S Grantham-McGregorCentre for International Health and Development Institute of Child Health University College London
Early child development in
developing countries:
the role of nutrition and stimulation
Ackowledgements
Jamaica
• S Walker, S Chang, C Powell,
• H henningham, J Meeks Gardner
Bangladesh
• J Hamadani, F Tofail, S Huda
Childpoor early development
poor school achievementbehavioural problems
Implications: Intergenerational transmission of poverty
adultlow educational level
low skilled job / no work high fertility
stressed
Poor nutrition,care &stimulation
Natio
Focus on early childhood
Sensitive period when experience has maximum
effect on brain development (conception- 5 yrs)
Effects of insults and interventions can be lasting
Ability on entry school progress productivity
Early interventions more cost effective than later
• > 200 million children < 5years in
developing countries are failing to
reach their potential in cognitive and
socio-emotional development
The Problem
(Lancet child development series 2007)
% of disadvantaged children <5yrs by region
0
10
20
30
40
50
60
70
S-S Africa Mid East & NAfrica
S Asia E Asia &Pacific
La America &Caribbean
Central & EEurope
Grantham-McGregor et al 2007;Lancet series
Cumulative Effects: Vocabulary scores by SES quartiles in 3 to 6 yr old children in Equador
age in months ( Paxson and Shady 2005)
Timing of cognitve gap: Timing of cognitve gap: Mental Mental development by wealth quintiles at birth in development by wealth quintiles at birth in 1,579 children in rural Bangladesh
-0.8
-0.6
-0.4
-0.2
-0
0.2
0.4
0.6
0.8
7 18 63 Age in Months
Z scores
Hamadani unpublished
Problem BayleySolving MDI
WPPSI IQ
• What is the role of nutrition and lack of stimulation in decline in developmental levels in the first 5 years?
Prevalence of nutritional deficits in children <5 years in developing countries 9 (Black et al 2008; UNICEF 2110)
Stunting = 192.5 million (34%)
Wasting = 73.6 million (13%)
LBW =16% - IUGR = 11%
Iron deficiency anaemia = 158.6 million (28%)
Iodine deficiency ?35% of total population
Intra-uterine growth
restriction
(11% of births)
Consistent evidence for poorer development up to age 3 years.
Limited evidence from developing countries at later ages
• 8 longitudinal studies of anaemia in early childhood followed to 4 – 19 years
• All but one showed sustained deficits
Iron deficiency anaemia 158.6 million (28%)
Cantwell 1974, Palti 1983, Lozoff 2000, De Andraca1991,
Wasserman 1994,Dommergues 1989, Hurtado 1999, Sherriff 2001
Longest follow-up: Cognitive scores to 19 years Longest follow-up: Cognitive scores to 19 years by iron status and SES, Costa Ricaby iron status and SES, Costa Rica
Age, years
Cognitive scores
Lozoff et al 2007
8 robust RCTs with iron supplementation in children <3 years (lasting 2 months)
• 6/8 benefited motor development
• 2/7 benefited mental development
Moffatt 1994, Freil 2003, Black 2004, Lind 2004, Olney 2006, Stoltzfus 2001, Idjradinata 1993, Aukett 1986,
7 RCTs with multiple micronutrients
• 5/7 benefited motor development
• 1/3 benefited mental development (not randomised)
Black 2004, Olney 2006, Abdu-Afarwuah 2007, Faber 2005, Dhingra 2004, Katz 2010, Chen 2010
Effects of multiple micronutrient & iron supplementation
• Usually benefits motor development
• Insufficient evidence for effect on mental development
• treatment duration insufficient OR irremediable?
