Among most people in the U.S., cassava could be called a fairly unfamiliar vegetable, but it’s viewed as an important staple in diets of millions of people around the world. Visually similar to sweet potatoes, this root vegetable has its own unique and beneficial set of nutrients, and several other advantages, as well, not always for food.
From a shrub with the botanical name Manihot esculenta, cassava is also known as yuca root (but not the same as yucca), or manioc. Apart from being a major food source, cassava has proven itself to be quite versatile.
As the Encyclopedia of Food Sciences and Nutrition1 notes, cassava roots are either “sweet,” containing less than 50 milligrams (mg) of potential hydrogen cyanide per kilogram (km), or “bitter,” with at least 250 mg of hydrogen cyanide per km of fresh root.
The sweet and bitter aspects are both significant, as the sweet variety is used for food, while the bitter type is used in industrial applications. Either way, the cyanide content, which is significant, is lowered during cooking or processing. This is important, especially when it comes to its use as a food (as I’ll discuss later).
Some claim that cassava originated in Portugal, with its earliest cultivation in Portugal and subsequent transport to Central Africa and eventual arrival in Asia and the South Pacific.2 According to Softschools3, Nigeria is the most prominent manufacturer of cassava, while Thailand is the leading exporter of cassava worldwide.4
Easy to grow in areas warm enough to avoid frost, cassava roots consist of four to eight individual tubers at the base of the stem, each around 12 inches long and roughly 2 or 3 inches wide. It’s propagated via stem cuttings. Beginning with the nutritional aspects and adding others, here are five of the top benefits of cassava.
1. Cassava has a wide array of nutrients — The content of the root itself is essentially pure carbohydrates, and in fact may be the highest-calorie tuber known, but it does have its benefits, especially in areas of the world where calories are at a premium. Another way to put it is that it has a wide variety of nutrients, but not a lot of any one thing.
The root may not have a lot of protein as vegetables go, but it has more than most cereals and pulses, with 2.5 percent of the DRI (dietary reference intake) in the same one-half-cup serving, and more protein than that of other tropical food sources, such as plantains, white potatoes or yams.
One cup of boiled cassava5 contains 330 calories, 78 grams of carbohydrates, 3 grams of protein and 4 grams each of fiber and sugar. You’ll also find B-complex vitamins contained in cassava including folate, thiamin, B2, B5 and B6, as well as iron, zinc, calcium, magnesium, potassium and manganese.
According to MedicalNewsToday,6 cassava is a source of resistant starch, which scientists say resistant starch may boost a person’s gut health by helping nurture beneficial gut bacteria. Resistant starch is beneficial because it feeds the friendly bacteria in your colon and turns them into important short-chain fatty acids.
It also improves your gut bacteria and, as a bonus, may lower your blood glucose levels. Resistant starches remain relatively unchanged as they pass through your digestive tract.
Another beneficial aspect of eating cassava is its fiber, which is broken down into short-chain fats to both balance and enhance your gut bacteria.7 Cassava also contains saponins to help lower inflammation.
2. Cassava: A crop that can feed the world — Cassava is one of the ancient foods that sustained generations of people who lived along the banks of the Amazon River in South America. In fact, not just the roots but the leaves of the cassava plant were consumed long before Columbus ever arrived.
Not much has changed; cassava is still recognized as an important food source for millions, as people in around 80 countries, from Nigeria to Cameroon to Togo, reportedly rely on cassava as a vital food source, which translates to bolstering the diets of about 800 million people, a 2012 study notes.8
In addition, it’s known as one of the most drought-resistant crops in the world,9 without much need for fertilizer.
3. Cassava is useful for manufacturing and livestock purposes — Cassava is used to feed animals on a gigantic scale, primarily in South America, the Caribbean and Europe. Its leaves are harvested when the plant is still young and sun-dried for a few days, then the hay is used to feed cows, buffalo, goats and sheep.10
“A Feasibility and Market for Cassava Industrialization in Uganda,” published in 2017, notes that cassava is also used to make fabrics, paper and building materials, including plywood, as well as for the production of ethanol for use as biofuel,11 with China and Brazil the most prominent manufacturers of cassava-based biofuel.
4. Cassava is extremely versatile — Published in 1988, a comprehensive book called “Cassava in Food, Feed and Industry”12 lists a number of different drinks and fermented foods that cassava is used in after being peeled, soaked, cubed, grated or “riced.” Cassava may also be roasted, boiled, steamed into a paste, dried, baked and crumbled.
Cassava is often mixed with other foods such as coconut and bananas to change its texture and flavor. As a carbohydrate, cassava can be mashed, made into chips or french fries, and used in dishes both sweet and savory, like the latter for a Cuban dish known as yuca con mojo, combining cassava with citrus juices, garlic, onion, cilantro, cumin and oregano.
