Natural food toxins: Our silent killers

The Ghanaian consumer perceives anything natural to be safe in oblivion and rather seems to concentrate on the harmful effects of synthetic chemicals, novel processing, irradiation, pesticide residue, etc. 

They were prominent among consumers as notable sources of toxic materials in a survey performed in 2021. As difficult as it is to believe that our natural toxins equally or perhaps put us at more risk is unthinkable. Consumers may be unaware of or have low knowledge levels of the toxins that naturally occur in food.

Historically, we have been schooled on the potential toxicity of everything; where only the dose divides the toxic from the non-toxic.

Water, a universally acclaimed vital substance is toxic if a large quantity (4-5 litres) is consumed in a relatively short period (2-3 hours) and this often results in hyponatremia and subsequently cerebral oedema, seizures, and finally death as the pathogenesis of intoxication, according to scientists.

Food, even though nutritious and inevitable, may on some occasions pose threats to the consumer. Foods may contain both friendly and unfriendly microorganisms; these microorganisms are not harmful to the organisms themselves, but they may be toxic to other creatures, including humans when consumed.

Natural toxins are toxic compounds that are naturally produced by living organisms. When eaten, these toxins may cause deleterious several effects on human and/or animal subjects.

Their effects may include toxicity (poisonous) to the nervous system (brain and spinal nerves), hepatic and nephrons (liver and kidneys), cardiovascular and circulatory systems (heart and blood), and immunotoxic (poison to the immune system). Their effect may either be acute or chronic.

During periods of climate stress (drought or extreme humidity), plants and other microorganisms produce some toxins that are used as a natural defence mechanism against predators, insects or microorganisms. Interestingly, these toxins are not harmful to the organisms themselves but may be toxic to other creatures, including humans.

These chemical compounds have diverse structures and differ in biological function and toxicity.

Some toxins are produced by plants as a natural defence mechanism against predators, insects or microorganisms or as a consequence of infestation with microorganisms, such as mould, in response to climate stress (such as drought or extreme humidity).

Furthermore, toxicities from herbal medicinal preparations can be traced to plant toxins and high levels of phytochemicals which go a long way to causing problems for our internal organs (kidneys, liver, etc.) if not properly checked and regulated.

Other sources of natural toxins are microscopic algae and plankton in oceans or sometimes in lakes that produce chemical compounds that are toxic to humans but not to fish or shellfish that eat these toxin-producing organisms.

When people eat fish or shellfish that contain these toxins, illness can rapidly follow. Some of the most commonly found natural toxins that can pose a risk to our health are described below.

Fungal origin
Mycotoxins

Mycotoxins are naturally occurring toxic compounds produced by certain types of moulds. Moulds that can produce mycotoxins grow on numerous foodstuffs such as cereals, dried fruits, nuts and spices. Mould growth can occur before harvest or after harvest, during storage, on/in the food itself often under warm, damp and humid conditions.

Most mycotoxins are chemically stable and survive food processing. The effects of food-borne mycotoxins can be acute with symptoms of severe illness and even death appearing quickly after the consumption of highly contaminated food products.

Long-term effects on the health of chronic mycotoxin exposure include the induction of cancers and immune deficiency. Many have been classified as potent carcinogens by the International Agency for Cancer Research (IARC).

Mycotoxin Clearance from Human Factor VII – BioProcess International The Promise of GMOs: Mycotoxins – GMO Building Blocks Contamination due to mycotoxins is a serious food safety and security concern that has had confrontational monetary consequences, as well as health penalties in agricultural regions across the globe, especially sub-Saharan Africa.

The danger involved in their association with food commodities is their obstinate persistence and their ability to stay potent even through rigorous processing and treatment as a majority of them are very fatal and stable and thus are of significant importance in food safety. These mycotoxins accrue finally in the liver of human bodies in an active state as a relocation from animal bodies via poisoned animal products.

Toxicogenic fungal infection impacting mycotoxins in our foods

Several hundred different mycotoxins have been acknowledged (over 400 and counting) but the most commonly observed mycotoxins that present a concern to human health and livestock include aflatoxins, ochratoxin A, patulin, fumonisins, zearalenone and nivalenol/deoxynivalenol.

The symptoms of a mycotoxicosis (poisoning due to fungi toxin) depend on the type of mycotoxin; the amount and duration of the exposure; the age, health and sex of the exposed individual; and many poorly understood synergistic effects involving genetics, dietary status and interactions with other toxic elements.

Thus, the severity of mycotoxin poisoning can be compounded by factors such as vitamin deficiency, caloric deprivation, alcohol abuse and infectious disease status.

Furthermore, poisoning from fungal toxins can heighten vulnerability to microbial diseases, worsen the effects of malnutrition, and interact synergistically with other toxins.

Poisonous mushrooms

The ingestion of Amanitins, muscimol, muscarine, and other toxins which may be present in wild mushroom species such as Amanita phalliodes, Lepiota brunneioncarnata, Cortinarius orellanus shown in the picture etc., can lead to nausea, diarrhoea, confusion, visual abnormalities, salivation, and hallucinations.

Six to twenty-four hours or more after eating mushrooms, symptoms start to appear. Fatal poisoning is typically accompanied by a slow onset of symptoms that are quite severe and have a toxic impact on the neurological, liver, and kidney systems.

The poisons are not rendered inactive by cooking or peeling. Any wild mushrooms should be avoided unless they have been positively identified as non-poisonous. Mushroom lovers are advised to eat only familiar mushrooms and NOT look-alikes, especially when they go hunting during these rainy seasons.

Notwithstanding, to avoid all unnecessary doubts, one could purchase mushrooms from the list of domesticated mushrooms such as Pleurotus sp. (oyster mushrooms), oil palm mushroom (Domo) etc.

Plant Origin
Solanines and chaconine

Solanines and chaconine, which are glycoalkaloids, are naturally occurring poisons found in all Solanaceae plants, which include tomatoes, potatoes and eggplants. Although levels are often low, potato sprouts, bitter-tasting peel and green sections, as well as green tomatoes, have higher concentrations.

In reaction to stresses, including bleeding, Ultraviolet exposure, pathogens, and attacks from insect pests and herbivores, the plants create poisons. It’s vital to store potatoes in a dark, cool, and dry place and to avoid eating the green or sprouting parts to limit the development of solanines and chaconine.