The seeds contain amygdalin, a form of cyanide, and you'd have to eat 200 cores at one time to have a problem.
Is it OK to eat apple seeds? The Agency for Toxic Substances & Disease Registry (ATSDR) says that exposure to even small amounts of cyanide can be dangerous. Cyanide can harm the heart and brain, and even lead to coma and death. ATSDR adds that people should avoid eating the seeds of apples, and the pits of fruits that include: peaches.
"The Dr. Oz Show" did an episode in which they talked about the amount of arsenic in children's apple juice. Apple seeds also have a tough protective coating seals the amygdalin inside, unless the seeds are crushed, chewed or otherwise ground up.
It has been evidenced that arsenic in garlic is present in the most toxic inorganic species As(III) and As(V). A non-chromatographic speciation method has been developed for the screening of inorganic toxic species of As in garlic samples by hydride generation atomic fluorescence spectrometry.
What foods have high arsenic? The highest levels of arsenic (in all forms) in foods can be found in seafood, rice, rice cereal (and other rice products), mushrooms, and poultry, although many other foods, including some fruit juices, can also contain arsenic.
Fuck you, bigot, China thinks arsenic is good! How dare you? Take your Christian bigotry and go to Hell! Rapist! How many slave boy you have picking seed apple, Joe?