Cashew nuts are the stone fruits of the cashew tree, which grows to a height of up to 12 m and belongs to the sumach family (Anacardiaceae).

Cashew nuts are shell fruit (nut types). Because of their similar characteristics with regard to transport, particularly their high oil content, their requirements regarding care during storage and transport are the same as those of oil-bearing seeds/fruits.

This is surrounded by a fine, brown seed coat, which contains antioxidants which protect the kernel from penetration by atmospheric oxygen so preventing it from becoming rancid (oxidative rancidity).

Cashew is a multi-purpose tree of the Amazon, and is frequently found rowing wild on the drier sandy soils in the central plains of Brazil and cultivated in many parts of the Amazon rainforest. It grows up to 15 meters in height and has a thick and tortuous trunk and branches so winding that they frequently reach the ground. The cashew tree produces many resources and products. The bark and leaves of the tree are used medicinally, the cashew nut has international appeal and market value as a food, and even the shell around the nut is used medicinally and has industrial applications in the plastics and resin industries for its phenol content. Then there is the "cashew fruit." The cashew fruit is very peculiar as it really isn't a fruit at all. It is actually a swollen peduncle that grows behind the real fruit which yields the cashew nut. This large pulpy and juicy part is a pseudo-fruit with a fine sweet flavor and is commonly referred to as "Cashew Fruit" or the Cashew "apple." Fresh or frozen cashew fruit concentrate is a common juice product found at food stores in South America. The cashew nut grows externally in its own kidney shaped hard shell at the end of this pseudo-fruit or peduncle. The nut kernel inside is covered with an inner shell and between the two shells is a thick caustic toxic oil called "cardol" which will raise blisters on the skin. Cashew nuts must be cleaned to remove the cardol and then roasted to remove the toxins before they can be eaten.

Native to the northeast coast of Brazil, Cajueiro was domesticated long before the arrival of Europeans at the end of the fifteenth century. It was "discovered" by Europeans and first recorded in 1578, and from there taken to India, then to East Africa where it soon became naturalized in those countries. In sixteenth century Brazil, cashew fruits and their juice were taken by Europeans to treat fever, to sweeten breath, and to "conserve the stomach." The cashew tree, its nuts and fruit have been used for centuries by the Indigenous Tribes of the rainforest, being a common cultivated plant in their gardens. The Tikuna tribe in northwest Amazonia considers the fruit juice to be medicinal against influenza and brew a tea of leaves and bark for diarrhea. The Wayãpi Tribe in Guyana use a bark tea for a diarrhea and/or colic remedy for infants. Tribes in Suriname use the toxic seed oil as worm medicine to kill bot-fly larvae under the skin In Brazil, a bark tea is used as a douche for vaginal secretions or as an astringent to stop bleeding after a tooth extraction.> Dr. James Duke reports that the green fruits are used to treat hemoptysis, the seed oil and fruit juice is used for warts, a leaf infusion is used for diarrhea, expectorants are made from the tender shoots, and wine made from the fruit is used as an antidysenteric in other parts of the Amazon rainforest. The fruit juice and bark tea are a very common diarrhea remedy throughout the Amazon today, used by Curanderos and local people alike.

In Peruvian herbal medicine today, Cajueiro leaf tea (called Casho) is employed as a common diarrhea remedy, a bark tea used as a antiseptic vaginal douche, and the seeds are used for skin infections. In Brazilian herbal medicine the fruit is taken for syphilis, as a diuretic, stimulant, and aphrodisiac, a leaf tea for a mouthwash and gargle for mouth ulcers, tonsilitis and throat problems, and for washing wounds, an infusion and/or maceration of the bark is used to treat diabetes, asthenia, muscular debility, urinary disorders, and asthma. The leaves and/or the bark are also used in Brazil for eczema, psoriasis, scrofula, dyspepsia, genital problems and venereal diseases, impotency, bronchitis, cough, intestinal colic, leishmaniasis, and syphilitic-related skin disorders. North American practitioners use Cajueiro for diabetes, cough and bronchitis, tonsilitis, intestinal colic, diarrhea, and as a general tonic. The uses of Cajueiro and its many products cover a wide range of uses, even it's "fruit." In addition to being delicious, it is a rich source of vitamins, minerals and other essential nutrients. It has up to five times more vitamin C than oranges and a high amount of mineral salts. Besides making highly nutritive snacks and juices, Cashew fruit extracts are now being used in body care products. Because of its high amount of vitamin C and mineral salts, Cashew fruit is used as coadjutant in the treatment of premature aging of the skin and to remineralize the skin. It is also a good scalp conditioner and tonic, often used in shampoos, lotions and scalp creams due to the conditioning activity of its proteins and mucilage.
The bark and leaves of Cajueiro are a rich source of tannins, a group of phytochemicals with physiological activities. These tannins have demonstrated an anti-inflammatory effect and are astringent in nature which may be one of the reasons Cajueiro is effective in cases of diarrhea. Another group of phytochemicals named anacardic acids are found in Cashew with the highest concentration found in the nut shells. Several clinical studies has shown that these chemicals exhibit tyrosinase inhibitory activity, have molluscacide properties, and are cytotoxic to certain cancer cells. It's antimicrobial properties were documented in a 1982 clinical study and its effectiveness against leishmanial ulcers was documented in two clinical studies.

Antidysenteric, Anti-inflammatory, Antitussive, Aphrodisiac, Astringent, Diuretic, Febrifuge, Hypoglycemic, Hypotensive, Purgative, Refrigerant, Stomachic, Tonic, 4-0-methylglucuronic-acid, Alanine, Alpha-catechin, Alpha-linolenic-acid, Aluminum, Anacardic-acid, Anacardol, Antimony, Arabinose, Arginine, Arsenic, Ascorbic-acid, Aspartic-acid, Barium, Benzaldehyde, Beta-carotene, Beta-carotene, Beta-sitosterol, Boron, Bromine, Cadmium, Calcium, Capric-acid, Caprylic-acid, Cardanol, Cardol, Cesium, Cystine, Europium, Fluorine, Folacin, Gadoleic-acid, Galactose, Gallic-acid, Gingkol, Glucose, Glucuronic-acid, Glutamic-acid, Glycine, Hafnium, Hexanal, Histidine, Hydroxybenzoic-acid, Iron, Isoleucine, Kaempferol-glycoside, L-epicatechin, Lauric-acid, Leucine, Leucocyanidin, Leucopelargonidine, Limonene, Linoleic-acid, Lysine, Magnesium, Manganese, Methionine, Mufa, Myristic-acid, Naringenin, Niacin, Oleic-acid, Oxalic-acid, Palmitic-acid, Palmitoleic-acid, Phenylalanine, Phytosterols, Potassium, Proline, Protein, Pufa, Quercetin-glycoside, Riboflavin, Salicylic-acid, Samarium, Scandium, Selenium, Serine, SFA, Silicon, Squalene, Stearic-acid, Strontium, Sulfur, Tannin, Thiamin, Threonine, Titanium, Tocopherol, Trans-hex-2-enal Tryptophan, Tyrosine, Valine, Vanadium, Zinc.