Nutrition and early learning Aryeh D Stein, PhD Emory University

Early Learning: Status and The Way Forward

New Delhi, India

September 25-27, 2013

NUTRITION AND EARLY LEARNING

Aryeh D Stein, PhDEmory University

Why focus on early nutrition?Does early nutrition matter for education?How much of a difference can we make?Recommendations

OVERVIEW

Every child is uniqueChildren should develop according to their

potential Adequate, nutritious food Safe, healthy environment High-quality cognitive stimulation Emotional support

VISION OF CHILD DEVELOPMENT

GROWTH AND GROWTH FAILURE

Growth happens when (and only when) food is not limiting

An individual child’s potential for growth is unknowable Growth failure can only be measured in terms of a reference

populationGrowth failure results from deficits in one or more

critical nutrients Energy-providing (fat, carbohydrate) Substrates (protein, calcium, fat) Metabolically-important micronutrients (iron, zinc, B

vitamins)Rate-limiting nutrient not always obvious

More of the wrong nutrient(s) will not solve the underlying cause

GROWTH AND GROWTH FAILURE

Establishing individual nutritional need is challenging

Nutritional status is snapshot Height / length for age Weight for height Micronutrient status

But it is a lagging indicator of the balance between intake and need

MEASURING CHILD NUTRITION

GROWTH FAILURE HAPPENS EARLY IN LIFE…

Victora et al, Pediatrics 2010

MOST GROWTH FAILURE HAS HAPPENED BY AGE 24 MO

Height at 24mo (m)

Growth 24mo - adult

(m)

Height at 24mo (f)

Growth 24mo - adult (f)

70.0

75.0

80.0

85.0

90.0 Brazil GuatemalaIndia PhilippinesSouth Africa Reference

cm

Stein et al., Am J Hum Biol 2010 (updated)

PATTERNS OF GROWTH AND GROWTH FAILURE

Stein et al., Am J Hum Biol 2010 (updated)

Birth 12 mo

24 mo

Mid-C

Adulthood

-3.5-3

-2.5-2

-1.5-1

-0.50

BrazilGuatemalaIndiaPhilippinesSouth Africa

HAZ

Growth failure happens early in lifePopulations that are short by age 2 remain

short as adult (but in absolute terms they do not fall much further behind)

There is some evidence of ‘catch-up’ in HAZ at a population level This is at least in part a methodological artifact

CONCLUSIONS ABOUT GROWTH

CHILD AGE AND BRAIN DEVELOPMENT

HUMAN BRAIN DEVELOPMENT

Grantham-McGregor et al., Lancet 2007

GROWTH FAILURE AND HUMAN CAPITAL

SCHOOLING PER SD OF HEIGHT AT 2Y

Victora et al, Lancet 2008

Cognitive: Schooling – 0.8 grades more

(mean of 4.7!) 0.25 SD increase in reading

comprehension 0.25 SD increase in non-

verbal comprehension (Raven’s)

Marriage and fertility: Partner 1.4 y older, 1.0 y

more schooling, 1.0 cm taller

Age at first birth 0.8 y later; 0.63 fewer pregnancies; 0.43 fewer children (women)

Economics: 20.9% increase in

household expenditures

10.1 pp decrease in prevalence of living in poverty

Health: 5% increase in grip

strength No association with

overweight/obesity, BP, glucose

AND MORE BROADLY, PER 1 HAZ AT AGE 2 Y…

Hoddinott et al., AJCN 2013

ET IN PE VN ET IN PE VN ET IN PE VN0

0.020.040.060.080.1

0.120.140.16

Length at 1yGrowth 1-8 y

Effec

t si

ze

Math Reading Vocabulary

CHILD GROWTH AND COGNITIVE ACHIEVEMENT AT AGE 8Y

Crookston et al., AJCN in press

ET IN PE VN ET IN PE VN ET IN PE VN-0.5

-0.4

-0.3

-0.2

-0.1

0

0.1

Persistently stunted Recovered FalteredEffec

t si

ze r

elat

ive

to n

ever

st

unte

d

Math Reading Vocabulary

STUNTING AND COGNITIVE ACHIEVEMENT AT 8 Y

Crookston et al., AJCN in press

Children who experience growth faltering stay in school fewer years, perform less well on standardized tests, and have diminished life prospects

Growth recovery after early childhood associated with partial recovery of cognitive function

CONCLUSIONS ABOUT GROWTH AND COGNITIVE FUNCTIONING AND SCHOOLING

WHAT IS THE ROLE OF NUTRITION IN THE ASSOCIATION BETWEEN

GROWTH PATTERNS AND COGNITIVE OUTCOMES?

