Apricot Stones

Changed on: 30.08.2016

Apricots are a popular type of fruit, but not all parts of the apricot should be eaten: hydrocyanic acid is formed during the digestion of apricot stones. Thus, eating the stones can lead to serious, even fatal, poisonings. Such products should generally not be consumed.

Apricot stones or “Apricot stones bitter” are sold increasingly for direct consumption as a snack in stores and via the internet. Sometimes, they are even endorsed as an inexpensive and effective anti-cancer product. The alleged effect is based on the vitamin B 17 (laetrile or amygdalin) or the poisonous hydrocyanic acid contained in the stone that should kill cancer cells. However, this healing effect has not been confirmed scientifically to date.

Hydrocyanic Acid Causes Poisoning

Chewing and digesting apricot stones forms hydrocyanic acid from the cyanide released by amygdalin. The human body is capable of degrading a certain amount of hydrocyanic acid, but if too much acid is ingested, various poisoning symptoms can appear. The symptoms of an acute poisoning case range from headaches, difficulty in breathing, dizziness and cramps to cyanosis, coma and eventually death. Children need only to ingest small doses to suffer serious poisoning. In addition, older or sick persons are more susceptible to serious poisoning if their own detoxification system does not work adequately anymore.

The acute reference dose (ARfD) is at 75 µg cyanide per kg body weight according to the German Bundesinstitut für Risikobewertung (BfR). This corresponds to 4.5 mg in a person weighing 60 kg. This harmless dose equals about two large, bitter apricot stones per day. Children should not consume these stones at all. 

Diagram: Apricot seeds are enclosed by a woody stone, similar to almonds.

Apricots are a popular type of fruit, but not all parts of the apricot should be eaten: hydrocyanic acid is formed during the digestion of apricot stones. Thus, eating the stones can lead to serious, even fatal, poisonings. Such products should generally not be consumed.

Apricot stones or “Apricot stones bitter” are sold increasingly for direct consumption as a snack in stores and via the internet. Sometimes, they are even endorsed as an inexpensive and effective anti-cancer product. The alleged effect is based on the vitamin B 17 (laetrile or amygdalin) or the poisonous hydrocyanic acid contained in the stone that should kill cancer cells. However, this healing effect has not been confirmed scientifically to date.

Hydrocyanic Acid Causes Poisoning

Chewing and digesting apricot stones forms hydrocyanic acid from the cyanide released by amygdalin. The human body is capable of degrading a certain amount of hydrocyanic acid, but if too much acid is ingested, various poisoning symptoms can appear. The symptoms of an acute poisoning case range from headaches, difficulty in breathing, dizziness and cramps to cyanosis, coma and eventually death. Children need only to ingest small doses to suffer serious poisoning. In addition, older or sick persons are more susceptible to serious poisoning if their own detoxification system does not work adequately anymore.

The acute reference dose (ARfD) is at 75 µg cyanide per kg body weight according to the German Bundesinstitut für Risikobewertung (BfR). This corresponds to 4.5 mg in a person weighing 60 kg. This harmless dose equals about two large, bitter apricot stones per day. Children should not consume these stones at all. 

Diagram: Apricot seeds are enclosed by a woody stone, similar to almonds.

caption
Apricot Stones partially open with a nutcracker / Marillenkerne teilweise geöffnet mit Nussknacker
Marillen

Apricot Stones as Aromatic Substances

Bitter apricot stones and bitter almond stones are traditionally used in marzipan, persipan and related products. However, the hydrocyanic acid content of such products is safely limited by the Regulation on Flavourings. Bitter almonds, which are similar in use to bitter apricot stones, are used in baked goods (e.g. Christmas cakes and bread) as flavouring. The hydrocyanic acid does not present a problem in these baked goods, as it evaporates during the cooking process.

Hydrocyanic Acid is Used by Plants to Fend off Enemies

The so-called vitamin B 17 is not a vitamin like those contained in fruit or vegetables. The actual scientific name for this substance is amygdalin. This substance contains cyanide in bound form and is used by some plants to fend off natural enemies. Amygdalin is found in bitter almonds, stones of citrus fruit, prune stones and apricot stones, for instance. Chewing the raw, peeled stones releases the cyanide from the amygdalin. The more and longer the peeled stones are chewed, the more cyanide is released.

Emergency Contact

In case of poisoning, consult a doctor. If in doubt, consult the poison control centre at the Vienna General Hospital, Wiener AKH -- 01/406 43 43 (around the clock).

Further Information

Statement No. 009/2015 by the BfR of 7th April, 2015: adults should not eat more than a maximum of two bitter apricot stones per day – children should not consume any.

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