The Role of Mycotoxin Contamination in Nutrition:

The Aflatoxin StoryAmare Ayalew (PACA), Vivian Hoffmann (IFPRI),

Chibundu N. Ezekiel (PACA), and Jahanna Lindhal (ILRI)

Objectives:• Highlight the linkage between food safety and

nutrition security and economic development• Highlight mycotoxins as a major food safety

challenge• Describe nutrition and health and economic

implications of aflatoxins; the extent of contamination and sources of exposure

• Describe contribution of mycotoxin control to major developmental agenda

• Highlight options for aflatoxin management and outline action areas

Globally accepted definition of food security expressly links nutrition and food safety:

• Food security exists when all people, at all times, have physical access to sufficient, safe and nutritious food which meets their dietary needs and food preferences for an active and healthy life.

Unfulfilled linkages between food security, nutrition and food safety

• Disproportionate focus on supply, with emphasis on food production and stock availability

• Over the last decade, the necessity to embed nutrition into agriculture is well recognized

• Unsafe, contaminated foods stilll thwart food security and nutrition

Food safety impacts food security and nutrition and development

• Unsafe food is not food – contaminated food could cause disease, immune suppression and stunting

• When contaminated crop is withdrawn from the supply chain the quantum of food is directly impacted

• Food contamination affects access to markets and rural incomes, and thus access to food but also economic well-being

Mycotoxin contamination is a major food safety challenge Mycotoxins are toxic compounds, harmful to human and

animal health, that are produced by some fungi Contamination of food with mycotoxins is a prominent food

safety challenge in tropical regions. In Africa, aflatoxins and fumonisins are the most important

mycotoxins Aflatoxins receive priority attention due to:

• high pre- and postharvest contamination potential• widespread occurrence in diverse foods and animal feeds• extreme toxicological significance to humans and animals, • impacts on food safety, nutrition, public health, and

markets and income

Aflatoxins impact on three sectors (most pervasive food safety challenge in Africa)

Public health

Food and nutrition security

Trade and

economy

Nutrition and Health Implications of Aflatoxins• Acute effects which are often fatal• Chronic effects:

• Liver cancer: • 40% of global liver cancer cases occur in Africa• Aflatoxin contributes to upto 30% of the liver cancer cases

• Immunosuppression aggravating HIV, malaria• Childhood growth faltering (underweight and

stunting and reduced cognitive development):• interfering with absorption and metabolism of vitamins

and minerals, protein malnutrition, gastrointestinal toxicity

Nutrition and Health Implications of Aflatoxins: Exposure Sources• First 1000 Days

• During pregnancy• During breastfeeding• via the introduction of complementary weaning

foods • Throughout the life of an individual:

• Through consumption of contaminated foods• Particularly susceptible foods include maize,

groundnut, sorghum, tree nuts and processed cassava

• Occupational exposure: grain dust

Aflatoxin exposure in 1,000 days of life:

Complementary/weaning foods(450 – 1000 days; AFB1, AFG1 & AFM1)

Trans-placental exposure

(0 – 270 days; AFB1)

Breastmilk(270 – 450 days; AFM1)

Maternal exposure

Nutrition: consumption of aflatoxin contaminated foods

Cow milk and other milk-

based products

Cereal, tubers and nut-based

foods

Premature introduction (360 – 450 days)

Neonataland infant exposure

- Low birth weight- Impaired growth- Cognitive development- Impaired immune function- Impaired GIT function- Stunting

Economic Impacts of Aflatoxins• Loss from mortality and morbidity• Export markets

• aflatoxins need to be managed if the continent is to reclaim a share in global groundnut trade and many other agricultural commodities

• Smallholder market access• Aflatoxin is major part of quality and safety requirements of

premium buyers• Smallholder farmers unable to comply with food safety standards

denied opportunity for income growth• Livestock productivity (no estimates of economic

consequences in livestock subsector in Africa)• impacts on livestock weight gain and productivity; mortality;

contamination of milk, egg and meat• Susceptibility: pigs> turkeys>chicken>cattle

Prevalence of Aflatoxins in Major Food Supply Chains

• East and West African regions as well as North Africa exhibit both the highest rates of contamination and levels of the toxin

• In a wide range of foodstuffs, the most severely contaminated crops are maize and groundnuts

• Other foods, including sorghum, tree nuts, spices and processed cassava, can also be important sources of aflatoxins but contain lower levels or constitute smaller shares of diet; animal source foods especially milk

• Animal feed (concentrates) can be heavily contaminated

On average 40% of commodities in local African markets exceed allowable levels of aflatoxins

in foods

Aflatoxin levels exceeding 1000 ppb are not uncommon.

