Cassava, also known as yuca or manioc, is one of the world’s most important root crops. More than 800 million people rely on it as a major source of calories, especially in Africa, Asia, and South America. It grows in poor soils, survives drought, and can be turned into everything from flour to chips to tapioca pearls.

But despite its importance, cassava carries a lesser-known warning: when improperly prepared, it can be dangerous—even toxic.
Understanding why is essential not just for food safety, but for appreciating how remarkable and resilient this crop truly is.

Why Cassava Can Be Potentially Dangerous

1. It Contains Cyanogenic Glycosides—Compounds That Release Cyanide

Cassava naturally contains chemicals called cyanogenic glycosides, primarily linamarin and lotaustralin.
When cassava is chewed, crushed, or not fully processed, these compounds can convert into hydrogen cyanide, a fast-acting toxin.

There are two major categories:

• Sweet cassava

Lower in cyanogenic compounds, generally safer with minimal processing.

• Bitter cassava

Higher in cyanogenic compounds and must undergo proper processing before consumption.

The danger increases during drought conditions because cassava plants produce more of these compounds when under stress.

2. Improper Preparation Can Lead to Cyanide Poisoning

Cassava becomes unsafe mainly when people rush the processing steps or rely on traditional methods that weren’t designed for modern large-scale consumption.

Symptoms of acute cyanide exposure include:

dizziness
nausea
headache
rapid breathing
confusion

In severe cases, it can affect the nervous system, thyroid, or even be fatal.

Chronic low-level exposure—more common in communities relying heavily on improperly processed bitter cassava—can lead to konzo, a neurological disorder causing paralysis of the legs.

3. Cassava Leaves Can Also Be Toxic if Eaten Raw

It’s not only the root; the leaves also contain cyanogenic glycosides.
Although they are rich in protein and vitamins, they should never be eaten raw. Boiling or proper soaking removes most toxins.