Apple seeds contain cyangenetic glycosides, which release cyanide upon digestion. Many other foods also contain cyanide, such as the pits of cherries, peaches, plums, apricots, and others. It is important to understand that apples, peaches, etc., are safe to eat. It's the seeds (or pits), that we must avoid chewing. As children, many of us have chewed and swallowed apple seeds upon approaching the core. When we chew these seeds, we break open the "seed-coating", which releases the harmful cyanide-containing compounds. Swallowing seeds whole is less harmful, as we cannot fully digest the seed coating, and they pass through the digestive system into the waste. Or do they? Certain bacteria may contribute to digestion of the seed coat. Thus, it is better to be safe, rather than sorry and simply not consume the seeds.
Parents giving a child an apple for the first time can educate their children in these aspects before allowing their child or children to consume these products. If a child is too young to understand, it is recommended that the parent simply, cut the apple into slices, thereby, eliminating the core, seeds, and risk. Additionally, it decreases the probability that the child will accidently choke on a seed. Seeds (or pits) fro peaches, plums, cherries, and other foods can easily lodge between the larynx and throat, proving fatal.