RESUMO
OBJECTIVE: The US Dietary Guidelines for Americans recommends increased consumption of the dairy group to three daily servings for ages 9+ years to help achieve adequate intakes of prominent shortfall nutrients. Identifying affordable, consumer-acceptable foods to replace dairy's shortfall nutrients is important especially for people who avoid dairy. DESIGN: Linear programming identified food combinations to replace dairy's protein and shortfall nutrients. We examined cost, energy and dietary implications of replacing dairy with food combinations optimised for lowest cost, fewest kJ or the smallest amount of food by weight. SETTING: National Health and Nutrition Examination Survey (2011-2014). PARTICIPANTS: Nationally representative sample of US population; 2 years and older (n 15 830). RESULTS: Phase 1 (only dairy foods excluded): when optimised for lowest cost or fewest kJ, all non-dairy food replacements required large amounts (2·5-10 cups) of bottled/tap water. Phase 2 (dairy and unreasonable non-dairy foods excluded (e.g. baby foods; tap/bottled water): when intake of non-dairy foods was constrained to <90th percentile of current intake, the lowest cost food combination replacements for dairy cost 0·5 times more and provide 5·7 times more energy; the lowest energy food combinations cost 5·9 times more, provide 2·5 times more energy and require twice the amount of food by weight; and food combinations providing the smallest amount of food by weight cost 3·5 times more and provide five times more energy than dairy. CONCLUSIONS: Identifying affordable, consumer-acceptable foods that can replace dairy's shortfall nutrients at both current and recommended dairy intakes remains a challenge.
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Ingestão de Energia , Alimentos , Criança , Dieta , Humanos , Nutrientes , Inquéritos Nutricionais , Estados UnidosRESUMO
BACKGROUND: A large portion of Americans are not meeting the Dietary Reference Intakes (DRI) for several essential vitamins and minerals due to poor dietary choices. Dairy products are a key source of many of the nutrients that are under consumed, but children and adults do not consume the recommended amounts from this food group. This study modeled the impact of meeting daily recommended amounts of dairy products on population-based nutrient intakes. METHODS: Two-day 24-h dietary recalls collected from participants ≥ 2 years (n = 8944) from the 2007-2010 What We Eat in America, National Health and Nutrition Examination Survey (NHANES) were analyzed. Databases available from the WWEIA/NHANES and the United States Department of Agriculture (USDA) were used to determine nutrient, food group, and dietary supplement intakes. Modeling was performed by adding the necessary number of dairy servings, using the dairy composite designed by USDA, to each participant's diet to meet the dairy recommendations outlined by the 2010 Dietary Guidelines for Americans. All analyses included sample weights to account for the NHANES survey design. RESULTS: The majority of children 4 years and older (67.4-88.8%) and nearly all adults (99.0-99.6%) fall below the recommended 2.5-3 daily servings of dairy products. Increasing dairy consumption to recommended amounts would result in a significant reduction in the percent of adults with calcium, magnesium, and vitamin A intakes below the Estimated Average Requirement (EAR) when considering food intake alone (0-2.0 vs. 9.9-91.1%; 17.3-75.0 vs. 44.7-88.5%; 0.1-15.1 vs. 15.3-48.0%, respectively), as well as food and dietary supplement intake. Minimal, but significant, improvements were observed for the percent of people below the EAR for vitamin D (91.7-99.9 vs. 91.8-99.9%), and little change was achieved for the large percentage of people below the Adequate Intake for potassium. CONCLUSIONS: Increasing dairy food consumption to recommended amounts is one practical dietary change that could significantly improve the population's adequacy for certain vitamins and minerals that are currently under-consumed, as well as have a positive impact on health.
Assuntos
Laticínios , Dieta , Micronutrientes/deficiência , Inquéritos Nutricionais , Recomendações Nutricionais , Adolescente , Adulto , Idoso , Cálcio da Dieta/administração & dosagem , Criança , Pré-Escolar , Suplementos Nutricionais , Feminino , Humanos , Magnésio/administração & dosagem , Masculino , Rememoração Mental , Micronutrientes/administração & dosagem , Pessoa de Meia-Idade , Potássio/administração & dosagem , Estados Unidos , Vitamina A/administração & dosagem , Vitamina D/administração & dosagem , Adulto JovemRESUMO
Two complementary studies focused on stability of infant temperament across the 1st year and considered infant age, gender, birth order, term status, and socioeconomic status (SES) as moderators. Study 1 consisted of 73 mothers of firstborn term girls and boys queried at 2, 5, and 13 months of age. Study 2 consisted of 335 mothers of infants of different gender, birth order, term status, and SES queried at 6 and 12 months. Consistent positive and negative affectivity factors emerged at all time points across both studies. Infant temperament proved stable and robust across gender, birth order, term status, and SES. Stability coefficients for temperament factors and scales were medium to large for shorter (< 9 months) interassessment intervals and small to medium for longer (> 10 months) intervals.
