We learn to distinguish edible chestnuts from matte chestnuts. Because the latter are toxic to humans and can cause serious disorders
Their similarity is undeniable and the origin of all ills. The peel and the shape are very similar, both ripen at the beginning of autumn, and both are enclosed in a hedgehog. But the chestnuts and the fruits of the horse-chestnut tree (which we call "chestnuts matte" or "chestnuts of India") are very different. And, above all, if the former are luscious and also rich in beneficial properties, the others, even if edible for some animals, are toxic to humans.
Yet confusing the two fruits is quite simple, as evidenced by a study by the French Food Safety Agency (Anses): based on data recorded by poison control centers from 2012 to 2018, the confusion between chestnuts and matte chestnuts provoked 11% of all intoxications reported: a percentage second only to those caused by bulb plants exchanged for edible plants.
Indian chestnuts contain saponins, substances that have an irritative effect, which cause vomiting and diarrhea based on the amount that was ingested. These toxins can also cause rupture of red blood cells (haemolysis), but they are little absorbed from the gastrointestinal tract, so it is difficult for this complication to occur after accidental ingestion.
How to distinguish them
And then, we learn to distinguish them from edible chestnuts. Let's start with the capsule that contains them, the Hedgehog. That of chestnuts is brown, has many long spines and contains from two to three fruits at the same time, smaller than the matte chestnuts, a little flattened and almost triangular. The chestnut hedgehog it is green, with small spaced and short spikes, and usually encloses one fruit, larger and more rounded.
Horse chestnuts often found in the city, in parks, in courtyards, along avenues, while chestnut trees grow in woods, forests or orchards. The horse chestnut leaf is formed from different and smaller leaves ovals, which give it a “palmato” appearance, while that of the chestnut is simple and elongated.
The French Food Safety Agency, in case of doubt about the fruits ingested, recommends keeping some or taking a picture of them, to facilitate identification in case of poisoning. If you experience serious digestive problems, which can be a sign of poisoning, call the poison control center or go to the doctor.
Crazy chestnuts should not be eaten, but they are still useful. Their hedgehogs (the seeds) contain theescina, an active ingredient used in herbal medicine ed effective for blood vessels, capillaries and veins: it is a remedy for disorders caused by peripheral venous insufficiency, varicose veins, hemorrhoids, cellulite and capillary fragility. But unfortunately, the belief that keeping a crazy chestnut in your pocket will protect you from the cold has no scientific confirmation.