Cherries are a beloved summer fruit, but their hard pits often raise questions about safety. Cherry pits, like those of other stone fruits, contain chemical compounds that can be toxic. This potential hazard is tied to a natural defense mechanism within the seed. Understanding the science behind this compound and the circumstances for its release is key to safely enjoying cherries.
The Mechanism of Toxicity
The toxic potential of cherry pits lies in a compound called amygdalin, which is classified as a cyanogenic glycoside. Amygdalin itself is not toxic but is stored within the pit’s kernel as a defense against predators. This chemical is found in the seeds of many plants in the Prunus genus, including cherries, apricots, and peaches.
The danger begins when the pit’s hard shell is broken, typically by chewing or crushing. This damage allows amygdalin to mix with specific enzymes, such as beta-glucosidase, which are also stored within the seed. This enzymatic action then metabolizes the amygdalin, leading to the formation of hydrogen cyanide (HCN). Hydrogen cyanide is a rapid-acting poison that interferes with the body’s ability to use oxygen at the cellular level, which can damage organs like the brain and heart.
Understanding the Toxicity Threshold
Swallowing a whole, intact cherry pit poses minimal risk of cyanide poisoning because the hard outer shell prevents the internal compounds from mixing. The pit is indigestible and typically passes through the digestive tract without releasing the amygdalin. The primary danger only exists when the pit is crushed or chewed, allowing the chemical reaction to occur within the body.
Toxicity is a matter of dose, and the amount of cyanide produced varies widely based on the cherry variety and the person’s body weight. For instance, a small child is significantly more susceptible to cyanide toxicity than an adult. Estimates suggest it could take the ingestion of 3 to 4 crushed Morello cherry pits or 7 to 9 crushed red or black cherry pits to reach a toxic level for a small child. A fatal dose for an adult is estimated to require a much higher number of crushed pits.
The estimated fatal oral dose of hydrogen cyanide for an adult is roughly 50 milligrams, corresponding to ingesting a significant quantity of crushed kernels. Other stone fruits, such as plums and apricots, also contain amygdalin, but the concentration differs between species. Even a few crushed pits can cause serious illness. The highest risk is always associated with seeds that have been ground or extensively damaged.
Recognizing Symptoms and Seeking Help
If a person has chewed and swallowed several cherry pits, monitoring for signs of acute cyanide poisoning is important. Mild symptoms can occur relatively quickly and may include headache, dizziness, nausea, and vomiting. Anxiety or confusion may also be present.
More severe signs of cyanide exposure can manifest as rapid breathing, increased heart rate, difficulty breathing, or seizures. In the most severe cases, symptoms can progress to loss of consciousness, coma, and respiratory failure. If there is any suspicion that a person, particularly a child, has consumed multiple crushed pits and is showing symptoms, immediate medical attention is necessary. Contacting poison control immediately is the recommended first step for guidance.