Africa’s staple food cassava: turning toxic with cyanide due to carbon emissions

Cassava is touted by the UN Food and Agriculture Organization (FAO) as the savior of Africa, being a staple food of more than half a billion of the world’s poorest people. The crop augurs well in the continent because it is basically drought-resistant. But one of the most important foods on the planet is becoming increasingly toxic due to carbon dioxide emissions. Cassava is one proof that climate change affects the world’s poorest people the most. New studies confirm that increasing carbon dioxide in the air boosts cyanide levels in cassava leaves.

According to Ros Gleadow of Monash University in Melbourne, Australia, “Cassava is a fantastic crop. But there is an urgent need to develop varieties that produce less cyanide.”

Gleadow discovered that ‘doubling CO2 levels in the air doubles glycoside production in cassava leaves.’ Since the trend points to CO2 levels expected to double from their pre-industrial levels by the middle of this century, Gleadow asserts that ‘cyanide poisoning will be a growing problem.’ ‘Cassava leaves and roots both contain glycosides that break down to release toxic hydrogen cyanide when chewed or crushed.’ The plant’s roots do not become more toxic, but they shrink in size.

African villagers use ground cassava roots to make their staple flour. A further process may remove the cyanide. However, cassava leaves are usually eaten raw. Cyanide poisoning from the leaves cause a condition called konzo that permanently paralyzes the legs. In one study, it was found that 9 percent of Nigerians have been afflicted with cyanide poisoning from toxic cassava.


Via New Scientist

cassava crops in Africa