody mucus). On the other hand, people in Cuba use the resin from the tree to cure cold. Cajueiro also shows hypoglycemic (lowering blood sugar to exceptionally low levels) actions. In Malaya, people prepare a decoction with the bark to treat diarrhea, while people in Indonesia use the older leaves in the form of a poultice to treat burn injuries and various skin complaints. The juice extracted from the “apple” is employed to treat quinsy (suppurative tonsillitis) in Indonesia, while it is used to cure dysentery in the Philippines.
In the 16th century, cashew fruits as well as the juice extracted from them were taken internally by European settlers in Brazil to cure fever, improve their breath as well as to protect the stomach.
For several centuries, the native tribes of the rain forests have used the cashew tree, its fruits and nuts and currently it is a common plant grown in their gardens. In northwest Amazonia, the Tikuna tribe believes that the juice extracted from the cashew fruit possesses therapeutic properties and is effective in treating influenza. In addition, they also brew an herbal tea with the leaves and bark of cashew trees to cure diarrhea. Similarly, in Guyana, the Wayãpi tribe uses the herbal tea prepared with cashew tree bark to cure diarrhea as well as colic among infants. Several tribes in Suriname topically apply the noxious seed oil of cajueiro to eliminate worms, especially larvae of botfly beneath the skin. People in Brazil prepare an herbal tea with the bark of the tree and use it in the form of a douche for vaginal discharge as well as an astringent to stop bleeding following the extraction of a tooth. In addition, a wine is prepared using the cashew fruits and it is effective for treating dysentery in different regions of the Amazon rainforest. The juice of the fruit as well as the herbal tea prepared with the bark are both widespread medications for treating diarrhea all over the Amazon region now. This remedy is used by the local people as well as curanderos (folk healers) alike.
In the present day herbal medicine of Peru, cashew leaf tea (known as ‘casho’) is used as a common remedy for diarrhea, an herbal tea prepared with the bark of the fruit is used in the form of an antiseptic vaginal douche, while the seeds of the fruit are used to treat skin contagions. On the other hand, in the herbal medicine of Brazil, the cashew fruit is taken internally to treat syphilis and also in the form of a diuretic, an energizer and aphrodisiac (any substance that augments sex drive). A tea prepared with the cashew leaf is used as a mouthwash as well as a gargle for treating tonsillitis, mouth ulcers and throat problems. It is also used topically to wash injuries. The bark is also used to prepare an infusion or it is marinated to cure debility, diabetes, muscular weakness, urinary problems as well as asthma. In Brazil, the leaves and bark of cashew tree are used to treat psoriasis, eczema, dyspepsia, scrofula, venereal ailments, and genital problems. People in Brazil also use herbal formulations prepared with the leaves and bark of the tree to cure bronchitis, intestinal colic, cough, impotence, leishmaniasis (an infection attributed to a protozoan belonging to the genus Leishmania) as well as skin problems associated with the sexually-transmitted disease (STD) syphilis. Practitioners of herbal medicine in North America employ cashew to treat bronchitis, coughs, tonsillitis, diabetes, diarrhea, intestinal colic as well as a common stimulant/ energizer.
The cashew tree is useful for several purposes and different parts of the tree are used. When the cashew ‘apple’ (fruit) is completely mature and enlarged, it may be consumed raw or conserved in the form of sweetmeat or jam. The juice extracted from the fruit is used to make a beverage called ‘Brazil cajuado’ and also fermented to prepare a wine, which also possesses therapeutic properties.
Cashew fruits or seeds may be consumed in various ways – as a whole, shelled and salted and also roasted. It may be blended in chocolates or used in Madeira wine. When the roasted fruits are shelled, it yields cashew nut which is available commercially. Cashew seeds yield approximately 45 per cent of pallid yellowish, bland edible oil which has resemblance to almond oil. Black, sour/ pungent and potent vesicant oil is extracted from the shell or hulk of the nuts that is used in the form of an additive and also as a water-proofing agent in insulted polishes, in brake linings, in making typewriter rolls, in oil-proof and acid-proof tiles and cements, for termite-proof timbers and also as an exceptional grease in magneto frameworks in airplanes. The timber of cashew tree is employed in making furniture, packing cases, building boats as well as in charcoal production. The bark of the tree is used in tanning. The stem of cashew trees gives off a clear gum, known as Cashawa gum, which is made use of in pharmaceuticals and also as an alternative to gum arabic.
The color of the juice extracted from cashew fruit changes to black when exposed to air and is used to make an ineffaceable ink. In the coastal Orissa in India, shelter belts and wind breaks that have been planted to make the sand dunes stable and shield the nearby fertile agricultural land from drifting sand, have resulted in economic cashew crops following five years of their planting.
