Sort of - they contain a compound that is broken down into Hydrogen Cyanide, a well known poison especially in old crime novels.

They contain so little of it though and you'd need to chew the seeds well to release it (otherwise the seeds are likely to pass whole through your digestive system), that in practice you'd need to chew vast amounts of apple seeds to have an effect.

Yes, they contain cyanide but it is locked in a harmless form. An example, sodium and chlorine are both poisonous but you eat them everyday locked in the sodium chloride(table salt) form. Some controversial research has shown that the body can actually use this form of cyanide, known as laetrile or b-17, to destroy cancer cells by unlocking the cyanide on them.

I actually read about this recently and was shocked myself I read that even an apple lover couldn't consume enough to hurt them. They say the higher doses are in cherry pits and peaches ect. That is why those pits are so large.

Walnut shells (green) are high enough in the concentration of this alkaloid that you can mash a handful of them and put them in a gunny sack with a rock, then toss the sack in the lake and the cyanide will cause fish to float up to the surface where you can grab them.

Of course, at that point the game warden can grab you!

I would definately NOT juice the whole apple. I know there are people who eat whole apples and that seems to be fine, but a juicer would satisfy this requirement posted by greenhummer "you'd need to chew the seeds well to release it". I am guessing he forgot your question or has never juiced, please, take the seeds/core out, you can juice whole pears and other foods :)

Play it safe, don't juice the apple pits until the jury comes back with a verdict. If you have cancer juice the whole apple because there is some evidence that the apple pits are helpful.