The side effects of chokecherries are a serious concern for anyone harvesting or preparing this native North American fruit. While the ripe berries can be safely consumed when properly processed, the seeds, leaves, stems, and bark of the Prunus virginiana plant contain dangerous cyanogenic glycosides. When these parts are crushed or chewed, they release hydrogen cyanide, a potent and potentially lethal poison.
The Cause of Chokecherry Side Effects: Cyanide Toxicity
The primary concern regarding chokecherry side effects is the risk of cyanide poisoning. This is not from the fruit's fleshy pulp, but from the cyanogenic glycosides found in other parts of the plant. These compounds are present in the seeds (pits), leaves, stems, and bark and serve as a natural defense mechanism against herbivores. The risk is particularly high when leaves are wilted or when pits are crushed, as this releases the toxic substance.
Symptoms of Cyanide Poisoning
Ingesting a significant amount of the toxic parts of the chokecherry can lead to acute cyanide poisoning. The onset of symptoms can be rapid, sometimes within minutes to hours, depending on the dosage.
Symptoms to watch for include:
- Headache and dizziness
- Nausea and vomiting
- Overall weakness and confusion
- Difficulty breathing and shortness of breath
- Rapid heart rate initially, followed by a slow, irregular pulse
- Dilated pupils and agitation
- In severe cases, seizures, convulsions, loss of consciousness, and cardiac arrest
Astringency and Gastrointestinal Upset
Beyond the risk of cyanide poisoning, the chokecherry's raw fruit is known for its intense astringency, which gives it its name. This causes a strong, mouth-drying, and puckering sensation. While not toxic, it can be unpleasant to eat raw. In some individuals, consuming raw berries might lead to mild gastrointestinal upset, such as constipation or diarrhea, although this is more commonly associated with the similar-sounding chokeberry (Aronia).
Safe Handling and Preparation for Edible Chokecherries
To enjoy chokecherries safely, proper handling and preparation are essential. The most common methods involve cooking or drying the berries, which effectively neutralize the toxic compounds.
- Harvesting: Gather fully ripe berries, which are typically dark red or purple in late summer or early fall. Avoid collecting any leaves or stems with the fruit.
- Juice Extraction: For making jellies or syrups, simmer the cleaned chokecherries in water until soft. Use a food mill or strain the mixture through cheesecloth to extract the juice, taking care not to crush the seeds. The seeds contain the toxins and must be discarded.
- Cooking: Boiling the berries, as for making jams, pies, or sauces, is an effective way to destroy the cyanogenic glycosides.
- Drying: Traditional methods, such as sun-drying the berries, also neutralize the toxins. The berries are sometimes pounded and dried to make pemmican.
Chokecherries vs. Chokeberries: A Critical Distinction
It is crucial not to confuse chokecherries (Prunus virginiana) with chokeberries (Aronia melanocarpa). While both are known for their astringent taste, their toxic properties are vastly different. Chokeberries are not toxic and are prized for their high antioxidant content. Misidentification could lead to serious health issues.
Chokecherry vs. Chokeberry Comparison
| Feature | Chokecherry (Prunus virginiana) | Chokeberry (Aronia melanocarpa) |
|---|---|---|
| Plant Type | Small tree or shrub | Shrub |
| Toxic Parts | Seeds, leaves, stems, bark (contain cyanide) | None (entire plant is non-toxic) |
| Edible Parts | Ripe flesh, especially when cooked | All parts, ripe berries are edible |
| Astringency | Intense, mouth-puckering, especially raw | Intense, but not poisonous |
| Flower/Fruit Cluster | Flowers and fruits hang on elongated stems (racemes) | Berries grow in dense clusters |
| Toxicity to Pets/Livestock | Highly toxic, especially wilted leaves | Non-toxic to pets and livestock |
Side Effects in Animals
Chokecherry is highly toxic to many animals, including dogs, cats, horses, cattle, and sheep. The toxic compounds are particularly concentrated in wilted leaves, which can become sweet-tasting to livestock after a frost or when branches are broken. Ingestion can lead to a rapid onset of symptoms and often proves fatal. Signs of poisoning in animals include brick-red mucous membranes, dilated pupils, breathing difficulties, shock, and death. Pet owners with chokecherry plants on their property should take precautions to prevent animals from ingesting any part of the plant, especially the leaves and fallen fruit. For more information on poisonous plants, consult reliable agricultural resources such as the USDA.
Conclusion: Caution is Key
While the sight of a bountiful chokecherry shrub can be enticing, it is vital to remember the potential side effects associated with improper consumption. The cyanide-releasing compounds found in the seeds, leaves, and other plant parts pose a significant health risk to both humans and animals. By carefully identifying the plant, restricting consumption to the ripe fruit flesh, and using proper preparation methods like cooking or drying, you can neutralize the risk and safely enjoy this traditional wild food.
Following strict safety protocols, especially by not crushing the pits and discarding all other plant material, is the best way to prevent dangerous side effects. If any symptoms of poisoning appear after consumption, seek immediate medical or veterinary attention.
