Native to the northeast coast of Brazil, cashew was domesticated long before the arrival of Europeans at the end of the fifteenth century. It was "discovered" by European traders and explorers and first recorded in 1578. It was taken to India and East Africa, where it soon became naturalized.
Recorded Medicinal history:
The cashew tree and its nuts and fruit have been used for centuries by the indigenous tribes of the rainforest (Peruvian and Brazilian), and it is a common cultivated plant in their gardens.
In Africa, the bark and leaves of the tree are used medicinally; fruit juice and a bark tea are very common diarrhoea remedies used by curandeiros and indigenous people alike. Caju infusions and teas of the bark are used to treat diabetes, weakness, urinary disorders, and fevers.
In South America, the leaves and/or the bark are used in for eczema, psoriasis, scrofula, dyspepsia, genital problems, and venereal diseases, as well as for impotence, bronchitis, cough, asthma, vaginitis, intestinal colic and syphilis-related skin disorders.
North American practitioners use cashew for diabetes, coughs, bronchitis, tonsillitis, intestinal colic, and diarrhoea, and as a general tonic.
Traditional Medicinal Uses:
Caju contains naturally occurring analogs of the latest diabetes drugs pioglitazone (Actos) and rosiglitazone (Avandia), without their potential for liver damage or weight gain.
Benefits of caju for specific health conditions include the following:
Diabetes. Laboratory tests suggest that cajueiro lowers blood sugar by inhibiting the action of an enzyme known as tyrosinase. When tyrosinase is blocked, receptor sites on cells in the intestines become more sensitive to insulin. Insulin "instructs" the cells to absorb more of the amino acids leucine, phenylalanine, tyrosine, and valine. With higher concentrations of these amino acids in the body, the body suffers less protein breakdown and wasting caused by uncontrolled diabetes. This protects against kidney damage. While animal studies show caju to have only a weak anti-diabetic effect, the herb is useful because it carries no risk of toxic damage to cell DNA.
Parasitic infection. In the Barna region of Brazil, 65 percent of cases of leishmaniasis, an ulcerating skin disease, are successfully treated with caju.Caju extracts are over 90 percent effective against the parasites that cause schistosomiasis (bilharzia).