Elephant ear is a broadly used common name for plants in the aroid (Araceae) family with large heart-shaped leaves. Most plants in the genera Alocasia, Colocasia, and Xanthosoma are referred to as elephant ear plants. Elephant ear sap contains asparagine, calcium oxalate, and saponins which are toxic to humans and other mammals[4].
Elephant ears are a popular ornamental plant because of their heart-shaped leaves which can be up to 5 feet long in some species. Taro is one type of elephant ear plant that is grown for its tubers. The tubers can be eaten after being properly cooked.
Elephant ear plants are popular as houseplants and as a food source, it’s important to understand the dangers associated with its sap. In this article, we will cover everything you need to know about elephant ear sap and the risks it poses.
What is Elephant Ear Sap?
Elephant ear sap is a liquid that’s produced by elephant ear plants. Below we describe its appearance, location in the plant, composition, and toxicity.
Appearance And Characteristics
Elephant ear sap is most often a milky white latex-like substance. However, it can also be clear in some species. It is also somewhat sticky in texture.
Which Plant Parts Contain Elephant Ear Sap?
Plant sap is the term used to describe the fluids that transport nutrients and water throughout the plant from the roots to the leaves. Elephant ear sap is present throughout the entire plant. However, its concentration varies in different parts of the plant.
The highest concentration of elephant ear sap is found in the leaf stems. The lowest concentration is in the roots.
Chemical Composition
There are a wide variety of chemical compounds found in elephant ear plants. In this section, we will focus on the toxic chemicals found in elephant ear sap.
Saponin is a toxic chemical produced by plants including elephant ears. Ingesting small amounts may not cause any symptoms.
Larger doses of saponin can result in irritation of the gastrointestinal tract[1]. Large doses can also lead to respiratory failure and dysfunction of the cardiac system[1].
Luckily, elephant ear plants don’t contain very much saponin. Therefore saponin is not usually considered to significantly contribute to elephant ear poisoning.
Elephant ears produce a large amount of insoluble calcium oxalate. Calcium oxalate is the primary toxic component of elephant ears that causes symptoms[4].
Plants produce calcium oxalate that has a needle-like crystalline structure known as raphides. They are primarily responsible for the discomfort caused by touching or ingesting elephant ear sap. The raphides can create microscopic tears in soft tissues leading to irritation.
Asparagine is a protein found in elephant ear sap and plant tissues. Asparagine isn’t toxic to humans. However, the asparagine in plants can form acrylamide when the plant is cooked[6].
Acrylamide is a neurotoxin and has been shown to cause skin irritation. Elephant ear tubers are cooked to dissolve the harmful calcium oxalate crystals. However, this increases acrylamide content which may lead to health issues[5].
Toxicity Level
The University of Kansas Health System gives elephant ear a toxicity rating of 1-2[2].
The terms toxic, toxin, poison, and poisonous are often used interchangeably but have different meanings. Scientifically speaking, a toxin is a poison produced within the cells of an organism. That means not all poisons are toxins but all toxins are poisons.
For example, lead is a poison that can cause adverse effects in many animals. However, lead is a naturally occurring element in the Earth’s crust and isn’t produced by an organism. Therefore lead is not technically classified as a toxin.
To further add to the confusion, even though all plant toxins are technically poisons, toxins aren’t always poisonous. Many toxic plant chemicals must be absorbed, ingested, or inhaled at certain levels before they become poisonous. The amount of exposure to a toxin required to make it poisonous varies by chemical.
Now you’re probably wondering, is elephant ear sap poisonous?
The answer is yes. Elephant ears contain asparagine, calcium oxalate, and saponin toxins in their sap. When consumed by humans, cats, dogs, and horses, these toxins are poisonous[4].
Elephant ear sap toxins can also cause adverse skin and eye reactions on contact[3]. We’ll cover the full range of symptoms caused by elephant ear sap exposure in the next section.
Potential Harm To Humans And Pets
Elephant ear plants and their sap can potentially cause harm to humans and pets. This is especially true if any part of the plant is ingested. Below we provide information about the adverse effects elephant ear sap can cause.
Symptoms Of Exposure To Elephant Ear Sap
There are a variety of symptoms that can result from exposure to elephant ear sap. Symptoms resulting from ingestion include[3,7]:
- Mouth blisters
- Increased salivation and drooling
- Tongue swelling
- Swelling throughout the mouth and throat
- Swelling of the airways[8]
- A burning sensation in the mouth and throat
- Pain associated with swallowing
- Vocal hoarseness
- Nausea
- Vomiting
- Diarrhea
Symptoms caused by skin and eye contact with elephant ear sap include[3,7]:
- Redness
- Pain
- Burning sensation
- Skin rash
- Blindness[1]
If you experience any of these symptoms, contact poison control immediately.
Irritation Levels
The amount of irritation caused by elephant ear sap can vary depending on several factors. Some people are more sensitive to the sap’s toxins and will experience more severe symptoms.
The amount of sap you come in contact with or ingest can also increase the severity of irritation and symptoms. The length of time you are exposed to the sap can also influence the severity of the resulting symptoms.
