Can apple seeds really kill you?

Have you heard somewhere that apple seeds are poisonous, or even that you could drop dead if you accidentally ate one? Well, these rumors are true in a sense, but it's going to take way more than a single wayward apple seed to finish you off, especially if you don't grind it to a pulp first.

The innocent apple seed, similar to other seeds found in fruits like cherries, peaches, and plums, contains a substance called amygdalin (via Britannica). Once it's metabolized in the digestive system, it changes into something far more heinous called hydrogen cyanide. Pay attention to the second word here — cyanide is super bad for you and if you consume enough, you'll be dead in just a few minutes. 

However, just because amygdalin is found in apple seeds doesn't mean if you ingest one you're going to keel over. For one thing, you have to actually crush or chew the seed in order to access the substance. If you're accidentally swallowing an apple seed, you're likely not going to chew it up in the process. 

Also, and more importantly, even one or two chewed-up apple seeds are not going to murder you. Why? Because it takes oodles of crushed apple seeds to even come close to providing you with enough amygdalin (and cyanide) to kill you off. You'd have to eat anywhere from 150 to several thousand chewed-up apple seeds to succumb to cyanide poisoning. 

So yeah, try to avoid chewing apple seeds because they aren't the tastiest thing to eat, but don't worry if you accidentally swallow one while going to town on an apple core. You cannot digest an intact apple seed, so it will pass harmlessly through your body and exit into the toilet at some point in the future. Also, keep in mind that your body can deal with small amounts of cyanide (even though this sounds like a really weird statement to make), so if for some reason you do chew up a seed or two and they wind up in your stomach, you're not going to die.