• Insufficient evidence to show that multiple micronutrients better than iron alone
Effects of stunting (height/age ≤ -2SD) <3yrs on later cognition or grades attained
-1.5
-1.1
-0.7
-0.3
0.1
0.5
cognition z scores
grades
S Africa Indonesia Peru Jamaica
z scores/ grades
9yrs 17-18yrs 21- 41 yrs
Grantham-McGregor et al Lancet 2007, Martorell et al 2010
7yrs 9 yrs Guatemala, Pelotas,
Philippines, India
Comprehensive deficits: Jamaican children stunted before 2 yrs
at 17 & 22 yrs
• IQ, cognitve function
• Reading/ maths/ school drop out
• Depression, anxiety, self esteem, hyperactive, attention
• School suspension/ expulsion
Walker et al 2005, 2007,2010
9 RCTs of macronutrient supplementation9 RCTs of macronutrient supplementation
Pregnancy
Bangladesh
Taiwan
Pregnancy + early childhood
Guatemala
Bogota
Early childhood
Ghana
Jamaica
Indonesia
Indonesia
Cali
Adu-Afarwuah 2007
Grantham-McGregor 1991
Pollitt 2000
Husaini 1991
McKay 1978No effect
Pollitt 1993
Waber 1981
Tofail 2009
Joos 1983
Timing of supplement (months)
Age of Follow up (years)
Effect
P for 1m Bangladesh 5 -P+lactation Taiwan 1.5 -P + 6m Bogota 3 -P + 24m (Guatemala) 32 ++P + 36m (Bogota) 7 ?
6-20 for 4m (Indonesia) 8 +/- 1 test
9-24 for 24m Jamaica 17 -20-60 for 4m Indonesia 8 ->36 to 84m Guatemala 32 -
Sustained benefits from supplementation
Benefits from supplementation in Guatemala
age 25-42years
• Increased wage/hour (males)(supplement from birth to 36 months)
• Improved reading comprehension and reasoning (supplement from birth to 24 months)
Stein et al 2008, Hoddinot et al 2008
Timing: Effect (SE) of 1 z-score of birth weight & growth in weight <4 years on grades attained in 4
cohorts, controlling for SES
0
0.2
0.4
0.6
grades
Birthweight
Growth 0-24m
Growth24-48m
p<0.001
p<0.001
p=0.04
Martorell et al 2010. J Nutr 140
(n=7025) Brazil, Philippines, Guatemala, India
Conclusion from stunting
• Undernutrition contributes to the decline in development
• Most sensitive period 1st 24 months
• Some evidence of a sustained effect of supplementation
• Stunted children will not catch up with food alone
Low licking /grooming High licking /grooming
Length of dendrites in hippocampus related to treatment in 1st postnatal week
ApicalApical
BasilBasil
Champagne et al J Neurosci. 2008 Jun 4;28(23):6037-45.
Mean Corticosterone Levels Pre & Post Stress in Non-handled, Handled and Maternally-separated Rats
0
5
10
15
20
25
30
35
40
0 60 120
non-handled
maternal separation
handled
0
5
10
15
20
25
30
35
40
0 60 120
non-handled
maternal separation
handled
Plotsky & Meaney 1993
µg/dl
Pre-Pre-stressstress
Time (min)Time (min)
(n= 8 per group)
20
25
30
35
40
45
0 1 2 3 4 5 6
Language comprehension score at 18 months by number of play activities (n=786)
p=0.001
Hamadani, Tofail, 2009Hamadani, Tofail, 2009
20
25
30
35
40
45
1 2 3 4 5 6 7 8 9
Language comprehension score at 18 months by number of play materials (UNICEF n=786)
p=0.001
Hamadani TofailHamadani Tofail
Home visiting or centre based approaches Effect size 0.5-1 SD (Lancet child development series Paper 2)
15 of 16 intervention studies providing cognitive
stimulation show benefits to child development
Effects of visiting frequency in Effects of visiting frequency in disadvantaged children: Jamaicadisadvantaged children: Jamaica
94
98
102
106
110
pre-test post-test
DQ
Powell, 1989
weeklyweekly
fortnightlyfortnightly
monthlymonthly
no visitsno visits
75
80
85
90
95
McKay et al, 1979McKay et al, 1979
Cognitive abilityCognitive ability
Cognitive ability at 7 years by Cognitive ability at 7 years by duration of intervention; Colombiaduration of intervention; Colombia
0
1 2 3 4
periods of interventionperiods of intervention
RCT of stimulation with malnourished Bangladeshi RCT of stimulation with malnourished Bangladeshi infants: Effect on mental development index (MDI)infants: Effect on mental development index (MDI)
