Aflatoxins link in Kenya cancer burden


Known as a family of toxins produced by certain fungi, aflatoxins have been established to be highly harmful to human beings.

Of late they have also been linked to the high cases of cancer. The best-known one is Aspergillus flavus, that attacks crops such as maize, pulses and groundnuts while in the field and in storage when they are not dried and stored properly.

Aflatoxins also lower the body’s immunity and cause permanent and irreversible stunting in children. And in cases of acute poisoning, they can lead to instant death. But in cases of long-time exposure, they are known to provoke liver cancer.

A study conducted in February this year by James Kibugu, of the Kenya Agricultural and Livestock Research Organisation (Kalro) and four others shows that these poisonous chemicals are becoming a major burden on Kenya’s health care system.

But Kenya could reduce the cancer burden if food safety standards are strictly enforced.

Kibugu’s paper published in the African Journal of Food, Agriculture, Nutrition and Development notes that common cereals like maize and wheat have total aflatoxin levels higher than Kenyan, USA, and EU standards.

As a result, lifetime consumption of these cereals leads to “high additional risk for primary liver cancer, associated with dietary aflatoxin.”

Earlier in 2021, a review paper titled: The Scourge of Aflatoxins in Kenya: A 60-Year Review (1960 to 2020) published in the Journal of Food Quality by Timothy Omara and nine others concluded that aflatoxins exposure is ubiquitous in Kenya, and that different commodities have relatively high levels of it. And this is usually above statutory compliance limits by several folds.

Omara and his co-authors argue that the spread of aflatoxins in Kenya could be linked to poor agronomic methods, low education levels, insufficient statutory regulation, and lack of awareness among citizens.

And since maize is a staple food in Kenya, low diet diversification has exacerbated exposure to aflatoxins.

But even though exposure assessments have been undertaken as a means of limiting contamination of foods from aflatoxin, Omara advises that it is necessary to diversify one's diet.

It has also been proven that rapid and proper drying, proper transportation, and packaging, as well as sorting can help in reducing aflatoxin levels.

Other mitigation measures are washing, drying, fumigation, post-harvest insect control, and the use of botanicals or synthetic pesticides as storage protectants. Climate change is proving to be a problem as well.

The traditional ground-based drying that we have used for ages is no longer effective. And with the temperature swings happening between day and night affecting how we dry our products, this can further increase the level of aflatoxins.

There are also not many commercial products that can be used to offer risk mitigation to the contaminated crops: one technique applies during the growth of the crop, neutralising parasites like the maize stem borer, a bug that carries the spores of Aspergillus when penetrating the cob.

In general, current techniques for abating aflatoxins in crops do not guarantee full eradication, but only a percentage promise. If a product is highly contaminated from the start, even if there is treatment, harmful quantities will still be present.

In my view, the safe alternative is to invest in controlled drying processes. New research also reveals that emerging experimental treatments such as, radiation and light treatment, thermal pressure, and plain chemical agents have not been proven effective outside the controlled lab environments.

Illicit market practices complicate matters because produce declared unfit for human consumption can be diverted by unscrupulous traders into the animal feed chain, bringing contamination to our tables in other products like meat, poultry or even milk to cite a few.