The B-17 part of the apple seed is not poisen, for there is not free cyinide, for the b-17 molicule is as safe as Sugar or water when still in tact. The only thing in the human body which can break down this molicule is the protein in cancer, then the cynide kills the cancer, joins with other by products of the cancer cell and make glucose. So in either way, it is not poisen. Now that only explains B-17. There are probably other chemicals in the apple seed which would kill in taken in large enough amounts, but too much oxygen can kill you too.