Natural Born Killers: 7 Fruits and Veggies That Could Be Considered Poisonous

What do ackee, cassava, cycad, lychee, potatoes, red kidney beans, starfruit, and sugar cane have in common? While that question may sound like the opening line of an offbeat joke, the health-related similarity these fruits and vegetables share is no laughing matter.

Plants, like animals, employ various strategies to ensure their survival, and naturally occurring toxins help some plants resist disease and insects.

While you may think everything in nature is suitable for human consumption, each one of the fruits and vegetables mentioned above contains small amounts of toxins that may harm your health when ingested at certain times or in large amounts.

As reported by CNN, there are important considerations you must keep in mind should any of these “natural-born killers” appear on your grocery list.

Ackee: Jamaica’s National Fruit Must Be Cooked Before Eaten

In Jamaica and West Africa, where the ackee fruit is grown, the toxic risks of the plant are well understood.

Similar to starfruit, unripe and unopened ackee contains a poison known as hypoglycin, which, according to Medscape, can lead to potentially fatal toxicity known as “Jamaican vomiting sickness.”

Nonetheless, ackee endures as the national fruit of Jamaica, even taking its place alongside saltfish as part of the country’s national meal.

Given its mild flavor and buttery, creamy texture, ackee is usually treated as a vegetable in cooking, as opposed to fruit. It is used in many savory dishes because it pairs well with other vegetables, meat, and fish.

To ensure the elimination of potentially harmful toxins, ackee is most often boiled, and always must be cooked before it can be eaten. Most natives know what to do in cases where unripe ackee is ingested, says Peter Spencer, Ph.D., professor of neurology at Oregon Health and Science University School of Medicine:

“It’s well-known in Jamaica if your child eats an unopened or unripe ackee fruit, you better get ready to take them to the hospital or give a spoon of sugar to increase glucose.”

An outbreak of epidemic fatal encephalopathy that killed 29 school-aged children in Burkina Faso, West Africa, was linked to ackee poisoning. Due to its potentially lethal nature, authors of a 2004 study published in Food and Chemical Toxicology, validate Spencer’s suggestion to administer sugar quickly. They said:

“[C]onsidering the high lethality of ackee intoxication, the total absence of any existing treatment and the safety of glucose administration, we recommend at this stage to use early sugar or glucose administration in the field, in addition to a specific population-based prevention program.”

Cassava Root Naturally Contains Cyanide

According to CNN, cassava, also known as yucca, follows closely behind corn and rice as the most important calorie source in Africa, South America and parts of Asia. Some 600 to 800 million people worldwide are believed to consume cassava daily.

Cassava is most commonly baked, boiled or fried, releasing a gummy, starchy texture. It can also be ground into flour.

Organic cassava is a primary ingredient in my cocoa-cassava gourmet snack bars, one of my favorite occasional treats. Processed under rigorous health and safety standards, the organic cassava used in my snack bars adds a hint of sweetness and moisture, as well as calcium.

Regardless of its preparation method, cassava must be processed properly; otherwise, it is poisonous. “It feeds millions across the world,” Spencer notes. “But if you’re very poor and don’t have time to process it, then you come down with a disease.”

Of the two main types of cassava — sweet and bitter — bitter contains the most concentration of a cyanide-inducing compound called cyanogenic glycosides, more than 50 milligrams per kilogram. Hydrogen cyanide is released from the cyanogenic glycosides through chewing when it is mixed with enzymes, resulting in the release of hydrogen cyanide.

Whereas the sweet variety only requires boiling to reduce its potential cyanide content to non-toxic levels, the bitter root contains more toxins and therefore requires both soaking and cooking prior to consumption.

Signs of cyanide poisoning include convulsions, diarrhea, mental confusion, stomach pain, twitching, and vomiting. According to the U.S. National Institutes of Health, cassava’s toxins can also cause sudden, irreversible paralysis, commonly known as “konzo.”

Konzo most often affects people living in developing regions affected by armed conflict, drought or famine, who may be at risk of eating cassava unprocessed. According to the authors of a 2011 study published in PLOS — Neglected Tropical Diseases:

“Increasing cassava production, declining production of other foods, global warming, more frequent droughts, wars and population displacement have set the scene for konzo to persist …

Immediate interventions to prevent konzo in affected areas, such as … the wetting method to detoxify cassava flour in some affected areas, are essential.”

Says Dr. Desire Tshala-Katumbay, a staff scientist at the Oregon Institute of Occupational Health Sciences:

“There is more attention [being given] to the problem and more research is being done. I hope in time we will get enough expertise to … think about interventions to protect children from brain damage related to malnutrition and cassava toxicity.”

Cycad Toxins Must Be Removed Before Any Part May Be Eaten Safely

Cycad sago is a starch extracted from the stems of ancient, highly toxic palm-like plants that grow in tropical regions around the world. Sago is used for both food and medicine but, like cassava, requires extensive processing to be safe for human consumption.

Lychee Toxins Can Lead to Fever, Convulsions, and Seizures

Despite its spiky exterior, when enjoyed at its peak, lychee fruit can be smooth, juicy and beautifully sweet. Unfortunately, this tasty exotic fruit, also known as litchi, can be toxic and sometimes fatal when eaten before it is ripe. Malnourished children are at particularly high risk for serious illness and death from lychee poisoning.

Potatoes Can Be Poisonous When Sprouted or Green in Color

Red Kidney Beans Should Not Be Eaten Raw

Awareness Is Your First Line of Defense

The best way to avoid ingesting plant toxins is to be aware of what you are eating and informed about any potential toxins in your food. This article touched on a handful of fruits and vegetables — clearly, there are countless other food items that may be of concern to you personally. It’s worth your time and your health to become educated.