Chestnut-like nuts found on walking paths and in parks this autumn should not be picked up and eaten. They may be horse chestnuts, which resemble edible chestnuts but contain toxic compounds.
Horse chestnuts cannot be used as a food ingredient, the Ministry of Food and Drug Safety said on the 4th. Their brown, rounded shape closely resembles that of edible chestnuts, raising the risk of confusion on streets and in parks during the autumn.
Horse chestnut trees are commonly planted as street or landscaping trees in urban areas, making them easy to spot along walking paths and in parks. The nuts resemble chestnuts not only on the outside but also when cut in half, making them difficult to tell apart by eye.
An account of nearly mistaking horse chestnuts for edible chestnuts recently drew attention on social media.
One user posted photographs comparing chestnuts with horse chestnuts, warning that picking up chestnuts could land someone in the hospital.
The user wrote that, lacking raw chestnuts for a braised short rib dish, they gathered nuts that looked like chestnuts after noticing a large number of them scattered along a roadside. Checking the photographs afterward, they realized the nuts were horse chestnuts. "People sometimes get confused while picking up chestnut-like nuts along roadsides in the autumn," they said.
The problem is that horse chestnuts contain toxic compounds including aesculin. Eating them can cause vomiting, abdominal pain, diarrhea and dizziness, and in severe cases can lead to breathing difficulties.
The ministry also used its official channels last year to urge the public not to eat brown nuts that appear to be chestnuts, saying they may in fact be toxic horse chestnuts.
The same confusion recurs overseas. A study analyzing data from France's poison control centers found that mix-ups between edible chestnuts and horse chestnuts accounted for 11% of recorded cases of confusion between edible and toxic plants from 2012 to 2018.
The two can be distinguished to some extent by examining the tip of the nut and the shape of the husk. Edible chestnuts have a pointed tip protruding from the end, while horse chestnuts are relatively round and often lack a distinct tip.
The outer husks also differ. Chestnut burrs are densely covered with thin, long spines, while the husks surrounding horse chestnuts have shorter, thicker spines spaced farther apart.
Experts and health authorities stress that the safest course is to avoid eating wild nuts whose origin and species cannot be clearly identified.
