What is marañón?
Marañón is the cashew tree, Anacardium occidentale. It gives two foods: the curved nut and the soft red or yellow cashew apple. In Latin America the leaves and bark were also brewed as folk remedies.
Most people meet it as a snack nut or as marañón juice. Folk use also covered leaf tea for loose stools and for high blood sugar. Traditional use is not proof that a remedy works, and it is not proof that it is safe.
The honest verdict is split. Eating cashews has modest human support for blood fats and blood pressure. The leaf and bark remedies rest on lab and animal work, not on trials in people.
How does marañón work?
Cashew nuts are rich in fat, fibre and plant sterols. In feeding trials, diets built around nuts lower LDL cholesterol (the harmful kind) a little.
The leaf and bark are a different story. In test tubes and in animals, their extracts slow gut enzymes that break down starch. That could blunt a blood sugar spike, but it has not been shown in people.
Lab tests also show leaf extracts can slow the growth of some bacteria. Whether that happens inside the human gut is unknown.
The shell oil is not a medicine. It holds burning compounds from the same chemical family as poison ivy.
What forms does marañón come in?
You will meet marañón as food far more often than as a supplement.
Roasted or steamed nuts, whole, chopped or ground into butter.
Cashew apple juice, pulp, jam and wine.
Cashew milk and cashew-based cheese.
Dried leaf or bark for tea, sold in Latin American markets.
Leaf or bark extract in capsules and tinctures.
Cashew nut shell liquid, sold for industry and not for eating.
Nuts labelled raw in shops have in fact been steamed. Truly unprocessed nuts still carry the burning shell oil.
Where it comes from:
The tree is native to north-east Brazil. Portuguese traders spread it to Africa and India in the 1500s.
Indigenous and rural communities across Brazil, Mexico, Central America and the Caribbean used the plant widely. Healers gave leaf or bark tea for diarrhoea, mouth sores and, later, for sugar in the urine.
The cashew apple was pressed for juice and fermented into drinks. The caustic shell oil was used on warts and corns, a practice that caused burns and is not advised.
These records describe what people did. They do not show that the remedies worked.
If this is an emergency
Some reactions to marañón need urgent care. Call your local emergency number or go to an emergency department straight away — do not wait to see whether it passes.
Who should avoid marañón?
- Do not eat cashews or any cashew product if you have a cashew or tree nut allergy. This ban is absolute.
- Never eat truly raw, unsteamed cashews. The shell oil on them causes burns to the mouth and throat.
- Never swallow cashew nut shell liquid. It is an industrial oil, not a food or a medicine.
- Do not handle cashew shells or shell oil if you react to poison ivy, mango skin or pistachio. These plants are related and can cross-react.
- Do not put shell oil on warts, corns or skin growths, even though tradition did. It causes chemical burns.
- Do not use leaf or bark tea if you are pregnant or breastfeeding. It has not been tested for safety.
- Do not give leaf or bark remedies to babies or young children.
- Do not swap your diabetes medicine for marañón tea. Speak to your doctor before adding any new tea.
- Avoid large daily amounts of cashews if you have had calcium oxalate kidney stones.
- Avoid large amounts if you have advanced kidney disease and have been told to limit potassium.
When should you see a doctor?
Call emergency services at once for signs of a severe allergic reaction after eating cashews. These include swelling of the lips, tongue or throat, trouble breathing, widespread hives, vomiting, or feeling faint.
Get urgent care for blistering, weeping skin after contact with cashew shells or shell oil. Burns from this oil can be deep.
See a doctor if diarrhoea lasts more than two days, or comes with blood, fever or marked weakness.
See your doctor if you have diabetes and your blood sugar readings change after starting any new herbal tea.
4.8
