Natural toxins in food (4): Is cyanide the natural toxin medicinal?
By Kemi Ilori
Tuesday, March 13, 2007

Last week, we were able to know that cyanogenetic plant foods are a natural part of our diet. How come we are not poisoned by the hydrogen cyanide? Most plant foods undergo processes, which remove almost all the cyanide in them. Cassava, (Manihot utilissima) is a very good example. Cassava contains a compound called manihotoxin which gives off hydrogen cyanide when the fleshy root is processed. The name of this natural food toxin is self explanatory – manihot – toxin. Some texts wrongly refer to manihotoxin as linamarin. Linamarin is obtained from Linseed not Cassava. It however has an identical constitution with manihotoxin. This food processing involves the soaking of the cassava root flesh in water for a given period of time. The manihotoxin is hydrolyzed and the cyanide released as hydrogen cyanide.

This detoxifies the cassava. There have been unfortunate instances of cases where a whole family would die after eating a meal of improperly hydrolyzed cassava e.g. Garri meal made from hurriedly processed cassava which was not allowed to hydrolyse off all the hydrocyanide. What are the signs of cyanide poisoning? The signs and symptoms of cyanide poisoning range from headache, difficulty in breathing and vomiting to unconsciousness and death.
A lot of people will wonder that how does cyanide kill ? At low doses, your body can cope with minute amounts of cyanide), but a "large" sudden dose poses a serious medical emergency. Hydrogen cyanide (HCN) is highly poisonous to all humans and animals because it rapidly inactivates cellular respiration thereby causing death. This means that it stops cells from being able to use oxygen. The heart, respiratory system and central nervous system are most susceptible to cyanide poisoning and cease to function as a result of lack of oxygen.

This kind of poisoning is acute poisoning and leads to instant death. There are cases where the amount of cyanide ingested by an individual is high enough to be toxic (i.e. beyond what the body can handle), but not enough to cause death. This can be described as sub – acute poisoning. Sub – acute levels of cyanide will over time cause a variety of chronic effects in humans and animals. One of such conditions is known as tropical ataxia. This condition affects the central nervous system and has been identified in some Nigerian men. This does not mean that it is exclusive to them. It alters the walking gait and gives a staggering gait as if the person is drunk. As I mentioned last week, cyanide poisoning from cyanogenetic food plants is very low indeed. People should not be discouraged from eating them as they have plenty of nutritional benefits. Strange as it may seem, these toxic compounds have their own uses as well. I will explain this in due course. Lets us briefly look at how the body detoxifies cyanide.

How does the body detoxify cyanide? I am sure at least a few people will be shocked that the body can handle cyanide at all! In small doses, cyanide in the body can be detoxified in at least two ways. Cyanide is converted to a non – toxic form called thiocyanates with the help of intestinal bacteria (remember the beneficial bacteria I always hammer on!) using nutrients from some type of protein (specifically sulphur-containing amino acids). There are two important lessons you must learn here. It means that for your body to function well you need to have different nutrients. The second mode of detoxification which I will mention is done with the help of vitamin B12. The interesting thing is that provitamin B12 converts hydrocyanide to cyanocobalamin, another form of vitamin B12 which the body can still use. This means that, not only does the body detoxify the hydrocyanide, it also converts it to a nutrient! A lot of scientists with special interest in this area of research are intrigued by the link and inter – relationship between cyanogenetic foods and vitamin B12.

Medicinal Uses: As far back as about 37years ago, a scientist called Ernst T. Krebs, Jr., submitted in a paper published in a research journal; that some cyanogenetic substances in food should be designated as vitamin B17! (For the interested readers, they are beta – cyanogenetic glycosides have been designated as vitamin B-17 or nitriloside). In this paper, Krebs went further to state that cancer itself might be another chronic metabolic disease that arises from a specific vitamin deficiency--a deficiency specifically in vitamin B-17 (nitriloside)? I am not saying that Krebs is right or wrong, all I know is that in science, sometimes the answers to certain questions are found by going back to see work that had been done by certain people (just as the practices of primitive people sometimes give a clue and direction to health questions). It is important that this kind of call should not be ignored. Everybody knows and uses vitamin C today, but in the past, millions of people died of scurvy – a disease cured by simple vitamin C before it was discovered as the cure. Presently, a Mexican doctor, Francisco Contreras, runs a Christian hospital which challenges conventional medical wisdom.

The Hospital Oasis of Hope in Tijuana, Mexico, just 30 minutes from the San Diego Airport, uses natural chemotherapy Vitamin B-17 (also called laetrile), to treat cancer. This has been approved in Mexico but not in the United States. There was a part that caught my attention in Krebs’ paper. It was his reference to chronic hypotension has being reported in Nigerians who eat quantities of the nitriloside-containing manioc (cassava)--especially that of the bitter variety. I would assume that the nitrosile in this case would be manihotoxin. I know that cassava contains substances called coumarins, which help to thin the blood. The cumulative effect of this is that eating cassava could help to lower blood pressure! With the right type of funding, we have a rich atmosphere for research. Other present day uses of cyanogenetic plants by trained herbalists in extremely low dose include the treatment of persistent, dry, irritant cough and uterine fibroids, to name a few.