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Background: Zinc deficiency is thought to be common in young children in developing countries and some data suggest that it may detrimentally affect children's development., Objective: Our goal was to assess the effect of zinc supplementation on the developmental levels and behavior of Bangladeshi infants., Design: This was a randomized, double-blind, controlled trial conducted in Dhaka, Bangladesh. Three hundred one infants aged 1 mo were randomly assigned to receive either 5 mg elemental Zn or placebo daily for 5 mo, and subsequent growth and morbidity were observed. For the present study, developmental levels were assessed in a subsample of 212 infants at 7 and 13 mo of age with use of the Bayley Scales of Infant Development, and the infants' behavior during the tests was observed. The children's social backgrounds, weights, and lengths were also recorded., Results: The children's nutritional status was generally poor. The zinc-treated group had slightly lower scores on the mental development index of the Bayley Scales than did the placebo group (beta = 3.7, SE = 1.3, P < 0.005). This effect remained significant when nutritional status and social background were controlled for. No other significant differences between groups were noted., Conclusions: The mental development index scores of the zinc-treated group were slightly but significantly lower than those of the placebo group. This finding may have been due to micronutrient imbalance. Caution should be exercised when supplementing undernourished infants with a single micronutrient.

Hunger during school may prevent children in developing countries from benefiting from education. Although many countries have implemented school feeding programs, few programs have been rigorously evaluated. We conducted a randomized, controlled trial of giving breakfast to undernourished and adequately nourished children. The undernourished group comprised 407 children in grades 2-5 in 16 rural Jamaican schools (weights-for-age < or = -1 SD of the National Center for Health Statistics references) and the adequately nourished group comprised 407 children matched for school and class (weights-for-age >-1 SD). Both groups were stratified by class and school, then randomly assigned to breakfast or control groups. After the initial measurements, breakfast was provided every school day for 1 school year. Children in the control group were given one-quarter of an orange and the same amount of attention as children in the breakfast group. All children had their heights and weights measured and were given the Wide Range Achievement Test before and after the intervention. School attendance was taken from the schools' registers. Compared with the control group, height, weight, and attendance improved significantly in the breakfast group. Both groups made poor progress in Wide Range Achievement Test scores. Younger children in the breakfast group improved in arithmetic. There was no effect of nutritional group on the response to breakfast. In conclusion, the provision of a school breakfast produced small benefits in children's nutritional status, school attendance, and achievement. Greater improvements may occur in more undernourished populations; however, the massive problem of poor achievement levels requires integrated programs including health and educational inputs as well as school meals.

Background: Approximately 39% of children aged <5 y in developing countries are growth retarded (stunted) and many have poor mental development and behavioral abnormalities. Animal research suggests that an altered stress response may contribute to the negative outcomes following undernutrition., Objective: We tested the hypothesis that stunted children have higher salivary cortisol concentrations and heart rates and altered behavior when compared with nonstunted children when social background was controlled for., Design: We compared 30 stunted with 24 nonstunted children, all of whom were 8-10 y old and lived in the same poor areas of Kingston, Jamaica. All subjects were participants in a prospective, longitudinal, case-control study of children who were stunted in early childhood. We administered a test session (including psychologic and physical stressors), measured baseline and response levels of salivary cortisol and heart rate, and observed behavior., Results: Compared with nonstunted children, stunted children had higher salivary cortisol concentrations (P = 0.007), had higher heart rates during the psychologic test session (P = 0.03), exhibited enhanced cardiovascular responsivity to a physical stressor (P = 0.04), vocalized less, were more inhibited, and were less attentive. After birth weight or social background and maternal and child intelligence quotients were controlled for, the differences in cortisol concentration and cardiovascular reactivity remained significant., Conclusions: Our findings suggest that consistent growth retardation since early childhood affects physiologic arousal, which, we speculate, may contribute to the poor cognitive functioning and immune responses of stunted children and the relation between adult short stature and increased cardiovascular risk.

It is hypothesized that giving children a daily breakfast at school may improve their scholastic achievement through several mechanisms: increasing the time spent in school, improving certain cognitive functions and attention to tasks, and, perhaps indirectly, improving nutritional status. Two Jamaican studies showed that providing breakfast to students at school improved some cognitive functions, particularly in undernourished children. However, changes in classroom behavior varied depending on the quality of the school. Children in better-organized schools concentrated on tasks for longer periods and made fewer undesirable movements, whereas in poorly organized schools the children's behavior deteriorated. Studies to date have provided insufficient evidence to determine whether children's long-term scholastic achievement is improved by eating breakfast daily. Well-designed, randomized, controlled, long-term trials are essential for determining public policy on the implementation of school feeding programs.

It is not known whether nutritional supplementation in early childhood has long-term benefits on stunted children's mental development. We followed up 127 7-8-y old children who had been stunted in early childhood and received supplementation, stimulation, or both. At 9-24 mo of age, the children had been randomly assigned to four treatment groups: nutritional supplementation, stimulation, both treatments, and control. After 2 y, supplementation and stimulation had independent benefits on the children's development and the effects were additive. The group receiving both treatments caught up to a matched group of 32 nonstunted children. Four years after the end of the 2-y intervention 97% of the children were given a battery of cognitive function, school achievement, and fine motor tests. An additional 52 nonstunted children were included. Factor analyses of the test scores produced three factors: general cognitive, perceptual-motor, and memory. One, the perceptual-motor factor, showed a significant benefit from stimulation, and supplementation benefited only those children whose mothers had higher verbal intelligence quotients. However, each intervention group had higher scores than the control subjects on more tests than would be expected by chance (supplemented and both groups on 14 of 15 tests, P = 0.002; stimulated group in 13 of 15 tests, P = 0.01), suggesting a very small global benefit. There was no longer an additive effect of combined treatments at the end of the intervention. The stunted control group had significantly lower scores than the nonstunted children on most tests. Stunted children's heights and head circumferences on enrollment significantly predicted intelligence quotient at follow-up.

