Apples are a popular and healthy fruit that are a big part of American culture and history. Through resilient genetic diversity, apples are easy to cultivate and tailor to certain tastes. They are also healthy, with antioxidant properties that help protect against cancer-inducing oxidative damage that can lead to various health problems. The saying “an apple a day keeps the doctor away” has withstood the test of time because of the impressive health profile of apples.

But as you bite deep into an apple, reaching its core, you are confronted with something not so sweet: tiny black seeds. Unlike the sweet tang of the fruit, the tiny black seeds found in an apple’s core are another story. They contain amygdalin, a substance that releases cyanide when it comes into contact with human digestive enzymes, but acute toxicity is rare with accidental ingestion of seeds.

How Cyanide Works

Cyanide is a chemical that has gained infamy as one of the deadliest poisons with a long history in chemical warfare and mass suicide. Many compounds that contain cyanide — called cyanoglycosides — are found in nature, often in fruit seeds. Amygdalin is one of these.

Apple seeds, as well as many other fruit seeds or pits, have a strong outer layer that is resistant to digestive juices. But if you chew the seeds, amygdalin could be released in the body and produce cyanide. Small amounts can be detoxified by enzymes in your body, but large amounts can be dangerous.

How Much Cyanide Is Lethal?

According to the Centers for Disease Control and Prevention, 1-2 mg/kg is a fatal oral dose of cyanide for a 154 lbs. (70 kg) man. You would need to finely chew and eat about 200 apple seeds, or about 20 apple cores, to receive a fatal dose.

The Agency for Toxic Substances & Disease Registry says that exposure to even small amounts of cyanide can be dangerous. Exposure to cyanide can harm the heart and brain, and even lead to coma and death. They add that people should avoid eating the seeds of apples, and pits of peaches, apricots, and cherries.

Symptoms of cyanide poisoning can occur rapidly. They can include shortness of breath and seizures, both of which can lead to loss of consciousness.

What About Apple Seed Oil?

Apple seed oil is a byproduct of juice processing, and is made from the raw apple pomace. People use it for its fragrance, as well as to condition hair and calm skin inflammation. Some studies suggest that it’s also a good source of antioxidants and shows some potential as an anti-cancer agent. Another study found apple seed oil to be active against bacteria and yeast. The amount of amygdalin found in apple seed oil is generally very small.

The Takeaway

Apple seeds contain amygdalin, a substance that releases cyanide into the blood stream when chewed and digested. When comparing the amount of cyanide present in apple seeds with the amount needed to induce death, apple seeds in small amounts do not contain enough cyanide to cause harm. However, it is better to spit out seeds to avoid any potential issues.