Don't freak out if you accidentally swallow a cherry pit—they're rarely poisonous when eaten whole—but whatever you do, don't eat a broken pit. ... roughly 0.17 grams of lethal cyanide per gram of seed, so depending on the size of the kernel, ingesting just one or two freshly crushed pits can lead to death. read more
Various plant seeds or pits like cherry pits contain amygdalin, which releases cyanide when it is metabolized in your body. The lowest known adult fatal dose of hydrogen cyanide was estimated to be 50 milligrams. read more
In fact, if you eat enough apple seeds or cherry pits, you could die. Apple seeds contain cyanogenic acids. Cherry pits, and seeds from related fruits, including peaches, plums, almonds, pears, and apricots, contain cyanogenic glycosides. read more