What category of food is a cashew, and why isn't it a nut?

November 10, 2025 •

4 min read

Over 750,000 metric tons of cashews are consumed worldwide each year, yet a surprising number of people misidentify what category of food is a cashew. While a culinary staple alongside other nuts, a cashew is, in fact, a seed of a drupe, revealing a fascinating botanical distinction from true nuts.

Quick Summary

Cashews are technically drupe seeds, not true nuts, but are grouped with tree nuts for culinary purposes due to their similar nutritional profile and usage.

Key Points

Botanical Classification: A cashew is not a true nut but is botanically classified as a drupe seed, similar to almonds and pistachios.
Unique Growth: The edible cashew seed grows inside a kidney-shaped drupe, which hangs from the bottom of the fleshy, pear-shaped cashew apple.
Toxic Shell: The raw cashew shell contains urushiol, a toxic irritant also found in poison ivy, which is why cashews must be heat-processed before they are sold.
Culinary Grouping: Despite its botanical identity, the cashew is commonly grouped with tree nuts for culinary purposes due to similar flavor, texture, and nutritional uses.
Nutritional Powerhouse: Cashews are a rich source of healthy fats, plant-based protein, and essential minerals like copper, magnesium, and zinc.
Versatile Ingredient: The cashew's creamy texture makes it a popular ingredient for a wide range of recipes, including dairy-free milks and cheeses, stir-fries, and baked goods.

The Botanical Classification: Drupe Seeds

Botanically, a true nut is a dry fruit with a hard, woody shell that encloses a single seed and does not split open to release it upon ripening. Examples include chestnuts and hazelnuts. The cashew, however, does not fit this description. The cashew tree, scientifically known as Anacardium occidentale, produces a fascinating and complex fruit structure.

The cashew seed, which is the edible portion, grows inside a kidney-shaped drupe, or stone fruit, that hangs below a fleshy, pear-shaped structure known as the cashew apple. A drupe is defined as a fruit with a fleshy outer layer surrounding a single seed enclosed in a hard shell, like a peach or mango. While the cashew apple is an edible accessory or false fruit, the true fruit is the drupe that contains the cashew seed. This unique growth pattern is the key botanical reason why a cashew is a seed and not a true nut.

The Poisonous Shell and Processing

Another distinguishing factor is the cashew's shell. Unlike many other nuts that can be shelled by hand, the cashew's double shell contains potent toxic substances, including urushiol, the same irritant found in poison ivy. This is why consumers never see cashews in their raw, unshelled form. To make them safe for consumption, cashews must undergo a rigorous heat treatment, typically roasting or steaming, which destroys the toxins and makes the shell safe to remove. This laborious process contributes to their higher market price compared to some other nuts.

The Culinary Classification: A Tree Nut

Despite the botanical truth, the culinary world categorizes cashews as tree nuts. This classification is based on shared nutritional and culinary attributes, and it is a perfectly acceptable and practical way to group them. For cooking, baking, and general consumption, cashews behave much like other tree nuts. They are rich in healthy fats, protein, and minerals, making them a versatile ingredient. This culinary grouping also has important implications for individuals with nut allergies, as cashews can trigger severe allergic reactions similar to other tree nuts.

Comparing Cashews with Other Nuts


Feature	Cashews	Almonds	Walnuts	Peanuts
Botanical Category	Drupe Seed	Drupe Seed	Drupaceous Nut	Legume
Common Culinary Name	Tree Nut	Tree Nut	Tree Nut	Legume / Nut
Texture	Creamy, Buttery	Crunchy, Firm	Dense, Crisp	Crunchy
Primary Fat Type	Monounsaturated	Monounsaturated	Polyunsaturated (Omega-3)	Monounsaturated
Shell Toxicity	Toxic (requires processing)	Non-toxic	Non-toxic	Non-toxic
Nutrient Density	Magnesium, Copper, Zinc	Vitamin E, Calcium	Omega-3s, Antioxidants	Protein, Biotin, Niacin
Common Allergen?	Yes, tree nut allergy	Yes, tree nut allergy	Yes, tree nut allergy	Yes, legume allergy

The Nutritional Benefits of Cashews

Regardless of their classification, cashews offer impressive nutritional benefits that make them a valuable addition to a balanced diet.

Cashews are rich in several essential minerals, with a single one-ounce serving providing a significant portion of the daily recommended intake for copper, which is vital for energy production and brain health. They also contain high amounts of magnesium, important for nerve function and bone health, and zinc, which supports immune function and wound healing.

Moreover, cashews are a good source of heart-healthy monounsaturated and polyunsaturated fats. These fats have been shown to help reduce LDL, or "bad," cholesterol levels. They are also a notable source of plant-based protein and antioxidants like polyphenols and carotenoids, which help fight inflammation.

Versatile Culinary Uses

Due to their creamy texture and mild, sweet flavor, cashews are incredibly versatile in the kitchen.

Ways to use cashews:

Snacking: Enjoyed roasted and salted, or raw (heat-processed) as a simple, satisfying snack.
Nut Butters: Blended into a creamy butter that can be used on toast, in smoothies, or in sauces.
Vegan Alternatives: The buttery texture makes them a perfect base for dairy-free cheeses, milks, and creams.
Stir-Fries and Salads: Add a delightful crunch and richness to Asian-inspired dishes and salads.
Baking and Desserts: Ground into flour for gluten-free baking or used in raw dessert recipes.

Conclusion

While the answer to "what category of food is a cashew" is a nuanced one, the key takeaway is that cashews are botanically drupe seeds but are functionally classified as tree nuts in the culinary world. This duality is what makes the cashew a truly unique and interesting food. Its journey from a toxic-shelled drupe seed dangling beneath a cashew apple to a safe, delicious, and nutritious component of our diet is a remarkable one. Whether you call it a nut or a seed, there is no denying the cashew's valuable place in our kitchens and on our plates.

Understanding the distinct botanical and culinary classifications of the cashew helps to appreciate its unique properties and history. From its rich nutritional profile to its incredible versatility in a wide range of dishes, the cashew is a beloved food for many reasons. The next time you enjoy a handful, you'll know the surprising truth behind this popular snack.

Frequently Asked Questions

A botanical nut is a specific type of dry fruit that contains a single seed and doesn't split open. A culinary nut is a much broader category that includes any edible kernel, seed, or drupe that is used in cooking and baking.

Yes, the cashew apple, the fleshy fruit from which the drupe hangs, is edible. It's juicy, tangy, and rich in vitamin C, but it is highly perishable and therefore rarely exported, often being consumed locally.

Cashews are never sold in the shell because their double shell contains a toxic and caustic resin, urushiol, which can cause severe skin burns and irritation.

A person with a peanut allergy may or may not be allergic to cashews, but cross-reactivity is possible. Peanuts are legumes, while cashews are tree nuts, but it is common for people to be allergic to both.

Yes, cashews are high in fat, but it is primarily heart-healthy monounsaturated and polyunsaturated fats. These healthy fats, along with protein and fiber, contribute to satiety and provide energy.

Cashews are native to northeastern Brazil but are now cultivated in many tropical regions, with major producers including Vietnam, India, and countries in Africa.

Yes, cashews are a common and potent food allergen, often causing severe allergic reactions, including anaphylaxis, especially in young children.