Daniza Ivanovic

Head size and intelligence, learning, nutritional status and brain development Head, IQ, learning, nutrition and brain

This multifactorial study investigates the interrelationships between head circumference (HC) and intellectual quotient (IQ), learning, nutritional status and brain development in Chilean school-age children graduating from high school, of both sexes and with high and low IQ and socio-economic strata (SES). The sample consisted of 96 right-handed healthy students (mean age 18.0 +/- 0.9 years) born at term. HC was measured both in the children and their parents and was expressed as Z-score (Z-HC). In children, IQ was determined by means of the Wechsler Intelligence Scale for Adults-Revised (WAIS-R), scholastic achievement (SA) through the standard Spanish language and mathematics tests and the academic aptitude test (AAT) score, nutritional status was assessed through anthropometric indicators, brain development was determined by magnetic resonance imaging (MRI) and SES applying the Graffar modified method. Results showed that microcephalic children (Z-HC < or = 2 S.D.) had significantly lower values mainly for brain volume (BV), parental Z-HC, IQ, SA, AAT, birth length (BL) and a significantly higher incidence of undernutrition in the first year of life compared with their macrocephalic peers (Z-HC > 2S.D.). Multiple regression analysis revealed that BV, parental Z-HC and BL were the independent variables with the greatest explanatory power for childs Z-HC variance (r(2) = 0.727). These findings confirm the hypothesis formulated in this study: (1) independently of age, sex and SES, brain parameters, parental HC and prenatal nutritional indicators are the most important independent variables that determine HC and (2) microcephalic children present multiple disorders not only related to BV but also to IQ, SA and nutritional background.

Long-term effects of severe undernutrition during the first year of life on brain development and learning in Chilean high-school graduates.

The objective of this study was to assess the relative impact of undernutrition during the first year of life on brain development, intellectual quotient (IQ), and scholastic achievement (SA) of poor Chilean high-school graduates (mean age = 18.3 +/- 0.9 y). A comparative study of two groups of high-school graduates from a low socioeconomic stratum was carried out. The undernourished group (n = 16), who had suffered from severe undernutrition during the first year of life, was compared with the non-undernourished group (n = 16). The final sample consisted of 32 right-handed high-school graduate students born at term who had no history of alcoholism or symptoms of brain damage, epilepsy, or heart disease and whose mothers had no history of smoking, alcoholism, or drug intake before and during pregnancy. Socioeconomic status was measured by using Graffars modified method. Birth weight was used as the prenatal nutritional status index, and postnatal nutritional status was assessed by the body mass index, Z score for head circumference, and brachial anthropometry. IQ was determined with the Wechsler Intelligence Scale for Adults, and SA was determined with test in language and mathematics with the academic aptitude test. Brain development was evaluated by magnetic resonance imaging. Statistical analysis included variance tests, Scheffes test for comparison of means, correlation, and multiple regression. Maternal schooling, brain volume, and undernutrition were the independent variables, with the greatest explanatory power in IQ variance (r(2) = 0.714). Only IQ explained SA variance (r(2) = 0.860); IQ, corpus callosum length, anteroposterior diameter, and maternal schooling were the independent variables, with the greatest explanatory power in the academic aptitude test variance (r(2) = 0.949). Results show that the long-term effects of malnutrition at an early age may affect brain development, IQ, and SA in school-age children. These findings are useful for nutrition and educational planning.

Nutritional status, brain development and scholastic achievement of Chilean high-school graduates from high and low intellectual quotient and socio-economic status

The objective of the present study was to investigate the inter-relationships between nutritional status (past and current nutrition), brain development, and scholastic achievement (SA) of Chilean high-school graduates from high and low intellectual quotient (IQ) and socio-economic status (SES) (mean age 18.0 (SD 0.9) years). Results showed that independently of SES, high-school graduates with similar IQ have similar nutritional, brain development and SA variables. Multiple regression analysis between child IQ (dependent variable) and age, sex, SES, brain volume (BV), undernutrition during the first year of life, paternal and maternal IQ (independent variables) revealed that maternal IQ (P<0.0001), BV (P<00387) and severe undernutrition during the first year of life (P<0.0486), were the independent variables with the greatest explanatory power for child IQ variance (r2 0.707), without interaction with age, sex or SES. Child IQ (P<0.0001) was the only independent variable that explained both SA variance (r2 0.848) and academic aptitude test variance (r2 0.876) without interaction with age, sex or SES. These results confirm the hypotheses formulated for this study that: (1) independently of SES, high-school graduates with similar IQ have similar variables of nutritional status, brain development and SA; (2) past nutritional status, brain development, child IQ and SA are strongly and significantly inter-related. These findings are relevant in explaining the complex interactions between variables that affect IQ and SA and can be useful for nutritional and educational planning.

Chemical and nutritional evaluation of sweet lupines.