5. Cassava is gluten-free — This means it doesn’t contain the protein gluten, like wheat, that can cause potentially serious adverse reactions. What does “gluten-free” mean in terms of food manufacturing?
In 2013, the U.S. Food and Drug Administration (FDA) issued a new definition for “gluten-free” for the purpose of food labeling, which stated a food must contain no more than 20 parts per million (ppm) of gluten to be labeled as gluten-free.13 As Medical News Today explains:
“An ingredient that has been derived from a gluten-containing grain can be labeled as ‘gluten-free’ if it has been processed to remove gluten and use of that ingredient results in the presence of less than 20 ppm of gluten in the food.”14
However, some foods are gluten-free naturally, and cassava is one of them. Interestingly, some are labeled “gluten-free” when it’s clear that cassava doesn’t contain gluten — and couldn’t.
Caveat Concerning Cassava Consumption: Don’t Eat It Raw
There’s a really big caveat to eating cassava: Avoid eating it raw, because it’s toxic in this form. One study15 notes that as a root crop, it accumulates two cyanogenic glucosides: linamarin and lotaustralin. It’s the linamarin, found in all parts of the cassava plant but primarily concentrated in the root and leaves, that produces the toxic compound hydrogen cyanide (HCN). As Mother Nature Network observes:
“When properly soaked and dried, and especially when people have protein in their diet, bitter cassava is OK; but when any of the process is skimped on, problems arise. Due to correct food processing and strict regulations, cyanide-laced cassava poses little threat to Americans who eat the root.
But, in Africa, where cassava has become a major part of subsistence diets, many poor people suffer from a chronic and crippling form of cyanide poisoning known as konzo.”16
Only soaking the cassava roots and leaves and cooking them at high temperature render the toxic compounds harmless. Otherwise, side effects can be serious and range from intoxication and extreme pain to nausea and death.17 Along with dangerously decreased levels of iodine comes an increased risk of developing goiter, a thyroid condition, all due to cyanide poisoning.18
If they happen to ingest raw cassava, children can experience irreversible paralysis in their legs, and the elderly can develop a condition known as tropical ataxic neuropathy (TAN), resulting in a loss or distortion of sensation in the hands and feet, weakness, poor vision and difficulty walking.19
How Tapioca Is Made
Tapioca is the starchy liquid extracted from the cassava root to make tapioca flour, the base for a uniquely sweet, delicious dessert in the form of pudding, and often used as a thickening agent.20 In comparing cassava root with tapioca, one cup of dry pearl tapioca contains 544 calories, 135 grams of carbohydrates and 5 grams of sugar.21
In most parts of the world, harvesting cassava roots is a manual process. About 70 percent of each root is water and 24 percent is starch, with 3 percent being fats, minerals and sugars, 2 percent fiber and 1 percent protein.22 Because they begin to degrade within 24 hours of being harvested, timely and thorough processing is recommended.
According to a book written in 2003, “The Encyclopedia of Food Sciences and Nutrition,” It’s a tedious process: First, dirt and debris are washed away from the roots, and then the tough skin peeled off.
To break the cell walls, roots are chopped into small chunks to feed into what is called a rasp disintegrator to dispose of the hydrogen cyanide, and the remaining pulp washed on screens to strain out the starches and retain the fiber, which is usually used either as fertilizer or cattle feed. The book adds:
“The starch slurry (also called starch milk), after screening, is put through a continuous centrifuge to separate the starch from fine fiber and soluble material. This can also be achieved by sedimentation.
Starch thus collected may be reslurried and put through a centrifugal purification process as desired. Typically, sulfur dioxide (0.05 percent) is added to water used in the centrifugation purification processes to prevent microbial growth.
Starch slurry from the purification process is dewatered by centrifugation or vacuum filtration and then dried by drum, belt, tunnel or flash methods. Flash-drying is most common. The final moisture content of the dried starch is in the range of 12 to 14 percent. Dried starch aggregates are pulverized to obtain a free-flowing powder.”23
Additionally, tapioca starch is sold in several forms, depending on what it will be used for, and the texture depends on such factors as the plant variety, where it was grown, its age, the amount of rainfall, fertility of the soil and the manufacturing processes implemented.
Clearly, cassava has made its mark on the world and continues to do so. In the future, cassava may have important potential for use in food and manufacturing processes worldwide. According to Medical News Today:
“Scientists may eventually be able to replace high-fructose corn syrup with cassava starch. Researchers are also hoping that cassava could be a source of the alcohol that manufacturers use to make polystyrene, PVC and other industrial products.”24