Assuntos
Ordem de Nascimento , Desenvolvimento Infantil/fisiologia , Idade Gestacional , Classe Social , Temperamento/fisiologia , Feminino , Humanos , Lactente , Masculino , Fatores SexuaisRESUMO
BACKGROUND: The risk of chronic disease cannot be predicted simply by the content of a single nutrient in a food or food group in the diet. The contribution of food sources of calories, added sugars and saturated fat (SFA) to intakes of dietary fiber and micronutrients of public health importance is also relevant to understanding the overall dietary impact of these foods. OBJECTIVE: Identify the top food sources of calories, added sugars and SFA in the U.S. diet and quantify their contribution to fiber and micronutrient intakes. METHODS: Single 24-hour dietary recalls (Day 1) collected from participants ≥2 years (n = 16,822) of the What We Eat in America, National Health and Nutrition Examination Survey (WWEIA/NHANES 2003-2006) were analyzed. All analyses included sample weights to account for the survey design. Calorie and nutrient intakes from foods included contributions from disaggregated food mixtures and tabulated by rank order. RESULTS: No one food category contributes more than 7.2% of calories to the overall U.S. diet, but half of the top 10 contribute 10% or more of total dietary fiber and micronutrients. Three of the top 10 sources of calories and SFA (beef, milk and cheese) contribute 46.3% of the calcium, 49.5% of the vitamin D, 42.3% of the vitamin B12 as well as other essential nutrients to the American diet. On the other hand, foods categorized as desserts, snacks, or beverages, contribute 13.6% of total calories, 83% of added sugar intake, and provide little or no nutritional value. Including food components of disaggregated recipes more accurately estimated the contribution of foods like beef, milk or cheese to overall nutrient intake compared to "as consumed" food categorizations. CONCLUSIONS: Some food sources of calories, added sugars and SFA make major contributions to American dietary fiber and micronutrient intakes. Dietary modifications targeting reductions in calories, added sugar, or SFA need to take these key micronutrient sources into account so as not to have the unintended consequence of lowering overall dietary quality.
Assuntos
Carboidratos/administração & dosagem , Dieta Ocidental , Ingestão de Energia , Ácidos Graxos/administração & dosagem , Comportamento Alimentar , Inquéritos Nutricionais , Bebidas , Laticínios , Fibras na Dieta/administração & dosagem , Humanos , Micronutrientes/administração & dosagem , Valor Nutritivo , Estados UnidosRESUMO
Milk proteins are known for their high nutritional quality, based on their essential amino acid composition, and they exhibit a wide range of bioactivities, including satiety, antimicrobial, mineral-binding, and anti-lipidemic properties. Because of their unique water solubility, milk proteins are readily separated into casein and whey fractions, which can be further fractionated into many individual proteins, including alpha-S1- and alpha-S2-caseins, beta-casein, and kappa-casein, and the whey proteins alpha-lactalbumin, lactoferrin, beta-lactoglobulin, and glycomacropeptide. Many of these proteins have unique bioactivities. Further, over the past 30 years, peptides that are encrypted in the primary amino acid sequences of proteins and released along with amino acids during digestion are increasingly recognized as biologically active protein metabolites that may have beneficial effects on human health. This review examines the current state of the science on the contribution of dairy proteins and their unique peptides and amino acids to human health.
Assuntos
Caseínas , Lactalbumina , Aminoácidos , Humanos , Proteínas do Leite/química , Peptídeos , Proteínas do Soro do LeiteRESUMO
The concept of sustainable diets, although not new, is gaining increased attention across the globe, especially in relation to projected population growth and growing concerns about climate change. As defined by the FAO (Proceedings of the International Scientific Symposium, Biodiversity and Sustainable Diets 2010; FAO 2012), "Sustainable diets are those diets with low environmental impacts which contribute to food and nutrition security and to healthy life for present and future generations." Consistent and credible science that brings together agriculture, food systems, nutrition, public health, environment, economics, culture, and trade is needed to identify synergies and trade-offs and to inform guidance on vital elements of healthy, sustainable diets. The aim of this article is to review the emerging research on environmental and related economic impacts of dietary patterns, including habitual eating patterns, nutritionally balanced diets, and a variety of different dietary scenarios. Approaches to research designs, methodologies, and data sources are compared and contrasted to identify research gaps and future research needs. To date, it is difficult to assimilate all of the disparate approaches, and more concerted efforts for multidisciplinary studies are needed.