The route of exposure will also impact the irritation level you experience from elephant ear sap. Skin and eye contact typically results in milder irritation levels than if you ingest the sap.
Allergic Reactions
Some people have reported having an adverse reaction from simply touching elephant ear leaves. This is considered an allergic reaction since many people can touch elephant ear leaves and have no reaction.
If you’re allergic to elephant ear leaves, you may experience an itching or burning sensation on your skin. You may also develop a rash on the area that came into contact with the leaves.
Elephant ear sap rashes that occur after contact are sometimes referred to as an allergic reaction too. They can also be called elephant ear sap burns when they aren’t bumpy like a rash.
Poisoning
Elephant ear sap poisoning is generally caused by ingestion of the plant. The severity of the symptoms is typically dependent on the amount of plant material consumed.
Symptoms of elephant ear sap poisoning can vary greatly from person to person. Some may only experience mild discomfort[2]. Others can experience life-threatening symptoms including breathing and cardiac issues[1,6].
If you think you have been poisoned by elephant ear sap, you should contact poison control immediately and seek professional medical attention.
Treatment For Exposure
If you think you’ve exposed yourself to elephant ear sap, it is best to contact poison control to seek advice. They will advise you about whether or not you should seek professional treatment.
You may also be wondering how to treat elephant ear poisoning on your hands. If you get elephant ear sap on your hands or skin, you should thoroughly wash them immediately[3]. Avoid scrubbing too hard as you wash them to avoid further skin irritation.
If you get elephant ear sap in your eyes, it is best to seek help from a medical professional. While the sap may only cause eye irritation for a few hours, there have been cases where it has caused blindness[7].
If you ingest elephant ear sap, wipe out your mouth. Use a cold, damp cloth to remove any remaining plant material and reduce further irritation[3]. Next, you should immediately contact either poison control or a medical professional to seek advice.
How to Prevent Exposure to Elephant Ear Sap
Elephant ear plants are popular and beautiful ornamental plants. You can reduce your risk of exposure to the sap by using proper protection and handling techniques.
If you have children or pets, make sure elephant ear plants are out of their reach to avoid accidental exposure.
Protective Gear
Wear gardening gloves when touching, pruning, planting, or removing elephant ear plants. They should be thick and made of a material that ensures any sap won’t soak through to your hands.
Protective eyewear will also help prevent sap from accidentally getting into your eyes.
It is also a good idea to wear a long-sleeved shirt and long pants when working with elephant ear plants. This will help protect you from skin exposure.
Handling Techniques
Use caution when handling elephant ear plants. You should handle them gently to avoid causing damage to the leaves or stems. Damage to plant tissues can allow the sap to leak out and increase your chances of exposure.
Always thoroughly wash any gardening tools, clothing, and protective gear to remove the sap. This will help you avoid accidental exposure to the sap.
Frequently Asked Questions
Elephant ear sap is a liquid that typically has a white, milky appearance but can also be clear in some species. It feels somewhat sticky when touched. You should avoid touching elephant ear sap because it can cause adverse skin and eye reactions.
Elephant ear sap is produced in the leaves, stems, and roots of elephant ear plants. It is found throughout the xylem and phloem of the entire plant. These plants will exude their sap whenever their plant cell walls are damaged.
Elephant ear plants can cause some people to feel itchy when they touch the leaves or stems. Other people may also experience a burning sensation after touching elephant ears. Contact with these plants can also cause some people to develop a rash.
References:
[1] Chan, T. Y. K., Chan, L. Y., Tam, L. S., & Critchley, J. A. J. H. (1995). Neurotoxicity following the ingestion of a Chinese medicinal plant, Alocasia macrorrhiza. Human & experimental toxicology, 14(9), 727-728.
[2] Elephant Ear. Poison Control Center. The University of Kansas Health System.
[3] Elephant Ear Poisoning. UF Health. University of Florida Health.
[4] Joshi A, Karnawat BS, Narayan JP, Sharma V. Alocasia macrorrhiza: A Decorative but Dangerous Plant. Int J Sci Stud 2015;3(1):221-223.
[5] Kim, H., Lee, S. G., & Rhie, J. (2017). Dermal and neural toxicity caused by acrylamide exposure in two Korean grouting workers: a case report. Annals of Occupational and Environmental Medicine, 29, 1-6.
[6] Lea, P. J., Sodek, L., Parry, M. A., Shewry, P. R., & Halford, N. G. (2007). Asparagine in plants. Annals of applied biology, 150(1), 1-26.
[7] Lin, T. J., Hung, D. Z., Hu, W. H., Yang, D. Y., Wu, T. C., & Deng, J. F. (1998). Calcium oxalate is the main toxic component in clinical presentations of alocasia mycorrhiza (L) Schott and Endl poisonings. Veterinary and human toxicology, 40(2), 93-95.
[8] Moon, J. M., Lee, B. K., & Chun, B. J. (2011). Toxicities of raw Alocasia odora. Human & experimental toxicology, 30(10), 1720-1723.
