The chance of suffering any type of side effect from eating cherries is slim, as long as you’re not allergic. But overconsumption raises some red flags. On the positive side, cherries provide iron, potassium, vitamin C and antioxidant phytochemicals. They’re also good sources of fiber and carbohydrates, so they can boost your energy while adding beneficial fiber to your diet. Cherries contain enough fiber and carbs to cause problems if you eat too many, however.
Note about Allergies
Cherries contain proteins that cause allergies in some people. If you’re allergic to cherries, you can’t eat any amount without suffering a reaction, which may include shortness of breath, swallowing problems, hives, nausea or diarrhea. Consuming either a few cherries or a large amount can result in life-threatening symptoms such as difficulty breathing and low blood pressure. People who are allergic to grapes, apples, peaches, apricots or hazelnuts may also have an allergy to cherries, reports the American Academy of Allergy, Asthma and Immunology.
Don’t freak out if you accidentally swallow a cherry pit they’re rarely poisonous when eaten whole but don’t eat a broken pit. Because aside from tasting really bitter and generally being impossible to chew, the stones of certain stone fruits, like cherries, contain cyanogenic compounds science talk for “stuff that your body can turn into cyanide.”
Hydrogen cyanide is lethal at about 1.52 milligrams per kilogram, meaning that it takes little more than 0.1 grams of the toxin to dispatch a 150-pound human. A single cherry yields 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.