Transcript Should Mycotoxins be mainstreamed in the Scaling

Should Mycotoxins be mainstreamed in
the Scaling up Nutrition (SUN)
Movement?
Meera Shekar
World Bank
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
production.
AFLATOXINS AND ADVERSE HEALTH
OUTCOMES
• 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
SUB-SAHARAN AFRICA
• 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
breastfeeding.
• 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
gain1
•
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
Africa:
•
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
unclear:
•
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)
0.50
Weight for age Z-score (NCHS)
0.25
0.00
-0.25
Latin America and Caribbean
Africa
Asia
-0.50
Actions after age two
Too late
Too expensive
Too little
-0.75
-1.00
-1.25
-1.50
-1.75
-2.00
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
against malnutrition
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)
Global Movement
ONE unified
and powerful
call to action
...Building
a Global
Nutrition
Movement
Cornell University, USA
Cornell University Division
of Nutritional Sciences
National Nutrition Institute,
MOH Egypt
THE WORLD BANK
Public-Private Partnerships
The International Life Science
Institute Focal Point in China
The multi-sectoral approach to improve nutrition
Interventions under the SUN
“Nutrition
specific”
interventions
• Primarily through the health
sector (Breast-feeding promotion,
“Nutritionsensitive”
interventions
through
• Agriculture…..
• Social protection
• Education
• 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
in Africa:
•
As of 2003, aflatoxin regulations existed for only five countries, including Kenya and South
Africa
• 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
interventions.
For more information:
Worldbank.org/nutrition
Scalingupnutrition.org
http://siteresources.worldbank.org/NUTRITION/Reso
urces/281846-1131636806329/NutritionStrategy.pdf
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UTRITIONANDPOPULATION/EXTNUTRITION/0,,contentMDK:2255578
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