An investigative report has revealed how Cyanide which a high dose of the poison present in cassava can cause a cardiac arrest as it stops oxygen from getting to the heart and the brain.
Garri a derivative of cassava, is one of the staple foods of Nigerians that provide high energy to consumers. However, it exposes the populace to possible slow cyanide poisoning if not properly processed. Its consumption has been linked previously to sudden deaths of some families, who, unfortunately, ingested some of the product that contained very high dose of cyanide.
There are, however, two varieties of cassava in the country. The sweet cassava with low cyanide level is found towards the Middle Belt of the country, while the bitter one that contains very high level of toxic cyanogenic glycosides are prevalent in the southern part of the country. These cassavas are processed for consumption differently.
Cyanide is more concentrated on the skin of the sweet variety. Once the skin is removed, it can be boiled or roasted and eaten with oil. It has been confirmed that oil has a way of neutralising cyanide. This process cannot be tried with the bitter one, as it will result in instant death.
One cup of Garri is said to contain up to 360 calories. This high energy supplying food, when properly processed, can be mixed with hot water to form Eba, eaten with different types of soups. It can also be eaten directly, soaked in cold water mixed with sugar and additional condiments like roasted groundnut, fresh coconut, and dry fish.
Currently, garri producers and marketers, out of the need to make profit, do not allow the product to go through all the processes needed to get the cyanide to non-toxic level. Cyanide reduces the oxygen supply to all the cells of the body and attacks every vital organ of the body.
The eyes, kidneys and the pancreas are not spared. It has also been implicated in severe macular degeneration, which leads to blindness and hypothyroidism, a disorder of the thyroid. Cyanide reduces the body’s ability to produce insulin.
According Doctor Chinwe Ezirim, it has been linked to diabetes in people that do not have any family history of such. Oxygen gives life, so anything that reduces its supply to the cells and subsequently to the organs is out rightly dangerous.
Symptoms of cyanide poisoning
Cyanide is very toxic but difficult to detect in many instances, except when consumed in a fatal dose. High dose of this poison present in cassava can cause a cardiac arrest,. as it stops oxygen from getting to the heart and the brain. It suffocates the consumer and most of the time leads to sudden death.
Prolonged consumption of it, in small doses, may subsequently lead to destruction of major organs in the body and to untimely slow death. Its symptoms include and are not limited to these: shortness of breath, headaches, dizziness, vomiting, general weakness, abdominal pains, confusion, bizarre behaviour, excessive sleepiness coma and seizures.
Garri, which is the granulated powdery form of cassava, has to go through many processes to become edible. The traditional method involves peeling and grating the cassava roots into pulp. Presently, grinding machines are used to make the process faster. The ground pulp is then packed into hessian bags and tied with ropes compressed tightly to ferment and drain for not less than three days. The longer they stay in this stake the more the cyanide is removed from the garri.
When fermented and properly dewatered, the product is untied, sieved to remove remaining fibrous materials and then fried with red oil over low heat in large frying pan. This step also helps to reduce the cyanide level, reduce moisture, and preserve it. Adding the red oil introduces Vitamin A into the garri granules.
Speaking on this, Dr. Mercy Ifeanacho of the Biochemistry Department of the University of Port Harcourt said: “The whole essence of processing the bitter variety is to reduce the cyanide level, which is the implicated toxic substance. In trying to do this, we engage many processes, which depends on steps, sequence and time.
"In fermenting cassava, you peel grate and dewater. While it is being dewatered, fermentation takes place. When we are talking about it we should realise those micro organisms are involved. In fermentation of garri, serial fermentation is involved.
“Some group of bacteria starts the work and lactic acid is increased during this process. This will reduce the P.H. level of the garri. Another set of micro organisms then takes over and further increase the acid level reducing the P.H. The length of time will determine the quantity of cyanide that will be removed from the cassava.
"That is why when you ferment garri for a shorter time; there will be higher cyanide retention. The level of cyanide retention is further reduced, after fermentation during roasting of product on fire. There is a chemical process that takes place between the oil added during roasting of garri and any cyanide present. The presence of red oil actually neutralises the toxic effect of cyanide in garri so red garri is safer than the white one.”
On whether fruits and vegetables flush out cyanide from our system, Ifeanacho saids it was possible, as vegetables and fruits are loaded with vitamins and minerals.
According to him, “the elemental nutrients are known to contain some kind of anti-oxidants. I am not sure of the digestibility of cyanide, but foods high in fiber have a way of pulling waste out of the body. That way it will not allow cyanide to stay longer in the body to cause further harm to the body.”
Giving tips on how to identify garri not properly processed properly, he said: “Traditionally and locally, when people want to buy garri from the market, there are ways of testing for good ones. For someone that is economically minded, like hoteliers and owners of restaurants, they will rather buy ones that are starchy because it tends to give more volume. For home consumption, one should buy garri that is properly fermented. It will show in the colour of the product. Garri that is properly processed is not that bright, just like you have Ijebu garri.
“Taste is another indicator of the level of cyanide in a product. If you taste it and it is sweet, that means the cyanide content is high. When it is sour, it is an indication that it may be properly fermented. If you press and it comes out free, it means it contains less moisture and the cyanogens are lower in low moisture products. People should watch out for poorly processed cassava products as they can be very toxic.”
Also speaking on this, Dr. Ezirm said food sources that contain high level of sulphur are good at holding on to the cyanide and taking it out.
He said vegetables that contains allicin compound found in onions and garlic family are also good at this, while pointing out that all vegetables and fruits that contain anti-oxidants help the body build up immunity and clear free radicals like cyanide.
“Fruits high in lutein, like banana, should be eaten regularly in areas where garri is highly consumed, as they help protect the eyes against macular degeneration,” she said, while advising that people who “love to swallow should also look for alternative sources, like fufu, pounded yam, unripe plantain paste or flour, combination of millet and guinea corn flour, as it is not easy to identify the garri that is properly processed.”