Sweet lupines are presently being cultivated at the Experimental Station in Gorbea (Chile). Four cultivars, Lupinus albus cv Astra, L. albus cv Multolupa, Lupinus luteus cv Aurea and Lupinus angustifolius, were examined for the chemical composition of whole and dehulled seeds and testa. Whole seeds contain 34-35% protein. The varieties of L. albus contain 13% oil. L. luteus and L. angustifolius contain about 5% ether extract. Crude fiber ranged from 11 to 17% in the whole seed. Unsaturated fatty acids, especially oleic and linoleic, make up about 80% of total fatty acids. The alkaloid content of the seed was 0.02%. The amino acid composition of the protein indicated that the main deficiency corresponds to the sulfur-containing amino acids, i.e. methionine + cystine. The protein efficiency ratio values for L. albus cv Multolupa was 1.08 and 2.50 for casein. Supplementation with DL-methionine at 0.1, 0.2, 0.3 and 0.4% of the diet significantly increased the basal value from 1.08 to 2.14, for the supplemented diet with 0.1% (p less than 0.01). Higher levels of supplementation did not cause significant increases in the protein efficiency ratio. Apparent protein digestibility for the rat was 75% for unsupplemented lupine. This value increased to about 79% (p less than 0.01) for the supplemented diets (casein 88.7%).

Nutrition and Learning in Chilean School Age Children: Chile's Metropolitan Region Survey 1986-1987

The objective of this study was to determine the interrelationship between the scholastic achievement (SA) test and nutritional status of a representative sample of 4,509 elementary and high school children from Chiles Metropolitan Region. Percentages of weight/age (W/A), height/age (H/A), and weight/height (W/H) were compared to WHO (World Health Organization) Tables, head circumference/age (HC/A) to the Tanner Tables, and brachial anthropometry to Frisanchos norms. Socioeconomic status (SES) was measured by means of Graffars Modified Method; SA by means of a language and mathematics test. Statistical analysis included correlation, regression, and WHO risk-approach methodology. Results showed that HC/A was the anthropometric parameter with the greatest explanatory power in SA variance and was significantly greater in high school graduates who were 17 y old (r = 0.350; p < 0.001; r2 = 0.122) than in elementary school children, who were 6 y old (r = 0.227; p < 0.001; r2 = 0.049), with a relative risk of 2.1 and 1.5, respectively. The explanatory power of W/A and H/A in SA variance was significantly decreased, and no significant differences were observed among high school students. These findings confirm that HC/A is the most important anthropometric parameter associated with SA. Educational selectivity apparently relates to HC/A, and not to W/A or H/A. These results may be useful in planning nutritional and educational policies.

Intellectual ability and nutritional status assessed through anthropometric measurements of Chilean school-age children from different socioeconomic status.

This study was designed to investigate the interrelationships between intellectual ability (IA), nutritional status measured through anthropometric measurements and socio‐economic and socio‐cultural parameters. A representative sample of 4,509 school‐age children according to grade, sex, type of school and geographic area was chosen from Chiles Metropolitan Region. School‐age children 5 to 22 years of age belonged to elementary and high schools. The cross‐sectional research was carried out in 1986–1987. IA was measured by means of the Ravens Progressive Matrices Test. The Z‐scores for weight (Z‐W) and height (Z‐H) and the percentage of adequacy weight/height (% W/H), were compared with WHO tables; the Z‐scores for head circumference (Z‐HC) with Tanner tables and brachial anthropometric measurements with Frisancho standards. Socio‐economic status (SES) was determined using Graffars modified method. Statistical procedures included analysis of variance, Scheffes test for comparison of means, correlation and regression. IA positively and significantly correlated with Z‐HC, Z‐H, Z‐W and brachial anthropometric parameters; however, Z‐HC is the anthropometric index with the greatest explanatory power in IA variance, followed by Z‐H. Z‐HC increased its explanatory power in IA variance with age and in school‐age children 16 years of age or more this was the only anthropometric parameter that explained IA variance (F = 22.56, p < 0.0001; r2 = 0.142). Independent of SES and age, in the total sample, Z‐HC, sex, maternal and household head schooling, Z‐H, sewerage and quality of housing, were the independent variables with the greatest explanatory power in IA variance (F = 43.03, p < 0.0001, r 2 = 0.176), in males, (F = 22.04, p < 0.0001, r 2 = 0.159) and in females (F = 25.98, p < 0.0001, r 2 = 0.191), the only group in which Z‐H entered in the statistical model. Taking into consideration that HC is an indicator of nutritional background and brain development, these results may provide the basis for further research related with the impact of malnutrition at an earlier age on IA, HC and subsequent brain development and for improved nutritional and educational planning.