A method is presented to estimate a cutoff for hemoglobin concentration appropriate for estimating the prevalence of iron deficiency anemia in poor Jamaican girls 13-14 y of age. Iron deficiency was determined from a three-variable model of iron status (serum ferritin, erythrocyte protoporphyrin, and mean corpuscular volume). The most appropriate hemoglobin cutoff was considered the one that minimized misclassification of iron deficiency: that yielding the maximum kappa coefficient for correctly classifying iron deficiency between 100 and 120 g/L, at 1-g/L intervals. By using this method, a hemoglobin cutoff of 107 g/L was considered most appropriate. This cutoff and the other indicators were used to estimate prevalence of iron deficiency and iron deficiency anemia in the Jamaican girls: 7.6% and 4.3%, respectively. This approach should be appropriate for determining hemoglobin cutoffs for iron deficiency anemia in other populations.

Methodological issues and problems in studies of the effects of protein-energy malnutrition (PEM) and child development are discussed with reference to our experience in Jamaica. The usefulness of defining PEM by stunting, wasting, and edema is stressed. Difficulties in achieving reliable and valid measurements of mental development and behavior in Third World children, and allowing for the confounding and possibly interacting effects of social background, are discussed. Problems associated with different approaches are outlined.

An individual's behavior is created by an amalgam of genetic, environmental, cultural, and historical variables working in concert and changing over time. Variations in nutrition are one class of environmental factors. Linking these to outcome effects requires carefully designed studies. Many considerations are involved, and this paper draws attention to some of the fundamental ones. Psychological and behavioral functions tend to be complex, in part because they are affected by a wide range of variables. Almost any given state--a particular constellation of psychological characteristics displayed by an individual at a given time--can be produced in a variety of ways.

Children aged 9-24 mo were recruited by a survey of poor areas of Kingston, Jamaica. Stunted children were randomly assigned to supplementation or not. Weekly morbidity histories were taken for 2 y. Separate multiple regressions on each symptom for weight or length gain in 2-mo intervals showed significant reductions in weight gain with coughing, apathy, anorexia, diarrhea, and fever, ranging from -2.1 to -16.8 g/d ill. Apathy and diarrhea reduced gains in length (-0.26 and -0.20 mm/d ill). Significant reductions in linear growth with lower respiratory-tract infections (-0.16 mm/d ill) occurred only in nonsupplemented children. Growth over 4-mo intervals was reduced if diarrhea occurred in the first 2 mo of the interval but there were no long-term effects of apathy, fever, or anorexia. Some of the effects of morbidity on growth were therefore transient and morbidity is unlikely to be a major cause of growth retardation in this population.

The benefits of nutritional supplementation, with or without psychosocial stimulation, on the growth of stunted children were evaluated. Children aged 9-24 mo with lengths less than -2 SD of the National Center for Health Statistics references (n = 129) were randomly assigned to four groups: control, nutritional supplementation, stimulation, and both interventions. A fifth group with lengths greater than -1 SD was also enrolled. Length, weight, head and arm circumferences, and triceps and subscapular skinfold thicknesses were measured on enrollment and 6 and 12 mo later. Multiple-regression analysis was used to determine the effects of the interventions in which age, sex, initial status, initial dietary intake, and several socioeconomic variables were controlled for. Stimulation had no effect on growth and there was no interaction between the interventions. After 12 mo supplemented children had significantly increased length, weight, and head circumference (all P less than 0.01). The effects of supplementation were not cumulative but occurred in the first 6 mo.

A survey of two poor neighborhoods in Kingston, Jamaica is reported. The nutritional status in children under 48 months (309) and the developmental levels of children between six and thirty months (168) were assessed. Characteristics of children with poor nutritional status and development were identified. Thirty-one percent of the children had Gomez grade 1 malnutrition, 9% had Gomez grade 2, and 1.6% had Gomez grade 3. There was somewhat more stunting than wasting. Nutritional indicators, weight for age and weight for height, as well as developmental levels declined with the children's age. Children with poor nutritional status tended to be girls, have poor housing, mothers with low levels of education, and mothers who worked. Children with low developmental quotients (DQs) tended to be boys and have mothers who worked. Multiple regression analysis showed that stunting (ht/age) and weight for age had significant effects on DQ, whereas wasting (wt/ht) did not.

We examined the effects of omitting breakfast on the cognitive functions of three groups of children: stunted, nonstunted controls, and previously severely malnourished. They were admitted to a metabolic ward twice. After an overnight fast half the children received breakfast on their first visit and a cup of tea the second time. The treatment order was reversed for the other half. When breakfast was omitted, both the stunted and previously malnourished groups responded similarly. The malnourished groups had lower scores in fluency and coding whereas the control group had higher scores in arithmetic. The children were divided into wasted and nonwasted groups. Wasted children were adversely affected in the digit span backwards tests, and wasted members of the malnourished groups were adversely affected in efficiency of problem solving and those in the control group in digit span forwards. These results indicate that cognitive functions are more vulnerable to missing breakfast in poorly nourished children.