78
80
82
84
86
88
90
92
94
Pre-test
Post-test
intervened malnourishedcontrol malnourishedadequately nourished
Rx p< .05
Hamadani et al, 2006Hamadani et al, 2006
MDI
65
70
75
80
85
90
95
100
105
Enrolment After 6 months
control n=39
Intervention n=43
Raw mental score
Rx p < .001 Rx p < .001 0.57SD0.57SD
Raw Mental Score at Enrolment & 6 Months After Leaving Raw Mental Score at Enrolment & 6 Months After Leaving Hospital in Severely Malnourished Bangladeshi ChildrenHospital in Severely Malnourished Bangladeshi Children
Nahar et al,2008Nahar et al,2008
Primary Health Care: Effect of Intervention Primary Health Care: Effect of Intervention by PHC Staff on Children’s Development by PHC Staff on Children’s Development
JamaicaJamaica
90
95
100
105
pre-test post-test
Control n=69 Control n=69
Intervened n=70Intervened n=70
Rx p<.001Rx p<.001
Powell et al, 2004Powell et al, 2004
DQ
Integrated interventions: stunted Integrated interventions: stunted Jamaican children aged 9-24mthsJamaican children aged 9-24mths
85
90
95
100
105
110
Baseline 6 mo 12 mo 18 mo 24 mo
85
90
95
100
105
110
Baseline 6 mo 12 mo 18 mo 24 mo
DQDQnon-stuntednon-stunted
controlcontrol
Grantham-McGregor et al, 1991Grantham-McGregor et al, 1991
both Rxs
supplemented
stimulated
Sustainable stimulation benefits at 17 & 21 years
• Full IQ, verbal and performance IQ
• Reasoning, analogies, vocabulary,
• Reading comprehension & sentence completion
• Depression, anxiety, self esteem,
• Attention deficit, oppositional behavior
• Aggressive behaviour, social inhibition, general knowledge, grades
attained, exams passed, depression
Walker 2007, 2010
Mothers’ BenefitsMothers’ Benefits
•Child development and child rearing knowledge
Stimulation provided in the home
•Depression
Powell et al 2004
Change in Maternal Depression With Change in Maternal Depression With InterventionIntervention
16
20
24
28
Pre-test Post-test
Baker et al , 2005Baker et al , 2005
Intervened
Control
DepressionDepression
Summary for Stimulation
• Nearly all trials have concurrent benefits
• Malnourished/LBW children can improve
• Benefits related to intensity and duration
• Can have sustained & comprehensive benefits
• Mothers benefit
Timing of cognitve gap: Timing of cognitve gap: Mental Mental development by wealth quintiles at birth in development by wealth quintiles at birth in 1,579 children in rural Bangladesh
-0.8
-0.6
-0.4
-0.2
-0
0.2
0.4
0.6
0.8
7 18 63 Age in Months
Z scores
Hamadani unpublished
Problem BayleySolving MDI
WPPSI IQ
Timing: Effect of 1 z-score of birth weight & growth in length on IQ at 5 years, controlling for SES
(n=1579)
0
0.05
0.1
0.15
0.2
Birthweight
Growth 0-24m
Growth24-64m
Hamadani Tofail unpublished MINIMat
**p<0.01 *p<0.05
IQ Z scores
*
**
*
*
Timing: Effect of preschool on IQ at 5 years, (controlling for SES, nutritional status and Bayley scores at 18 months)
(n=1579)
0
0.1
0.2
0.3
0.4
0.5
Kindergarten Non-formal
Primary school
Hamadani, Tofail unpublished
IQ Z scores
Growth 24-64
Maktab
***88***
**
** *
**p<0.01* p<0.05
Urgent need to prevent enormous wastage Urgent need to prevent enormous wastage in individual and national developmentin individual and national development
Well evaluated projects Well evaluated projects at scaleat scale with long with long term follow upterm follow up
Explore ways of Explore ways of integratingintegrating stimulation stimulation with other services for<3yearswith other services for<3years
Implications for Future Policy
health and nutrition services.health and nutrition services.
• cash transfer/ women’s groups/ faith cash transfer/ women’s groups/ faith groups/microcredit groupsgroups/microcredit groups
• Upgrade preschoolsUpgrade preschools
Implications for Future Policy
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