There's an urgent need to quantify the role of fungal toxins (aflatoxins), found on agricultural crops, such as maize and peanuts (groundnuts), in the escalating rates of liver cancer in Ghana, as well as elsewhere in Africa and Asia, concludes a commentary published in the open access journal BMJ Global Health.
Maize and peanuts are dietary staples in many Asian and African countries. And with one of the highest rates of liver cancer in Africa, at 16/100,000 of the population. Ghana represents a critical case study in furthering international understanding of the link between aflatoxins and the rising global toll taken by liver cancer, say the authors.
Aflatoxins are produced primarily by Aspergillus flavus and Aspergillus parasiticus, which thrive in warm humid conditions, and can occur at any point during harvest and storage.
There are several known risk factors for liver cancer, explain the authors. These include chronic infection with hepatitis B and C viruses—the prevalence of which is high in Ghana—liver cirrhosis, heavy drinking and smoking, and genetic and metabolic conditions, such as diabetes and obesity.
While the International Agency for Research on Cancer (IARC) has classified naturally occurring aflatoxins as Group 1 human carcinogens, no study to date has specifically assessed the contribution of aflatoxin exposure to the high incidence of primary liver cancer in Ghana, despite the high consumption of foods contaminated with these toxins and the prevalence of hepatitis, point out the authors.
The Ghanaian government has taken several steps to curb contamination and public exposure to aflatoxins. These include promoting good agricultural practices, improved storage methods, solar drying techniques, pest control, regular monitoring of food and feed products, and raising public awareness of the hazards of aflatoxin exposure, note the authors.
But without solid evidence, it's difficult to understand the exact extent of the exposure and its impact on public health, they add.
For example, few large scale epidemiological studies involving different demographic groups, geographic regions, and rural and urban populations in Ghana, have been carried out. And the combined effects of multiple risk factors on liver cancer development are still poorly understood, say the authors.
Improved surveillance and monitoring systems are needed to assess the effectiveness of current aflatoxin control measures in the country. And better understanding of socioeconomic and cultural factors could inform safer food practices at the household and community levels, they suggest.
"This research is vital to informing targeted interventions, refining existing policies, and ultimately reducing the burden of liver cancer in the country," insist the authors.
If these research gaps are plugged, the benefits will be felt not only in Ghana, but elsewhere, including many countries in Sub-Saharan Africa and Asia, they add.
"Ghana can better protect its population from the deadly consequences of aflatoxin exposure and contribute to global efforts to curb the growing burden of liver cancer," they write, highlighting that liver cancer ranks among the leading causes of cancer-related deaths worldwide.
There were over 700,000 deaths from liver cancer reported in 2022 alone, with the toll taken by the disease projected to keep on rising: between 2020 and 2040, new cases are expected to rise by 55%, with associated deaths increasing by more than 56%, emphasise the authors.
