18 apples could kill you

Surprising sources of cyanide

A number of edible plants contain low concentrations of hydrogen cyanide in the form of
cyanogenic glycocides.

Butter beans – (Or Lima beans in the US) Have a protective mechanism which releases cyanide when chewed. Wild strains have much higher cyanide (3,000-4,000 mg/kg) but commercial ones must have <200mg cyanide/kg. Boiling for longer reduces cyanide
Black Cherries
Cassava – In Uganda in 2017 involving 98 people were accidentally poisoned and two people died, after eating a cassava flour dish made from wild cultivars of cassava rich in cyanide
Plums
Pears
Bamboo
Bitter almonds – kernels
Nail glue remover – acetonitrile, if swallowed, metabolises to make cyanide in your body
Cigarettes – One filtered cigarette contains 0.1mg cyanide. Unfiltered 0.5mg

How much cyanide would kill you?

Lowest recorded: 0.5mg per kg bodyweight, e.g. 41.8mg for the average UK man who weighs 83.6kg*

Average: 1-1.5mg per kg bodyweight, e.g. 83.6mg (to give you an idea, a paracetamol tablet is 500mg)

12 raw peach stones

20-30 apricot kernels

30+ cherry stones

150+ apple seeds

But don’t let this put you off apples! The human body can process small amounts of hydrogen cyanide and besides, if you don’t chew them, the seeds pass through. Different apple varieties contain different amounts of cyanide. The average apple contains five to eight seeds so you’d need to eat at least 18 apples in a row and thoroughly chew all the seeds to risk cyanide poisoning.