Cassava is a vital root crop, consumed by about 500 million people. It’s no wonder that people often ask if it’s safe for pregnant women.
Cassava starch can be safe during pregnancy in small amounts. Cassava root, leaves, flour, chips, cake, and other products may not be. Cassava contains cyanide that is retained, even after cooking.
Are all cassava products unsafe? Is there a way to make them safer during pregnancy? What serving size am I allowed? Answers to these questions and more are below!
Is It Safe to Eat Cassava Root During Pregnancy?
Cassava root is not safe for consumption during pregnancy when consumed in large amounts regularly and over a long period of time.
Cassava, also called Manioc, Yuca, or Tapioca with the scientific name Manihot esculenta Crantz, is an important economic global crop. In fact, it is the most essential cyanogenic food for human beings.
Cyanogenic food sounds off, I know. But, let’s learn more!
All parts of the cassava plant (Manihot esculenta Crantz) are significantly high in cyanogenic glycosides (linamarin, lotaustralin, and amygdalin), which creates hydrogen cyanide. The roots contain the least amount of cyanide compared to the leaves and stem.
Cassava (Manihot esculenta Crantz) has two types: sweet and bitter. The sweet variety produces less cyanide at 20 mg per 1 kg of root, while the bitter variety produces up to 1 g per 1 kg of root.
Dietary consumption leading to toxicity from long-term cyanogenic glycosides can cause many adverse effects such as goiter, cretinism, tropical ataxic neuropathy, growth retardation, and cyanide poisoning (source: Gavin Publishers).
Some of the symptoms of cyanide poisoning are headache, dizziness, abdominal pain, confusion, shortness of breath, and vomiting, with the most severe effects being seizures and coma (source: eMedicineHealth).
Preparing and cooking cassava (Manihot esculenta Crantz) can reduce the cyanide levels considerably, but not totally. Sweet cassava requires less processing compared to bitter cassava which involves peeling, grating/cutting into small pieces, soaking, sun-drying, and cooking (source: Centre for Food Safety).
Boiled cassava (Manihot esculenta Crantz) has a little over 50% of its cyanogen glycosides retained which is at 77.6 mg HCN/kg.
This is why, to be on the safe side, pregnant women should only eat fully cooked cassava, and in moderation.
Can Cassava Cause Birth Defects?
In a study conducted on pregnant hamsters, one group was fed both sweet and bitter cassava meals compared to a controlled group that was fed a meal similar to the nutritional composition of cassava but without the cyanogenic glycosides.
Results showed that fetuses from dams fed with cassava had toxicity, were smaller than usual, weighed less, and had decreased bone ossification (source: Oxford Academic).
In another study on albino rats, the pregnant albino rats were fed with milled cassava powder during the first 15 days of pregnancy. Results showed that there was a low incidence of birth defects such as open eye, microcephaly, limb defects, and growth retardation (source: Wiley Online Library).
These are animal studies, rather than human studies, but their results suggest that consuming large amounts of cassava (Manihot esculenta Crantz) during pregnancy may be unsafe.
Is Cassava Starch or Cassava Flour Safe When Pregnant?
Cassava starch is safe during pregnancy, while cassava flour has conflicting studies and should probably be avoided during pregnancy.
Because cassava starch undergoes several processing stages, total cyanogen removal takes place (source: Gavin Publishers). The liquid is filtered, decanted, and then sun-dried or oven drying at 95 °F–104 °F (35 °C –40 °C) for 12 h (source: NIH).
The World Health Organization has established the cyanogen limit for cassava flour at 10 ppm or 10 mg HCN/kg (source: Gavin Publishers).
In Angibya, Nigeria, cassava flour has been found to have the highest amounts of hydrogen cyanide (source: ScienceDirect). In 2019, cyanide poisoning broke out in western Uganda due to the consumption of cassava flour (source: CDC).
However, cassava flour has also been shown to contain some of the lowest cyanide when processed through soaking, crushing, and sun-drying (source: Gavin Publishers).
Cassava starch and flour are widely used in bakery goods and desserts. Some of the most popular products are tapioca and cassava cake.
Tapioca, found in Boba in the form of black pearls, can be safe. This is because it has undergone several handling and cooking procedures, which, according to the above data, can considerably reduce the cyanide levels.
The serving size of black pearls in Boba is also small. For cassava cake, more research is needed regarding its safety and serving limits.
What is known is that steaming, baking, and frying are best suited for sweet cassava (source: Gavin Publishers).
Can I Eat Cassava Chips When Pregnant?
In Kenya, cassava chips were discovered to contain Staphylococcus spp., as well as coliforms due to improper and unhygienic practices (source: African Crop Science Journal). This doesn’t automatically mean that all chips are unsafe, but that you have to be very careful about where you source the cassava chips from.
In Australia, 10 years after the implementation of the 10 ppm cyanide limit for cassava products, it was found that cassava products in Melbourne still contained high amounts of cyanide. The highest was cassava chips at 48.4 ppm.
This recent study also noted that imported cassava products had higher cyanide values than those made in Australia.
While cooking considerably decreases cyanide levels in cassava root products as in chips, it doesn’t completely eliminate them (source: Foods).
In conclusion, it’s probably best to either limit or avoid eating cassava chips when you’re pregnant. If you do choose to eat them in moderation, then ensure they are from a high-quality, reputable manufacturer.
Are Cassava Leaves Safe During Pregnancy?
Compared to the roots, the leaves of the cassava plant (Manihot esculenta Crantz) were reported to contain the most cyanide at 53-1300 cyanide equivalents/kg of dry matter (source: Gavin Publishers).
Therefore cassava leaves could be unsafe during pregnancy due to their high cyanide content.
Cassava leaves are studied to potentially contain protein, as well as vitamins and minerals, and could meet the global protein requirement, especially for malnutrition. However, like the root, they contain anti-nutrients and cyanogenic glucosides and may not be safe.
While this is the case, evidence exists regarding the leaves’ efficiency to reduce malnutrition through its enriched protein content along with other fortified foods.
Nonetheless, effective technology for removing anti-nutrients and cyanogenic glucosides while retaining the valuable nutrient has yet to be developed (source: Horizon ePublishing Group).
In a study conducted in the southern part of Nigeria, cassava leaves are often used to make soup for nutritional and medicinal purposes. While the leaves contain significant amounts of protein, they also have cyanide, unbeknownst to many who choose to consume the soup.
Older leaves contained more cyanide than young, tender leaves. But, even when lower cyanide was consumed in cassava which was reported to be not lethal, long-term consumption caused serious health problems such as neuropathy, glucose intolerance, and even death (source: Bionature).
If you plan to eat cassava roots, leaves, flour, and bakery or snack products like cassava cake and chips. We highly recommend discussing cassava with your doctor or health provider to determine what servings you can safely consume.
We also advise you to take caution when buying cassava products, or wait until after your baby is born before you enjoy them again.