NUTRITION, GROWTH, COGNITION

Cognitive achievement

s

GrowthFood

ECCD / Schoolin

g

DO NUTRITION INTERVENTIONS

MAKE A DIFFERENCE?

INCAP NUTRITION TRIAL FOLLOW-UP

INTERVENTION DESIGN

Atole FrescoIngredients (g/180 ml)

Incaparina 13.5 -

Dry skim milk

21.6 -

Sugar 9.0 13.3

Flavoring agent

- 2.1

Nutrients per 180 ml

Energy (kcal) 163 59

Protein (g) 11.5 -

2 smaller villages

Atole Fresco

19 21

011

751 785

153 25

0

5

10

15

20

25

30

Atole Fresco Atole Fresco

g / d

ay

0100200300400500600700800900

kcal

/day

PROTEIN ENERGY

INTAKE FROM DIET

INTAKE FROM

SUPPLEMENT

Intakes in children 15-36 mo

2 larger villages

Atole Fresco

0

10

20

30

40

50

1969 1970-71 1972-73 1974-75 1976-77

Atole (n=451) Fresco (n=429)

YES, FOR GROWTHSe

vere

stu

ntin

g (%

)

Severe stunting = HAZ <-3.0 at age 3 y Habicht and Martorell J Nutr 2010

YES, FOR SCHOOLINGGirls: 1.17 grades Boys: No impact on schooling attainment

“The intervention had the effect of promoting greater equality of schooling attainment between women and men, compared to their parents, as it was more effective in the subpopulation (i.e., women) with lower previous schooling.”

Maluccio et al, Econ J, 2009

YES, FOR INTELLECTUAL CAPACITY

Stein et al., APAM 2009

Hoddinott et al. Lancet 2008.

Wages34% to 46% higher

Annual hours worked222 Lower

(CI: -572 to 128)Annual income

US$ 914 higher (CI: -$190, $2018)

0-24 0-36 36-720.00

0.15

0.30

0.45

0.60

0.750.67000000

00000020.620000000000002

0.22

Window of exposure (months)

US$

/ hr

YES, FOR INCOME AND PRODUCTIVITY

P < 0.01

P < 0.01

P > 0.4

In at least one context, supplementation of pregnant women and young children with a nutritious complementary food made a substantial difference in the growth, schooling, cognitive functioning, and economic productivity of the children as adults.

As with all randomized trials, generalization to other contexts must be considered carefully.

CONCLUSIONS ABOUT NUTRITION INTERVENTIONS

WHAT?WHY?WHO?

WHICH NUTRITION INTERVENTIONS?

FoodPrepared mealsNutrient

supplementsSingle nutrientsMultiple micronutrients

WHAT? - WHAT SHOULD BE THE FOCUS?

Diet overall

Zinc

Dietary fats

B group vitamin

s

Vitamin A

Calcium

DHA

Iron

CarbohydratesAdded

sugars

Energy

Other factors

Animal-source foods

Improve growthImprove micronutrient statusImprove physiologic parameters

Immune function Oxidative stress

Encourage participation in ECCD or schooling activities

WHY? - WHAT IS THE OBJECTIVE?

Pregnant and lactating womenInfants (6 mo - 2 /3 y)Preschool children (3-6 y)Elementary school children (6-11 y)Adolescents (12 +)Working adultsElderly

WHO? - WHO SHOULD BE THE FOCUS?

Nutrition for prevention has to happen early in life, the earlier the better First 1000 days

High-quality food in sufficient quantities to meet energy needs will also meet needs for all micronutrients Single-nutrient interventions are unlikely to have

generalizable impactsFood as a participation incentive may be a useful

adjunct to a high-quality educational programFood is not a panacea

Cognitive development requires cognitive stimulation Good nutrition can increase the efficiency of good teaching Macronutrient / micronutrient density Risk for overweight/obesity

DISCUSSION AND RECOMMENDATIONS

RATES OF RETURN TO INVESTMENTS IN HUMAN POTENTIAL

Heckman, Science 2006

Funding for research: US National Institutes of Health Wellcome Trust Bill and Melinda Gates Foundation

Other: CARE-India, CARE-USA Colleagues and study participants

ACKNOWLEDGEMENTS

THANK YOU