Question

why it is said apple seeds are unhealthy to take in?

Answer 1

Apple seeds contain small amount of cyanide, which is a lethal poison, but you are protected from the toxin by the hard seed coating. If you eat whole apple seeds, they pass through your digestive system relatively untouched. If you chew the seeds thoroughly, you will be exposed to the chemicals inside the seeds, but the dose of toxins in an apple is small enough that your body can easily detoxify it.

Answer 2

Apple seeds contain Amygdalin, that can release cyanide under the right circumstances such as contact with digestive enzymes.Cyanide is a chemical which is a deadliest poison.Many compounds that contain cyanide are found in nature, often in fruit seeds. Amygdalin is one of these.

Apple seeds, as well as many other fruit seeds , 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. Although apple seeds are tough enough to pass through the digestive system intact; no cyanide is released. 

So friends whenever you eat apples never chew the seeds! They are harmful !