Cyanide poisoning from apple seeds?

By Joanne Yeo - Tuesday, Oct 30, 2012

Indeed, apple seeds contain cyanide, a potent toxin that interrupts respiration at the cellular level causing several body systems to malfunction. But before you begin on a major boycott of the fruit that has faithfully kept your doctor away, read on to find out what Associate Professor Malcolm Mahadevan, Head and Senior Consultant, Emergency Medicine Department at National University Hospital (NUH) has to say.
He reveals that in fact, cyanide can also be found in the pits of fruits such as cherries, mangoes, apricots as well as bitter almonds. These contain small amounts of cyanohydrins that can release hydrogen cyanide (HCN). If ingested in exceeding amounts, signs and symptoms of cyanide poisoning that can occur include non-specific symptoms like vomiting, headache, anxiety, agitation, confusion, lethargy and in serious cases, seizures and even coma. It can also affect the heart and cause the blood pressure to go very low.
Under such circumstances, it is necessary for the affected person to be admitted to the hospital’s emergency department whereby, depending on the toxicity and duration of ingestion, a decontamination of the gastrointestinal tract or a cyanide antidote kit will be administered.
A/Prof Malcolm also shares that eating a few apple seeds will not kill, as the seeds are tough and generally will pass out undigested. The body is able to deal with small doses of cyanide that may be absorbed. He shares an interesting apple fact: 100 grams of crushed apple seeds can yield about 70 mg of HCN. The lethal ingested dose of cyanide is between 100 to 200mg.
That will mean that around 150 to 300 grams of crushed apple seeds to ingest before fatality kicks in!
Perhaps, a more alarming food containing cyanide that can be harmful if not cooked properly is from the cassava family (e.g. tapioca). A/Prof Malcolm recommends soaking it in water, peeling the skin and boiling it to remove and break down these harmful chemicals to render it safe to eat. Otherwise, cyanide toxicity can result and symptoms outlined earlier will manifest.
We don’t suppose you will ‘accidentally’ eat a mango seed but the next time you accidentally chomp on apple seeds, remember what harm they can bring to you and spit them out el pronto!

These seemingly harmless seeds contain traces of toxic cyanide