Nutrition and early learning Aryeh D Stein, PhD Emory University Early Learning: Status and The Way Forward New Delhi, India September 25-27, 2013

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

vision of child development Every child is unique Children should develop according to their potential Adequate, nutritious food Safe, healthy environment High-quality cognitive stimulation Emotional support

Growth and Growth failure

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 population Growth 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

Measuring child nutrition 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

Growth failure happens early in life… Victora et al, Pediatrics 2010

Most growth failure has happened by age 24 mo Stein et al., Am J Hum Biol 2010 (updated)

Patterns of growth and growth failure Stein et al., Am J Hum Biol 2010 (updated)

Conclusions about growth Growth failure happens early in life Populations 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

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

And more broadly, per 1 HAZ at age 2 y… 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 Hoddinott et al., AJCN 2013

Child growth and cognitive achievement at age 8y Crookston et al., AJCN in press

Stunting and cognitive achievement at 8 y Crookston et al., AJCN in press

Conclusions about growth and cognitive functioning and schooling 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

What is the role of nutrition in the association between growth patterns and cognitive outcomes?

Nutrition, Growth, Cognition Cognitive achievements Food ECCD / Schooling

Do nutrition interventions make a difference?

INCAP nutrition trial follow-up

Intakes in children 15-36 mo Intervention design 2 larger villages 2 smaller villages Atole Fresco Atole Fresco Intakes in children 15-36 mo Atole Fresco Ingredients (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 PROTEIN ENERGY INTAKE FROM SUPPLEMENT INTAKE FROM DIET

Yes, for growth Severe stunting (%) Severe stunting = HAZ <-3.0 at age 3 y Habicht and Martorell J Nutr 2010

Yes, for Schooling Girls: 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

Yes, for Income and productivity Wages 34% to 46% higher Annual hours worked 222 Lower (CI: -572 to 128) Annual income US$ 914 higher (CI: -$190, $2018) Hoddinott et al. Lancet 2008.

Conclusions about nutrition interventions 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.

Which nutrition interventions? WHAT? WHY? WHO?

What? - What should be the focus? Food Prepared meals Nutrient supplements Single nutrients Multiple micronutrients Other factors Animal-source foods Dietary fats DHA Energy Carbohydrates Added sugars Zinc Vitamin A Calcium B group vitamins Iron Diet overall

WHY? - What is the objective? Improve growth Improve micronutrient status Improve physiologic parameters Immune function Oxidative stress Encourage participation in ECCD or schooling activities

WHO? - Who should be the focus? Pregnant and lactating women Infants (6 mo - 2 /3 y) Preschool children (3-6 y) Elementary school children (6-11 y) Adolescents (12 +) Working adults Elderly

Discussion and recommendations 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 impacts Food as a participation incentive may be a useful adjunct to a high-quality educational program Food 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

Rates of return to investments in human potential Heckman, Science 2006

Acknowledgements Funding for research: Other: US National Institutes of Health Wellcome Trust Bill and Melinda Gates Foundation Other: CARE-India, CARE-USA Colleagues and study participants

Thank you