Apple contain plenty of healthful compounds, including antioxidants, vitamins, and dietary fiber.
Apple seeds, however, contain a plant compound called amygdalin, which can have a toxic effect.
Amygdalin is a part of the seeds’ chemical defenses. It is harmless when a seed is intact, but when a seed is chewed or otherwise damaged, the amygdalin degrades into hydrogen cyanide. This is very poisonous and even lethal in high doses.
Amygdalin exists in relatively high amounts in the seeds of fruits in the Rosaceae family, which includes apples, almonds, apricots, peaches, and cherries.
Is eating apple seeds dangerous?
According to Medicalnewstoday, eating a few apple seeds is safe. However, eating or drinking large quantities of ground or crushed seeds could be fatal.
According to a 2015 review, the amygdalin content in 1 gram of apple seeds ranges from 1–4 milligrams (mg), depending on the variety of apple. However, the amount of cyanide derived from the seeds is much lower.
A lethal dose of hydrogen cyanide may be around 50-300 mg.
Apple seeds have the potential to release 0.6 mg of hydrogen cyanide per gram. This means that a person would have to eat 83–500 apple seeds to develop acute cyanide poisoning.
In other words, consuming cups of ground apple seeds might be fatal, or at least cause illness. However, eating the seeds in one apple would not pose a problem.
That said, researchers recommend avoiding eating apple seeds and removing them before juicing apples because of their high amygdalin content.
Other scientists confirm that the amygdalin content in apple seeds can be high and that eating the seeds can be a cause for concern.
Swallowing whole apple seeds is unlikely to cause any symptoms. The seed coating protects it from digestive enzymes, and the seeds can pass through the digestive system undamaged.
Nevertheless, it is probably a good idea to remove the seeds before giving apples to young children or pets.