Food Safety Focus (211st Issue, February 2024) – Article 3

Food Poisoning from Consumption of Wild Taro

In January 2024, a 50-year-old woman developed sore throat and hoarseness after consuming wild taro she collected from a hillside. She was admitted to the hospital for suspected calcium oxalate raphide poisoning and was in stable condition.

Many types of plants contain oxalates. Some, like sodium and potassium oxalate, are soluble in water. Others, like calcium and magnesium oxalate, can form insoluble crystals. The raphides (needle-shaped crystals) are of particular concern as they cannot be destroyed by cooking and can shoot out from the plant cells into its surroundings after being chewed. This can lead to irritation and injuries to the oral cavity.

Locally, food poisoning cases with calcium oxalate raphides mainly involve the consumption of wild taro or other produce that are suspected to be mixed or wrapped with wild taro leaves. To prevent calcium oxalate poisoning, do not pick and eat wild plants and do not use wild taro leaves to cover or wrap produce during transportation and processing.