What Chemicals Do Cashews Have? A Comprehensive Overview

December 28, 2025 •

4 min read

Raw cashews contain a toxic substance called urushiol, also found in poison ivy, which must be removed through careful processing before they can be safely consumed. Beyond this initial toxin, cashews are packed with a wide array of other chemical compounds that contribute to both their nutritional value and their unique flavor profile.

Quick Summary

This article examines the diverse chemical makeup of cashews, from their toxic cashew nutshell liquid (CNSL) components like urushiol and anacardic acid to the beneficial compounds found in the edible nut, including healthy fats, antioxidants, and essential minerals. It details the properties and importance of these chemicals and explains why commercial cashews are safe to eat.

Key Points

Toxic Shell Compounds: The shell of the cashew nut contains urushiol and anacardic acid, which are toxic phenolic irritants and must be removed through processing.
Rich in Healthy Fats: Edible cashews contain high levels of heart-healthy monounsaturated fats (like oleic acid) and polyunsaturated fats (like linoleic acid).
Abundant in Minerals: Cashew kernels are an excellent source of essential minerals such as magnesium, copper, zinc, and iron.
Contains Potent Antioxidants: Cashews and their testa (skin) are rich in phenolic compounds and carotenoids like lutein and zeaxanthin that combat oxidative stress.
Vitamins for Vitality: They provide a good amount of various B vitamins and Vitamin K, which support metabolic and bodily functions.
Processed for Safety: All commercial cashews, even those labeled 'raw,' have been heat-treated to destroy harmful chemicals, making them safe for consumption.

Cashew Nut Shell Liquid (CNSL): The Source of Toxic Chemicals

True raw cashews are never sold directly to consumers because their double shell contains a caustic, resinous liquid known as Cashew Nut Shell Liquid (CNSL). The composition of this viscous fluid varies depending on the extraction method, but its most infamous component is urushiol, a powerful skin irritant chemically related to the compound found in poison ivy. Contact with CNSL can cause allergic contact dermatitis, an itchy and inflamed skin rash.

The primary compounds in CNSL include:

Anacardic Acid: A major component of natural, solvent-extracted CNSL (60–65%), this phenolic compound can cause allergic reactions but also possesses a range of biological activities, including antibacterial and antioxidant properties. The presence of an alkyl side chain with varying degrees of unsaturation influences its chemical properties.
Cardanol: The primary component of technical-grade CNSL produced by heat extraction, which removes the carboxylic acid group from anacardic acid through decarboxylation. It is widely used in industrial applications such as resins and coatings.
Cardol and 2-Methylcardol: Other phenolic compounds present in CNSL that contribute to its overall chemical makeup.

The Chemical Composition of the Edible Cashew Kernel

After the toxic shell is removed and the kernels are heat-treated, the edible portion of the cashew remains. This part is a powerhouse of beneficial chemicals, including lipids, proteins, and micronutrients.

Healthy Fatty Acids and Lipids

The fats in cashews are predominantly healthy unsaturated types.

Monounsaturated Fatty Acids (MUFAs): The most abundant fatty acid in cashews is oleic acid, a monounsaturated fat also found in olive oil. It is known for its heart-health benefits, such as helping to maintain healthy cholesterol levels.
Polyunsaturated Fatty Acids (PUFAs): These include linoleic acid, an essential omega-6 fatty acid. PUFAs are important for cell health and are linked to improved cardiovascular health.
Saturated Fats: While cashews do contain some saturated fat, a notable portion is stearic acid, which research suggests may have a neutral or minimal effect on blood cholesterol levels compared to other saturated fats.

Vitamins and Minerals

Cashews are rich in vital minerals that act as cofactors for numerous enzymatic processes in the body.

Magnesium: Cashews contain a high amount of magnesium, a mineral crucial for nerve function, muscle contraction, and bone health.
Copper: This mineral is essential for energy production, brain development, and the maintenance of a strong immune system.
Zinc: A key mineral for vision and immune function.
Iron: Important for the production of hemoglobin, which transports oxygen throughout the body.
B Vitamins: Cashews contain several B vitamins, including thiamin (B1) and Vitamin B6, which are vital for metabolism and brain function.
Vitamin K: A fat-soluble vitamin important for blood clotting and bone health.

Antioxidants and Bioactive Compounds

The kernel and testa (the thin, reddish-brown skin) of cashews contain powerful antioxidants.

Phenolic Compounds: These include catechin, epicatechin, and epigallocatechin. They help neutralize free radicals, reduce inflammation, and protect against oxidative stress. The testa is particularly rich in these compounds.
Phytosterols: Plant sterols with a similar structure to cholesterol that compete for absorption in the intestines, helping to reduce the absorption of dietary cholesterol.
Carotenoids: Antioxidants like lutein and zeaxanthin are present, which are beneficial for eye health.

Comparison of Key Cashew Chemicals


Chemical Compound	Source in Cashew	Primary Function in Humans	Associated Health Impact	Toxic?
Urushiol	Found in the outer shell of the nut	N/A (toxic irritant)	Can cause severe allergic contact dermatitis upon skin contact.	Yes
Anacardic Acid	Primarily in the cashew nutshell liquid (CNSL)	Inhibits certain enzymes; antioxidant, antibacterial.	Potential for allergy, but processed out of edible nut.	Yes, as an irritant
Oleic Acid	Edible kernel	Promotes healthy cell membranes; heart health.	Helps lower 'bad' LDL cholesterol.	No
Magnesium	Edible kernel	Aids nerve and muscle function, bone health.	Essential mineral for overall health.	No
Lutein and Zeaxanthin	Edible kernel, antioxidants	Protects eyes from free radical damage.	Improves and maintains eyesight.	No
Catechin/Epicatechin	Edible kernel, especially the testa	Scavenges free radicals, antimicrobial effects.	Powerful antioxidants that reduce oxidative stress.	No

Conclusion

From the dangerous urushiol and anacardic acid in its shell to the multitude of beneficial fats, vitamins, and minerals within its kernel, the cashew is a fascinating study in chemical duality. Thanks to modern and safe processing methods, consumers can enjoy the rich nutritional profile of cashews without any risk from the toxic compounds present in their natural state. As research continues, the health-promoting properties of cashews' various chemical constituents—especially their antioxidants and healthy fats—are consistently reinforced, affirming their place as a nutritious and valuable food source. For more detailed nutritional information, the USDA FoodData Central provides comprehensive data on the compounds in raw cashews.

Frequently Asked Questions

Cashews are not sold in their shells because the shell contains a toxic phenolic resin called urushiol, which causes a severe, irritating skin rash similar to poison ivy.

The primary toxic chemical is urushiol, an oil found in the shell of the cashew nut. Anacardic acid, another component of the shell liquid, is also a skin irritant.

No, commercial 'raw' cashews are not truly raw. They have been heat-treated, typically by roasting or steaming, to destroy the toxic urushiol in the shell before they are shelled and packaged.

Cashews contain beneficial monounsaturated fats, predominantly oleic acid, and polyunsaturated fats, primarily linoleic acid. These fats are linked to reduced risk of cardiovascular disease.

Cashews contain various antioxidants, including phenolic compounds like catechin and epicatechin, as well as carotenoids like lutein and zeaxanthin, which help protect the body from oxidative damage.

Cashews are processed by first being separated from the cashew apple, then roasted or steamed at high temperatures. This heat treatment breaks down the urushiol before the shells are cracked and the kernels removed.

Besides urushiol, cashews have a moderate oxalate content, which can contribute to kidney stones in high quantities for susceptible individuals. However, the processed nuts are safe when consumed in moderation as part of a balanced diet.