Garri is one of the staple foods in West Africa that cuts across tribes. It is made from processed cassava tubers.
Regardless of the hike in food prices over the years, garri is one food that will always find its way to the kitchen of Nigerians, regardless of economic status.
Garri comes in various granulated forms, including rough, medium and smooth, which are used to prepare different foods.
However, there has been a myth surrounding the consumption of this versatile staple, as many Nigerians have lived with the belief that it causes blindness or destroys eyesight when consumed in excess.
The National Library for Medicine, under the National Centre for Biotechnology Information in the United States, states that cassava is food to 500 million people around the globe.
It, however, notes that the presence of two cyanogenic glycosides: linamarin and lotaustralin, in cassava, is a major factor limiting its use as food or feed.
It further states that the processing techniques in cassava production are known to reduce cyanide in tubers and leaves. Drying is the most ubiquitous processing operation in many tropical countries.
The report explains that sun-drying eliminates more cyanide than oven-drying because of the prolonged contact time between linamarase and glucosides in sun-drying.
It adds that soaking followed by boiling is better than soaking or boiling alone in removing cyanide.
Data from the National Library of Medicine show that traditional African foods such as garri and fufu are made by a series of operations such as grating, dewatering, fermenting, and roasting and in the various stages of garri manufacture, 80 to 95 per cent cyanide loss occurs.
A research paper by a group of Nigerian researchers titled, ‘Visual defects among consumers of processed cassava’, shows that illnesses due to consuming smaller amounts of cyanide taken in over a long period of time can occur if cassava roots are not processed properly.
The effects, it said, can include poor vision and hearing, paralysis of the legs and unsteady walking, among others.
According to the paper, the results of the study prove that consumers of garri have poorer visual acuity and colour vision when compared with the non-consumers of garri.
It says this may be due to the exposure to unsafe amounts of cyanide in garri that is greater than 10 ppm, which is consumed over a long period of time.
The report says, “Consumption of processed cassava (garri) increases the high incidence of refractive errors among consumers, which may consequently contribute to the high prevalence of blindness and severe visual impairment in the study area.”
A popular health influencer and doctor, Chinonso Egemba, better known as Aproko Doctor, said constant intake of garri not properly processed could affect eyesight.
He said, “If it is processed properly, garri will not affect eyesight. If a person constantly takes garri that is poorly processed, it can contain small amounts of cyanide that can reduce oxygen supply to the eyes, causing severe macular degeneration.
“But it won’t just affect the eyes. When cyanide affects the eyes, it can lead to blindness. When it affects the thyroid, it can lead to hypothyroidism. The kidneys and pancreas too may be affected as it can reduce insulin production. This insulin is what regulates blood sugar.
“So, except you buy garri from wicked people who do not pass the cassava through all the processes to properly remove cyanide, it can’t be poisonous. The chances are slim. Properly processed garri will not affect your eyesight.”
Cyanide is a rapidly acting, potentially deadly chemical that interferes with the body’s ability to use oxygen.
Raw cassava contains naturally occurring forms of cyanide.
The New York Department of Health notes that the fast-acting poison was used as a chemical weapon for the first time in World War I.
It states further that low levels of cyanide are found in nature and in products humans commonly consume.
Cyanide can be produced by certain bacteria, fungi and algae. It can also be found in cigarette smoke, vehicle exhaust, and in foods such as spinach, bamboo shoots, almonds, lima beans, soy and tapioca.
A health website, Healthline, says the chemical is one of the most famous poisons that can cause immediate death.
It states, “Cyanide can refer to any chemical that contains a carbon-nitrogen (CN) bond and can be found in some surprising places.
“You can also find cyanide in certain nitrile compounds used in medications and is even a byproduct of metabolism in the human body. It’s exhaled in low amounts with every breath.”
A consultant ophthalmologist at the Lagos State University Teaching Hospital, Bolanle Balogun, said associating the consumption of garri with blindness was a myth Nigerians had lived with for too long.
She said, “There is no study to prove that garri causes blindness; it is a myth we have lived with for too long. However, cyanide is a poison that is toxic to the body and it affects the nerves, including those in the eyes.
“So, it is not the garri that affects the eyes, it is the presence of cyanide in garri that is not well processed that can affect the eyes over time, and also the nervous system of the body. Some cultures use palm oil in processing their garri, which helps in reducing the toxicity.”
The ophthalmologist said she would not advise anyone to stop consuming garri for fear of going blind.
The process of making garri starts with the cassava tubers being peeled, washed and grated or crushed to produce a mash.
The mash is then mixed with palm oil and placed in a porous bag, which is placed in an adjustable press machine for one to three hours to remove excess water.
Once dried, it is sieved and fried in a large clay frying pot with or without palm oil.
The resulting dry granular garri can be stored for long periods.
A Professor of Optometry at the Faculty of Life Sciences, University of Benin, Gladys George, explained that although properly processed garri would not harm the eyes, just one exposure to cyanide is enough to damage eyesight.
She said, “Properly processed garri will not affect eyesight or cause blindness, but if the process of fermentation and frying is not properly done, then the cyanide content will still remain.
“The chemical is toxic to the nerves and shouldn’t be consumed. What it does to the body is that its biochemical structure displaces the vitamin B12 from its receptor site. Then the body becomes deficient in B12, which in turn causes damage to the optic nerve that sends signal from the eyes to the brain, ultimately leading to loss of vision and blindness.”
George said properly processed garri, no matter the frequency of consumption, would have no negative effects on the eyes.
“If properly processed and cyanide reduced to the barest minimum, the frequency of consumption will not affect eyesight in any way. As long as the toxic effect is removed, garri is safe for consumption.
“But even if it is once that a person is exposed to cyanide poisoning, it is just enough to damage the optic nerve and cause blindness,” she added.
According to a nutritionist, Esther Johnson, garri has many health benefits, as it contains carbohydrates and dietary fibre.
She said, “Garri is a healthy food because it is low in fat and high in carbohydrates. It is also a good source of dietary fibre, which helps to regulate the digestive system and prevent constipation. Garri is also a good source of iron, as it aids red blood cell formulation which is important for healthy blood cells and growth.
“It helps to boost the immune system by keeping it healthy because it contains copper and magnesium; it helps to absorb toxins that go into the intestines. Also, garri mixed with palm oil can help to improve poor eyesight because of the vitamin A in palm oil.”
The nutritionist added, “Fermented garri left for a long period of time, such as Ijebu garri, contains bakarotennya, which is a compound that even helps to prevent blindness.”
She, however, noted that taking garri for a long period of time could increase blood sugar levels, worsen stomach ulcers and cause weight gain.
https://punchng.com/does-garri-cause-blindness
