Attention! Be aware of toxic elements in plant-based foods

Published: 10/14/2013 - Updated: 11/23/2016

There are many benefits of consuming vegetables, however, it is important to note that there are some plants that can produce compounds which are toxic to humans. Such compounds can be a natural breakdown product of the plant, while others are generated in response to stress.

Toxic agents in plants often play the role of plant defense, protecting it from environmental assaults, such as pests, herbivores and other threats, however, these substances can be toxic to humans, causing mild to severe reactions.

Some plant foods that can be toxic are:

Apple seeds

Perhaps one of the most popular fruits around the world, the apple provides carbohydrates, polyphenols, antioxidants such as vitamins C and E, fibre, minerals like potassium and amino acids.

However its seeds contain carbohydrates of cyanogenic cyanide group that can produce hydrogen cyanide which is poisonous.

Symptoms of toxicity can occur only if there is an apple seed consumption in excess, i.e. eating an apple seed does not represent a health hazard . Some symptoms which have presented as a result of excessive apple seeds are digestive issues, stomach pain, vomiting, and also may lead to developing respiratory disorders.

Recommendation: Although the doses of apple seeds to cause poisoning is very high, it is recommended not to ingest them as a precautionary measure.

Raw eggplant

Composed mainly of water (up to 92%) eggplants are also a rich source of minerals such as phosphorus, calcium, potassium, magnesium and iron, as well as vitamins A, B1 , B2, B3 and folate.

However, it also contains carbohydrates which have a cyanogenic defense function since they are metabolised by enzymes that produce hydrocyanic acid. So, eating raw eggplant without any preparation, may cause stomach upsets, diarrhea and vomiting due the aforementioned carbohydrates. It is recommend to cook, roast or otherwise prepare aubergine (eggplant) in a cooking process to neutralise its toxicity.

Nutmeg in large quantities

High in fibre, this kind of nut also contains vitamins such as A, C , E and Group B. It also contains sources of phosphorus, iron, manganese, potassium, magnesium and sodium.

Nutmeg contains a substance known as myristicin, a drug that affects the central nervous system and is found in small amounts in the essential oil of the spice. These compounds protect plants against insects.

Low doses of nutmeg are harmless, however a dose greater than 10 grams could lead to hallucinogenic effects that may persist for more than 24 hours.

If regularly consumed in excess, it can cause liver damage, dehydration, nausea, anxiety, generalised pain and even death.

Recommendation: Nutmeg should be used in small amounts, thereby it won’t have any toxic effects.

Green Potatoes

This nutritious tuber, whose main component is water and 18% starch has small amounts of protein, and also a source of calcium, potassium, phosphorus, and magnesium. It also provides vitamins like C, thiamine, niacin and riboflavin.

When green, potatoes contain a toxic compound called solanine, which has a slightly bitter taste which protects it from insects, herbivores and some pests. It also contains another toxic compound called chaconine. These substances can be generated, especially when the potato has been exposed to too much sun.

The main symptoms of green potato poisoning are gastrointestinal or abdominal pain, vomiting, diarrhea and dizziness, which may also occur and typically begins 8-12 hours after consumption.

Recommendation: Cooking can help destroy these toxic substances in part, especially when fried. However, being cooked or boiled in the microwave may not be as effective in destroying toxic compounds, since high temperatures are required. Even so, the main recommendation would be to avoid choosing potatoes that are green, as it is a sign that may have high doses of solanine.

About the author
  • Miriam Reyes

    Miriam Reyes is a professional expert in nutrition and dietetics. She has more than 12 years of experience in caring for patients with overweight and eating problems. She studied at the Universidad del Valle de Atemajac (UNIVA), where she obtained a degree in nutrition. Linkedin profile.