What is a cashew?
The cashew is one of the strangest commercially traded foods on earth — a tree-fruit-and-seed combination, native to Brazil, that travelled the world on Portuguese ships and ended up powering a billion-dollar global trade. Here's how the cashew actually works, botanically and commercially.
Botanically: the kernel is a seed, the "nut" is a drupe, the apple is a pseudofruit. Anacardium occidentale, family Anacardiaceae — same family as mango and pistachio.
Scientific name
Anacardium occidentale
Family Anacardiaceae — same family as mango and pistachio
Origin
Northeastern Brazil (Ceará, Piauí)
Spread by Portuguese explorers from 1500s
Growth
Evergreen tree, 6–14 m tall
Productive at 3–5 years; lifespan 30+ years
The strange anatomy
The cashew "nut" is not a nut in the botanical sense. It's a seed contained inside a hard, double-shelled drupe — and the drupe hangs from the bottom of a fleshy, swollen pseudofruit (also called the cashew apple). So the structure, from top to bottom, is:
- Cashew apple (the fleshy "fruit") — yellow, orange, or red when ripe. Highly perishable. Tart-sweet flavour.
- Drupe — the hard, kidney-shaped shell hanging below the apple.
- CNSL layer — between the outer and inner shells. A caustic phenolic resin (cashew nut shell liquid) containing anacardic acid and cardanol. Skin contact causes burns; ingestion is toxic before processing.
- Kernel — the actual edible seed inside, in its iconic kidney shape.
Why processing is hard
The CNSL is the reason raw cashews are never sold to consumers. Steaming or roasting the drupe converts the harmful phenolics into harmless residues, after which the shell can be cracked and the kernel extracted. The process is labour-intensive and historically dangerous for processing workers — protective equipment and modern automation are an active sustainability issue in the industry. CNSL itself is recoverable as a valuable industrial by-product (used in brake linings, paints, coatings, and electronics).
The cashew apple
Outside Brazil, India, and a few other markets, the cashew apple is almost never traded — it's too perishable and bruises easily, and the seed (the kernel) is the commercially valuable part. In Brazil it's used for juice (cajuína), sweets, and the artisan distillate cajuína. In Goa, India, it's fermented and distilled into feni — a heritage spirit with Geographical Indication status. The cashew apple is one of the most undermonetized parts of the cashew supply chain globally.
From Brazil to the world
The cashew tree was endemic to coastal northeastern Brazil. Portuguese explorers arriving in the early 1500s carried seeds and seedlings on their trade routes — to East Africa (Mozambique, Tanzania) and Goa (India) starting in the 1560s. From those colonial seeding points, the tree spread across the tropical belt: West Africa, the Western Ghats, Vietnam, the Philippines, parts of the Caribbean. Today over 60 countries grow it commercially, but Ivory Coast, India, Vietnam, Tanzania, and Mozambique dominate global trade.
Nutrition snapshot
Per 100g of plain cashew kernel:
- Energy: ~553 kcal
- Protein: 18g
- Fat: 44g (66% monounsaturated, 18% polyunsaturated)
- Carbohydrates: 30g (3g fibre)
- Magnesium: 292 mg (78% DV)
- Copper: 2.2 mg (244% DV)
- Zinc: 5.8 mg (53% DV)
- Vitamin K: 34 µg (28% DV)
A standard serving (≈28g, about 18 kernels) is roughly 155 kcal, 5g protein, and 12g fat — making cashews a moderate-density nut. Most modern dietary guidance suggests 28–30g of mixed nuts daily as a heart-healthy inclusion, with cashews being lower in saturated fat than coconut or macadamia.