Should Mycotoxins be mainstreamed in the Scaling
Transcript Should Mycotoxins be mainstreamed in the Scaling
Should Mycotoxins be mainstreamed in
the Scaling up Nutrition (SUN)
EXPOSURE TO AFLATOXINS
• Maize and groundnuts are the
major sources of aflatoxin
exposure in humans.
• Production of aflatoxin by fungi
present in these crops can
increase due to climatic factors
such as drought stress, rainfall
and insect damage.
• Post-harvest conditions related to
inappropriate food storage,
transportation, and processing of
crops can increase aflatoxin
AFLATOXINS AND ADVERSE HEALTH
• Aflatoxins recognized as carcinogens by the International
Agency for Research on Cancer in 1976
• Acute exposure can result in aflatoxicosis, which manifests as
severe, acute hepatotoxicity with a case fatality rate of ~25%
In 2004 and 2005 consecutive outbreaks of acute aflatoxicosis caused in
Kenya caused more than 150 deaths
• Chronic aflatoxin exposure, often in association with hepatitis B,
can result in hepatocellular carcinoma
Hepatocellular carcinoma is the sixth most prevalent cancer worldwide
Burden of hepatocellular carcinoma attributable to aflatoxins is unknown
• Chronic aflatoxin exposure may also lead to impaired immunity
Strosnider et al. Workgroup Report: Public Health Strategies for Reducing Aflatoxin Exposure
in Developing Countries. Environmental Health Perspectives. 2006;114(2):1898-1903.
HUMAN EXPOSURE TO AFLATOXINS IN
• Studies in Ghana and Nigeria1, Kenya2, Sierra Leone3 and the Gambia4
have found detectable levels of aflatoxin in cord blood samples.
• Several studies1,2,3,5,6,8 in sub-Saharan Africa have also detected aflatoxin
in breast milk samples, which indicates that children may be exposed via
• Exposure to aflatoxins in early childhood typically increases when
complementary foods are introduced, especially in regions where maize
and groundnuts are dietary staples9.
Studies in the Gambia10, Guinea11, Benin and Togo12, 13, and Senegal4 found detectable
levels of aflatoxin in the urine or serum of 85-100% of children sampled.
• Many studies have detected aflatoxins in human body fluids more often
in the wet season than the dry season.
1. Lamplugh et al. BMJ (Clin Res Ed), 1988; 2. Maxwell et al. Toxin Rev, 1989; 3. Jonsyn et al. Ann Trop Paediatr, 1995; 4. Wild et al. Lancet, 1991; 5.
Coulter et al. Ann Trop Paediatr, 1984; 6. Jonsyn et al. Mycopathologia, 1995; 7. Wild et al. Int J Cancer, 1987; 8. Tchana et al. Int J Environ Res Public
Health, 2010; 9. Khlangwiset et al. Crit Rev Toxicol, 2011; 10. Truner et al. Trop Med Int Health, 2000; 11. Polychronaki et al. Food Cehm Toxicol,
2008; 12. Gong et al. Int J Epi, 2003; 13. Gong et al. Environ Health Perspect, 2004.
AFLATOXINS AND CHILD GROWTH
Majority studies conducted in animals:
29 of 30 studies reviewed showed an association between aflatoxin exposure and food intake an/or weight
5 of 5 studies reviewed showed an association between aflatoxin exposure in utero and growth in early life1
A small number of observational studies involving humans have been conducted in sub-Saharan
Study of 125 infants in rural Kenya: mean birth weight of infants whose mothers had detectable aflatoxin in their
blood was 255 g lower than that of infants whose mothers did not have aflatoxin2
Cross-sectional study of 480 children in Togo and Benin found a dose-response relationship between aflatoxin
levels in the blood and WAZ (p=0.005) and HAZ (p=0.001)3
Study of 472 Gambian children 6-9 years of age did NOT find an association between aflatoxin levels and HAZ or
WAZ4. However, a later study in the Gambia found an association between exposure to aflatoxin in utero and
weight (p=0.012) and length gains (p=0.044) in the first year of life5.
Significant association between aflatoxin exposure and wasting (p=0.002) in Kenyan children 3-36 months of age.
No association with stunting or underweight6.
Longitudinal study of 200 children 16-37 months of age showed strong negative correlation between blood
aflatoxin levels and child growth (stunting)
1. Khlangwiset et al. Critical Reviews in Toxicology. 2011;41(9):740-755. 2. De Vries et al. Acta Paeditar Scand, 1989; 3. Gong
et al. BMJ, 2002; 4. Turner et al. Environ Health Perspect, 2003; 5. Turner et al. Int J Epidemiol, 2007; 6. Okoth and Ohingo; Afr
J Health Sci, 2004.
INTERPRETATION OF THE EVIDENCE
Strong evidence showing exposure to aflatoxins is common among children in
several sub-Saharan African countries where maize & groundnuts are dietary
staples and included in complementary foods for infants.
This exposure is likely contributing to reduced immunity and morbidities
(aflatoxicosis, hepatic carcinomas, etc)
Some evidence that post-weaning exposure to Aflatoxins impairs child growth
However, precise effects and pathways of aflatoxin exposure on child growth still
Most studies have been conducted in animals;
All human studies have been observational with relatively small sample sizes, and have
produced mixed results.
These studies illustrate correlations between aflatoxin exposure and reduced growth,
but do not prove causation (albeit RCTs not advisable/ethical) or pathways for impact
Aflatoxins may be one of many factors contributing to child stunting in sub-Saharan
Africa, but more research is needed to establish causation and the precise burden.
The “Window of Opportunity” for Improving
Nutrition is very small…
…pre-pregnancy until 18-24 months of age (1000 days)
Weight for age Z-score (NCHS)
Latin America and Caribbean
Actions after age two
0 3 6 9 12 15 18 21 24 27 30 33 36 39 42 45 48 51 54 57 60
Age (m onths)
Malnutrition usually happens from pre-pregnancy until 18-24 months of age
(1000 days) and these losses in human capital are not recovered
Repositioning Nutrition, 2006
Africa: the lagging region in the global fight
Rate of under-five stunting
A large number of the world’s
malnourished children are in Africa (60
million stunted; + 30 million
underweight; many more micronutrient
deficient) & highest proportion of DALYs
lost due to food-borne diseases.
The Scaling Up Nutrition (SUN)
call to action
Cornell University, USA
Cornell University Division
of Nutritional Sciences
National Nutrition Institute,
THE WORLD BANK
The International Life Science
Institute Focal Point in China
The multi-sectoral approach to improve nutrition
Interventions under the SUN
• Primarily through the health
sector (Breast-feeding promotion,
• Social protection
• Water & Sanitation
complementary feeding, Vitamin and mineral
supplements, deworming, etc…)
FROM A POLICY PERSPECTIVE
African children have high Aflatoxin exposure during the early years when child
growth and human capital development is critical.
Though the mechanisms are not clear, the compromised immunity, and aflatoxinrelated morbidities are likely to impact on child growth and so should be considered
among the potential “nutrition-sensitive interventions” under the SUN in high
aflatoxin burden countries
Regardless of its direct impact on stunting, aflatoxin should not remain unregulated
As of 2003, aflatoxin regulations existed for only five countries, including Kenya and South
• Focus should be on strategies that control aflatoxin-related risks in the field,
post-harvest conditions, and the diet.
Public and governmental regulations needed to provide incentives to adopt
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