#1 Almonds

A natural source of cyanide! All of the ingredients are present but not activated until the seed (the almond we know and love) is injured – i.e. crushed by teeth. But again, nothing to worry about – domesticated almonds do not contain this natural defense mechanics.

#2 Tomatoes

Tomatoes (the fruit) are non-toxic, but atropine is present in the stems and leaves. While only one death seems to have been attributed to atropine poisoning, ingestion can cause dizziness, headaches and indigestion. Advice? Avoid tomato-leaf tea.

#3 Stony Fruit

Cherries, Apricots, Peaches & Plums The pits (or stones) of these stone fruits also contain cyanide. Swallowing a whole pit or two won’t do a lot of damage, but much like almonds, the toxin becomes exposed when the seed is crushed or damaged – or chewed upon, making children and pets particularly vulnerable. Every year, a handful of deaths (in children and adults) are attributed to an over-indulgence in fruit pits – yikes!

#4 Potatoes

Potatoes naturally contain solanine. Solanine has natural fungicidal and pesticidal properties (an obvious natural defense) and, in potatoes, develops when exposed to light – another reason to store your spuds in a cool, dark place.

Once they begin sprouting or green patches appear, you may want to think twice before eating. Even after cooking, solanine is fairly potent and can cause nausea, indigestion, diarrhea, and vomiting, as well as cardiac problems and dizziness. Hallucinations, paralysis, fever, hypothermia and death have also been reported as symptoms of more severe cases.

#5 Apples

Apples Like stone fruits, apple seeds contain that pesky compound – cyanogenic glycosides – which, through an enzymatic process, turns into cyanide. While the seeds of an apple or two won’t cause you any harm, there have been known deaths as a result of over-eating. While those seeds may not grow into trees in your digestive tract, they may cause a few less far-fetched health problems.

#6 Cassava Root

Cassava/Manioc Root A South American native (also known as Yuca), cassava root is a starchy tuber and the third most-consumed food in the world. While both the sweet and bitter varieties contain cyanide, the latter contains higher levels which makes it naturally pest-repellent and thus, the preferred crop. Soaking the root in water can help kick start an enzymatic process that will liberate the cyanide, but the subsequent liquid becomes toxic as a result. Unprocessed, a pound of bitter yuca can kill a cow – and certainly a person.