Nutritional status of Chilean school children from different socioeconomic status and sex. Chile's metropolitan region. Survey 1986–1987

The aim of this study was to assess the nutritional status of Chilean school children of different socioeconomic status (SES). A representative sample of 4,355 school children aged 5–18 years, from elementary and high school, was chosen from Chiles Metropolitan Region (representative of 38.0% of the Chilean school population), according to grade, type of school, sex and geographic area. SES was measured through Graffars Modified Method and nutritional status by means of anthropometry measurements. Percentages of adequacy of weight for age (% W/A), height for age (% H/A) and weight for height (% W/H) were compared with WHO tables. Median weights and heights of school children showed a nutritional status improvement in all age groups as compared with previous findings. On the other hand, overnutrition (% W/H) is now the most significant nutritional problem in all SES groups especially in females, suggesting that this problem must be prevented through primary health care nutrition programmes.

Twelve-year follow-up study of the impact of nutritional status at the onset of elementary school on later educational situation of Chilean school-age children

Objective:To determine the impact of nutritional status in a multicausal approach of socio-economic, socio-cultural, family, intellectual, educational and demographic variables at the onset of elementary school in 1987 on the educational situation of these children in 1998, when they should have graduated from high school.Setting:Chiles Metropolitan Region.Design:Prospective, observational and 12-year follow-up study.Methods:A representative sample of 813 elementary first grade school-age children was randomly chosen in 1987. The sample was assessed in two cross-sectional studies. The first cross-sectional study was carried out in at the onset of elementary school in 1987 and the second was carried out in 1998, 12-years later, when they should be graduating from high school. In 1998, 632 adolescent students were located and their educational situation was registered (dropout, delayed, graduated and not located). At the onset of elementary school were determined the nutritional status, socio-economic status (SES), family characteristics, intellectual ability (IA), scholastic achievement (SA) and demographic variables. Statistical analysis included variance tests and Scheffes test was used for comparison of means. Pearson correlation coefficients and logistic regression were used to establish the most important independent variables at the onset of elementary school in 1987 that affect the educational situation 1998. Data were analysed using the statistical analysis system (SAS).Results:Logistic regression revealed that SES, IA, SA and head circumference-for-age Z score at the onset of elementary school in 1987 were the independent variables with the greatest explanatory power in the educational situation of school-age children in 1998.Conclusions:These parameters at an early school age are good predictors of the educational situation later and these results can be useful for nutrition and educational planning in early childhood.Sponsorship:This study was supported in part by Grants 1841167 and 1880818 from the National Fund for Scientific and Technologic Development (FONDECYT), Grants S 2169-924F and EO11-97/2 from the University of Chile, Research Department (DI), and by Grant 019/1997 from the University of Chile, Postgradest Department.

Impact of nutritional status at the onset of elementary school on academic aptitude test achievement at the end of high school in a multicausal approach.

Like in many other countries, few investigations have been carried out in Chile to measure the long-term effects of nutritional status at an early age on scholastic achievement in a multicausal approach. The objectives of the present study were to describe the impact of nutritional, intellectual, family, educational and socio-economic variables at the onset of elementary school in 1987 that may affect achievement on the academic aptitude test (AAT) taken in 1998 at the end of high school, and to quantify the impact of these independent variables on the AAT. The present study comprises two cross-sectional stages: in 1987, a representative sample of 813 elementary school first-grader Chilean children from the Metropolitan Region was randomly chosen; in 1998, 12 years later, 632 school-age children were located and only 351 of them graduated from high school and, from these, 260 students took the AAT. In 1987 nutritional status was assessed through anthropometric parameters, intellectual ability by the Ravens Progressive Matrices Test, scholastic achievement through Spanish language and mathematics tests, and socio-economic status using Graffars modified scale; family variables were also recorded. Maternal schooling, scholastic achievement, intellectual ability and head circumference-for-age z-score (anthropometric indicator of both nutritional background and brain development) all in 1987 were the independent variables with the greatest explanatory power for AAT variance in 1998 (r2 0.402). These results provide a foundation to identify the risk factors at an early age that affect AAT scores and should be useful to improve nutritional and educational policies.

Physically active Chilean school kids perform better in language and mathematics

We examined the association between the engagement in regular physical activity (PA) and the academic performance (AP) of school-age children from Santiago Metropolitan Region. In a random sample of 1271 students (13.3 ± 2.3 years old) we measured regular PA, accounting for hours of weekly scheduled exercise, and AP, using national standardized tests scores in Language and Mathematics. Bivariate and multivariate regression analyses were used to model the relation between academic and health-related behaviors. Two outcomes were considered: (i) sufficiency according to the Ministry of Education and (ii) discretionary sufficiency (tests z-scores ≥50th percentile). About 80% of students were poorly engaged in scheduled exercise (<2 h per week). Devoting more than 4 h per week to scheduled exercise significantly increased the odds of reaching the official and discretionary sufficiency in both Language and Mathematics. Moderate engagement (2-4 h per week) just improved the odds of reaching the discretionary sufficiency standard. These results confirm the poor engagement in regular exercise at the school level. School kids with the highest allocation of time to scheduled exercise have better AP in Language and Mathematics. Our findings support the notion that academic and health-related behaviors are linked and, similarly, that school health programs may have positive effects on educational outcomes.