Habitat and cultivation
Generally, the germination process of cashew is very sluggish and poor. In effect, many nuts are normally placed inside a hole dug into the ground and thinned afterwards. Usually, cashew is propagated by seeds, but some people also propagate the tree in a vegetative manner by grafting, inarching or air-layering. Cashew should be planted in situ (permanent position) since the seedlings of cashew are difficult to transplant. However, when the plants are established they require little or no care.
During the initial few years of the growth of the plants, intercropping is possible along with peanut, cotton or yams. The cajueiro plants bear fruits three years after their plantation. The lower branches of the tree as well as the suckers are got rid of when the cajueiro begins to bear fruits. The trees yield full production when they are about 10 years old and keep on bearing fruits till they are approximately 30 years old. In arid regions, such as Tanzania, the trees flower during the dry season and the fruits ripen within two to three months.
Cashews that are propagated by seeds and seedlings are likely to produce flowers by the second year of their existence and when they are below three feet high. Cajueiro trees grow very well in an assortment of soil condition provided they have a good drainage. It is important to shield the young cajueiro/ cashew trees from low temperatures as they might be harmed or even killed at temperature as low as 32°F. On the other hand, the older and established trees may suffer considerable damage due to frost or freeze, but generally manage to recover soon. When the trees are planted outdoors, they ought to be positioned in secluded areas cosseted by trees that are able to endure more cold or buildings for most favourable or optimal growth.
It is important to fertilize the cashew trees once in every three to four months using superior quality nourishments that are used for the fruit bearing trees. Although cashews are able to endure extreme drought conditions, they generally grow much better when they are provided with usual irrigation. It may be mentioned that very few or virtually no pests infest the cashew trees. Nevertheless, thrips may sometimes attack foliage during the arid spring season and result in some amount of defoliation.
The anti-microbial attributes of cashew were recorded for the first time in an in vitro study conducted in 1982. Findings of another research were published in 1999 which hinted that cashew possessed excellent anti-microbial properties, which were especially effective against Pseudomonas and E. coli. More lately, in 2001, a study found that an extract of the cashew bark showed anti-microbial activity against 13 of 15 microorganisms examined in vitro. Earlier, in 1999, scientists stated that the fruit of cajueiro or cashew showed anti-bacterial actions against Helicobacter pylori, a Gram-negative bacterium that is currently thought to be the reason behind sever stomach ulcers and gastritis. Its efficacy against leishmanial ulcers (ulcers of the skin) was also recorded in two other studies. To conclude, two other researches – one conducted on mice and the other on rats in 1989 and 1998 respectively – record the defending property of an extract obtained from cajueiro leaves against diabetes induced among the animals in the laboratory. While the leaf extract did not function as hypoglycemic like some others, the extract helped to stabilize the blood glucose levels close to the levels before the test.
Chemical analysis of the ripened cajueiro seed has shown that it encloses carbohydrates, proteins, calcium, fiber, iron, magnesium, riboflavin, thiamine, niacin and also ascorbic acid. The fruit of the tree encloses water, carbohydrates, fat, proteins, iron, calcium, vitamin C and carotene. The oil extracted from the shell of the cashew encloses approximately 90 per cent of anacardic acid. In addition, it also contains glycerides, lionoleic, stearic, palmitic and lignoceric acids as well as sitosterol.
Collection and harvesting
It takes approximately three months from the time the flowers appear on the cajueiro tree to the ripening of its fruits. Completely ripened cajueiro fruits drop to the ground where the ‘apple’ or fruit becomes dry. In damp weather conditions, the fruits are collected every day and subsequently dehydrated for anything between one to three days. Although people have tried to dry the fruits by mechanical means, those attempts have proved to be failures and, therefore, it is done by manual labor. Generally, cashews are roasted within their shells with a view to make them fragile and oil-free, broken up and the nuts removed and subsequently vacuum packed. In several parts of India, people collect the nuts directly from the trees growing in the wild to add to their paltry income from other crops that are cultivated on less fertile land. Skilled people are employed to extract the kernels by cracking the shells using wooden hammers, but without splitting the kernels. Subsequently, the nuts are detached from the fleshy pedicel (small stalk) and receptacle, the coating of the seed removed using hands and the nuts are dried. It may be noted that the fresh green colored cashew nuts from the islands off the southern coast of India as well as Africa are usually shipped to plants in western India for processing.
- From Wilson – Aug-10-2017
- I use cashews as a healthy snack. These nuts are packed with nutritious vitamins and minerals. Since I have been eating cashews I haven’t had any problems with constipation and my skin is glowing.