Aflatoxin M1 in milk in some African countriesLocation Samples Positive >50 ppt >500

pptMax level detected

Reference

Dar es Salaam, TZ

37 92%   24% 855 ppt (Urio et al. 2006)

Nairobi, Kenya

128 100% 63%   2,560 ppt (Kiarie et al. 2016)

Rural Kenya (4 AEZ)

512 40% 10% 0.6% 6,999 ppt (Senerwa  et  al. 2016)

Libya 49 71%     3,130 ppt (Elgerbi et al. 2004)

Addis Ababa, Ethiopia

110 100% 92% 26% 4,980 ppt (Gizachew  et  al. 2016)

Cameroon 63 16% 9.5%   527 ppt (Tchana et al. 2010)

Factors influencing aflatoxin risks in Africa

Aflatoxin challenge in Africa

Conducive climatic 

conditions

Complexity – difficulty of targeting 

interventions

Heavy reliance on dietary staples

Low awareness levels

Traditional crop 

production practices

Weak institutional capacity

Groundnut shelling, Senegal 2015, improvements neededPhoto: PACA

Managing aflatoxins• Need for systemic thinking and integrated

multidisciplinary and multi-stakeholder approach• A mix of preharvest and postharvest measures

• Proper agronomic and crop management practices • Competitive biological control using non-aflatoxin

producing strains of A. flavus can reduce toxin levels by 80-90% (Atehnkeng et al. 2014).

• No commercial lines with resistance to address aflatoxin contamination have been marketed (Brown et al., 2013) but need to explore recent advances in plant breeding

• Proper drying to safe moisture levels• Clean and dry storage• Hermetic storage solutions

Managing aflatoxins, cont.• Regulatory measures: enforcing max limits• The developed world applies effective inspection of food

supplies and enforcing maximum limits for aflatoxins • Tradeoffs between food safety and availability cannot be

ignored• Developing legal, alternative non-food uses for

contaminated produce • African countries cannot continue with the status quo of

enforcing regulations only in produce destined for export markets

• Market incentives to drive behavior change play important role in adoption of aflatoxin control strategies across food systems

The Mycotoxin Agenda:Relevance of mycotoxin control to meeting Malabo Declaration Commitments, Agenda 2063, and SDGs• Malabo Declaration Commitments on:

• #3, ending hunger in Africa by 2025 • #4, poverty reduction• #5, tripling intra-African trade in agricultural

commodities and services• #6, enhancing resilience of livelihoods and production

systems to climate variability and related risks• Sustainable Development Goal on ending

poverty and hunger

Role of the Partnership for Aflatoxin Control in Africa (PACA)• Working with country

governments, RECs and other stakeholders and driving systemic change in aflatoxin mitigation in Africa

• PACA supports AU member states from evidence generation through development, implementation and progress tracking of comprehensive aflatoxin control action plans

Potential interventions for addressing nutrition and health impacts of mycotoxins

• Thematic area 1: Health - Targeting Hepatitis B virus (HBV) vaccination & other control options; surveillance and biomonitoring;Public health policy on aflatoxin in Africa

• Thematic area 2: Agriculture - Pre-harvest practices, post-harvest interventions;Market demand driven technology adoption;Alternative uses of contaminated crops;Smallholder farmer adoption of practices

• Thematic area 3: Nutrition- Mitigating aflatoxins in food fortification supply chains;dietary diversification;food processing, food quality and safety

Please refer to the key action items and stakeholder roles in Chapter 8 of ATOR 2015.

Conclusions• Aflatoxins, potent carcinogens in human and animals,

mainly get into the biological system via diets• The human health impacts resulting from acute and

chronic aflatoxin exposure adds losses in productive years and cost of illness, contributing to the cycle of poverty which may contribute to further ill-health

• Several interventions are available for reducing the adverse impacts of aflatoxins

• However, the complexity and cost of implementing the available strategies requires effective partnerships

• There is a need to embed aflatoxin control in value chain development efforts involving susceptible commodities

Thank You