A man in Australia gave himself cyanide poisoning while consuming apricot kernels meant to prevent his prostate cancer from returning.
The 67-year-old apricot kernel extract every day for five years, according to a report in BMJ Case Reports. He took two teaspoons of the extract and three Novodalin tablets, an herbal fruit kernel supplement. That equaled about 17.23 milligrams of apricot kernel extract a day.
The man’s self-prescribed apricot regimen was based on an alternative medicine belief that apricot kernels can prevent or cure cancer. The man was in remission from prostate cancer and was trying to prevent it from returning.
Apricot kernels contain amygdalin, also called laetrile, which is converted into cyanide when it enters the body, then prevents cells from using oxygen, killing them. Those who say apricot kernel extract prevents cancer believe it only affects cancerous cells.
The man was lucky the doctors caught the evidence of cyanide, as he didn’t present with any symptoms — he was at the hospital for a routine procedure relating to his prostate cancer. Because the procedure required anesthesia, the doctors noticed low oxygen saturation and high thiocyanate, a byproduct of cyanide break down in the body.
Doctors told the man to stop ingesting the kernels, and he did — for just three days. Afterwards, he continued to administer the kernels.
Acute cyanide poisoning causes symptoms like headaches, dizziness, shortness of breath, vomiting, seizures, loss of consciousness, cardiac arrest and death, usually within a few minutes. Chronic, long-term exposure, like the Australian patient, can lead to weakness, paralysis, lesions, nerve damage, and may affect liver and kidney function.
The United Kingdom, Canada and the United States all have maximums on either apricot kernel intake of safe levels or cyanide for foodstuffs. Australia, however, banned the sale of apricot kernels as food in late 2015.
Cherry seeds, peach pits and apple seeds can all break down into cyanide in the body but one one would need to eat more than 200 apple seeds, for instance, to receive a fatal dose.