Why Shouldn't You Eat the Core of an Apple?

December 12, 2025 •

4 min read

According to the Centers for Disease Control and Prevention, apple seeds and the pits of other stone fruits contain amygdalin, a compound that releases hydrogen cyanide when chewed and digested. While the amount is small, this is the primary reason for avoiding the core, especially the seeds, to minimize potential health risks.

Quick Summary

The primary reason to avoid eating the core of an apple is the small amount of amygdalin in its seeds, which can convert to toxic cyanide when chewed. Swallowing seeds whole is largely harmless due to their protective coating, but it's safest to discard them entirely.

Key Points

Cyanide Risk: Apple seeds contain amygdalin, which releases toxic cyanide when chewed or crushed.
Intact Seeds Are Safe: If swallowed whole, the hard seed coat prevents the release of amygdalin, and the seeds pass through the system harmlessly.
Quantity Matters: A person would need to crush and consume a large quantity of seeds (hundreds) to experience serious health effects.
Core Flesh is Safe: The fibrous part of the core is not toxic and may contain beneficial bacteria, but it is typically discarded due to its unappealing texture.
Safety for Children and Pets: Precautions are especially important for children and pets, who are more susceptible to smaller doses of cyanide due to their body weight.
Not Unique to Apples: Many other related fruits, including apricots, cherries, and peaches, also contain amygdalin in their seeds or pits.

The Science Behind the Seed's Potential Danger

At the heart of the issue is a naturally occurring plant compound called amygdalin, a type of cyanogenic glycoside. Located within the tiny, black seeds of an apple, amygdalin is a defense mechanism for the plant. When an animal or human chews and crushes these seeds, the amygdalin is broken down by the body's digestive enzymes. This metabolic process results in the formation of hydrogen cyanide (HCN), a highly poisonous substance.

How Cyanide Affects the Body

Cyanide works by interfering with the body's ability to use oxygen, specifically at the cellular level. In severe cases of poisoning, this can be fatal. However, it's crucial to understand the context and quantity involved. The hard, protective outer layer of a whole, unchewed apple seed prevents the amygdalin from being released, allowing the seed to pass harmlessly through the digestive system. Only when the seeds are crushed, ground, or thoroughly chewed does the toxic compound become bioavailable. The body can also detoxify very small amounts of cyanide, meaning a single chewed seed is unlikely to cause harm to an adult.

Quantity is Key for Risk Assessment

The amount of amygdalin varies by apple variety and growing conditions. Studies have suggested that an adult would need to consume and crush a significant number of seeds—anywhere from 83 to 500—to experience acute cyanide poisoning. This translates to consuming and chewing the seeds from dozens of apple cores in a single sitting, an unlikely scenario for most people. For children and pets, however, the threshold is lower due to their smaller body weight, and it is always advisable to take precautions.

The Difference Between the Core and the Seeds

It is important to differentiate between the fibrous, fleshy part of the core and the seeds themselves. While the seeds pose the toxic risk, the flesh surrounding them is not harmful. In fact, some modern studies suggest that the core of an apple may contain a significant portion of the fruit's beneficial bacteria, contributing to a healthy gut microbiome. However, the fibrous and woody texture makes it unpleasant to eat for many people, which is another reason it is commonly discarded.

Other Fruits and Cyanogenic Glycosides

Amygdalin isn't exclusive to apples. Many other fruits in the Rosaceae family also contain this compound in their seeds, pits, or kernels.

Cherries: The pits contain amygdalin. Chewing or crushing the pits can release cyanide.
Apricots: The kernels inside the hard pit also contain amygdalin.
Peaches and Nectarines: Like other stone fruits, their pits contain the same compound.

As with apples, the protective outer layer of the pit or kernel prevents the release of cyanide unless it is damaged. Some commercial processes, such as the pasteurization of apple juice, can reduce the amount of amygdalin and cyanide to negligible levels.

Table: Accidental vs. Intentional Apple Seed Consumption


Feature	Accidental Swallowing (Few Seeds)	Intentional Chewing (Many Seeds)
Chewing Action	Minimal or none; seeds remain whole.	Thorough chewing or grinding of seeds occurs.
Amygdalin Release	Negligible; hard seed coat protects the compound.	Substantial; digestive enzymes convert amygdalin to cyanide.
Cyanide Absorption	Minimal to none; seeds pass through undigested.	Possible, and increases with the number of crushed seeds.
Risk Level	Extremely low for healthy adults.	Potential for harm, especially for children or pets.
Recommended Action	No action needed; body can process trace amounts.	Avoid chewing, spit out, and seek advice if large amounts are consumed.

How to Safely Enjoy Your Apple

The easiest and safest way to eat an apple is to simply consume the delicious, nutritious flesh while avoiding the core and seeds. Using a knife to cut the apple into quarters and then slicing out the central core is a common and effective method. For those who enjoy apples in drinks, such as smoothies or juices, it is especially important to core the apple first. Blending whole apples, seeds included, will crush the seeds and release the amygdalin into the mixture. By taking these simple precautions, you can enjoy all the benefits of an apple without any concerns about its seeds.

Conclusion: The Final Word on Apple Cores

The primary reason not to eat the core of an apple is the toxic amygdalin contained within its seeds. While accidentally swallowing a few intact seeds is unlikely to cause harm, chewing or crushing a significant number can be dangerous due to the release of cyanide. The fibrous, fleshy part of the core itself, while unappetizing to some, is not toxic. By simply avoiding the seeds, apple lovers can continue to enjoy this healthy and popular fruit without any cause for concern. For more detailed information on cyanide in food, consult the Agency for Toxic Substances & Disease Registry (ATSDR).

Frequently Asked Questions

Yes, swallowing a whole, unchewed apple seed is not dangerous. Its protective outer coating prevents the amygdalin from being released, and the seed will pass through your digestive system without causing harm.

A toxic dose for an adult typically requires consuming and crushing anywhere from 83 to 500 apple seeds in one sitting, far more than found in a single core. The risk increases with the quantity and how finely the seeds are crushed.

Yes, the apple flesh is safe and healthy for children and pets. However, it is especially important to remove the core and seeds for them, as they are more susceptible to toxic effects due to their smaller size.

Yes, blending crushes the seeds, which releases amygdalin. It is recommended to always core your apples before blending them into smoothies to avoid the potential release of cyanide.

Symptoms of cyanide poisoning, particularly from large, crushed quantities of seeds, can include headaches, dizziness, nausea, and confusion.

The cyanide-producing compound, amygdalin, is not necessarily eliminated by standard cooking temperatures. It's best practice to remove the core and seeds before using apples in cooking or baking.

Yes, pears and other fruits in the same plant family as apples, such as apricots and cherries, also contain amygdalin in their seeds or pits, and it is best to avoid consuming them.