Peach pits contain a naturally occurring compound that can convert into cyanide within the body. This compound, amygdalin, is a type of cyanogenic glycoside found in the kernels of various stone fruits. While its presence is a scientific fact, the actual risk to human health depends significantly on the quantity consumed and how the pit is processed.
The Chemical Behind the Concern
The chemical compound in peach pits is amygdalin, a cyanogenic glycoside. Amygdalin itself is not cyanide, but it can release hydrogen cyanide (HCN) when it undergoes a chemical reaction. This reaction is primarily triggered by an enzyme called beta-glucosidase.
When a peach pit is crushed or chewed, this enzyme is released and contacts amygdalin. It catalyzes the breakdown of amygdalin into substances like mandelonitrile, which then decomposes to produce hydrogen cyanide. This biochemical process serves as a natural defense mechanism for the plant, deterring herbivores from consuming its seeds.
Understanding the Risk
Peach pits contain varying concentrations of amygdalin, with some studies reporting levels around 6.8 grams per kilogram of peach kernel. This amygdalin can yield approximately 2.2 milligrams of hydrogen cyanide per gram of the pit’s kernel. While these amounts might seem significant, a single peach pit is unlikely to contain enough of the chemical to cause serious harm to most people.
For an adult, a toxic dose of cyanide would require the consumption and crushing of a substantial number of peach pit kernels. Estimates suggest that ingesting 13 to 15 raw peach pit kernels could lead to a lethal dose for adults. The average fatal dose of ingested cyanide for humans is approximately 1.52 milligrams per kilogram of body weight, with the lowest recorded lethal dose being 0.56 milligrams per kilogram.
Symptoms of cyanide poisoning can manifest rapidly, ranging from mild to severe depending on the dose. Initial signs may include headache, dizziness, rapid heart rate, shortness of breath, and vomiting. In severe cases, individuals might experience seizures, a slow heart rate, low blood pressure, loss of consciousness, and ultimately, respiratory failure or cardiac arrest. Children and pets are more susceptible to cyanide poisoning due to their smaller body mass, meaning a smaller quantity of consumed kernels poses a greater risk to them.
Safe Practices and Precautions
Given the potential for hydrogen cyanide release, it is advisable not to consume peach pits. This is especially important if pits are crushed or chewed, as this action facilitates the enzymatic breakdown of amygdalin. Preventing accidental ingestion is important, particularly for households with young children or pets who are more vulnerable to smaller doses.
Proper disposal of peach pits in sealed containers can help prevent curious individuals or animals from accessing them. The fruit flesh of peaches is entirely safe to eat and does not contain significant amounts of amygdalin. Similar cyanogenic glycosides are present in the seeds of other stone fruits, such as apricots, cherries, and plums, as well as in apple seeds. Therefore, the general advice against consuming the seeds or pits of these fruits also applies.