Assuntos
Agricultura , Comércio , Conservação dos Recursos Naturais , Dieta , Comportamento Alimentar , Abastecimento de Alimentos , Ciências da Nutrição , Agricultura/economia , Cultura , Dieta/economia , Abastecimento de Alimentos/economia , Humanos , Saúde PúblicaRESUMO
Economic growth in developing countries and globalization of the food sector is leading to increasingly similar food consumption patterns worldwide. The aim of this study was to describe similarities and differences in the contributions of main food groups to energy and nutrient intakes in five developed countries across three continents. We obtained summary reports of national food consumption survey data from Australia, France, Denmark, the Netherlands, and the United States. Survey years spanned 2003-2012; sample size ranged from 1444 to 17,386. To mitigate heterogeneity of food groups across countries, we recategorized each survey's reported food groups and subgroups into eight main food groups and, for three countries, a ninth "mixed dishes" group. We determined the percent contribution of each food group to mean daily intakes of energy, saturated fat, sodium, fiber, and ten vitamins and minerals that are commonly under-consumed. Differences in findings from surveys utilizing a foods-as-consumed versus a disaggregated or ingredients approach to food group composition and contributions from the milk and milk products group, a source of several under-consumed nutrients, were explored. Patterns of food group contributions to energy and nutrient intakes were generally similar across countries. Some differences were attributable to the analytical approach used by the surveys. For the meat/protein, milk and milk products, vegetables, and fruit groups, percent contributions to key nutrient intakes exceeded percent contributions to energy intake. The mixed dishes group provided 10%-20% of total daily energy and a similar 10%-25% of the daily intake of several nutrients. This descriptive study contributes to an understanding of food group consumption patterns in developed countries.
Assuntos
Dieta , Ingestão de Energia , Adolescente , Adulto , Idoso , Animais , Austrália , Criança , Pré-Escolar , Dinamarca , Países Desenvolvidos , Comportamento Alimentar , França , Frutas , Humanos , Rememoração Mental , Pessoa de Meia-Idade , Leite , Países Baixos , Inquéritos Nutricionais , Oligoelementos/administração & dosagem , Estados Unidos , Verduras , Vitaminas/administração & dosagem , Adulto JovemRESUMO
OBJECTIVE: Glutamine (Gln) is a non-essential amino acid that plays an important role in energy metabolism for gastrointestinal epithelia and other cells with rapid turnover. We evaluated the effects of enteral supplementation with Gln in infants undergoing surgery for congenital or acquired gastrointestinal disease. METHODS: This was a randomized, double-masked, controlled clinical trial. RESULTS: Twenty infants were randomly assigned to receive Gln (n = 9) or placebo amino acid (n = 11), with a goal of supplemental amino acid intake of 0.4 g.kg(-1).d(-1). Infants were weaned from parenteral nutrition, and enteral feeds were started according to a standardized feeding protocol. Median (interquartile range) durations of parenteral nutrition were 39 d (12 to 99) in the Gln group and 21 d (6 to 59) in the control group (P = 0.201). Median (interquartile range) durations needed to reach 80% of the US recommended dietary allowance for energy with enteral nutrition were 24 d (8 to 55) in the Gln group and 12.5 d (5 to 32) in the control group (P = 0.313). There were no differences in the occurrence of infections between groups. Among all infants enrolled, significant correlations were found between duration of parenteral nutrition and residual small bowel length, peak concentrations of direct bilirubin, and alanine aminotransferase. Peak direct bilirubin was associated with longer duration of parenteral nutrition, shorter gestation, older age before feeds were started, shorter bowel length, and larger amounts of parenteral energy and protein intake. CONCLUSIONS: In this pilot trial, enteral Gln supplementation was well tolerated among infants with surgical gastrointestinal disease. There was no effect observed on the duration of parenteral nutrition, tolerance of enteral feeds, or intestinal absorptive or barrier function. Larger, multicenter trials in infants with surgical gastrointestinal disease are needed due to the variability in important outcome measurements.
Assuntos
Suplementos Nutricionais , Gastroenteropatias/cirurgia , Glutamina/uso terapêutico , Método Duplo-Cego , Nutrição Enteral/métodos , Feminino , Glutamina/administração & dosagem , Humanos , Recém-Nascido , Absorção Intestinal/efeitos dos fármacos , Masculino , Nutrição Parenteral/métodos , Projetos Piloto , Período Pós-Operatório , Fatores de Tempo , Resultado do Tratamento , Aumento de Peso/efeitos dos fármacosRESUMO
Human milk provides small quantities of preformed docosahexaenoic acid (DHA) and arachidonic acid (ARA), usually less than 1% of total fatty acids. Vegetable oil blends commonly used in infant formulas have, until recently, provided the essential fatty acid precursors for these long-chain polyunsaturated fatty acids (LCPUFA), but no preformed DHA and ARA. This study evaluated the safety of ingredient sources of DHA and ARA for use in infant formulas in a neonatal piglet model. Newborn piglets were allowed to suckle for 3 days and then divided into 4 feeding groups of 6 males and 6 females. Piglets were bottle-fed at frequent feeding intervals until 19 days of age. The composition of the piglet formulas was modeled after standard milk-based formulas for human infants while meeting nutritional requirements for piglets. Formulas were a control formula (no added DHA or ARA), a DHA formula providing 55 mg DHA/100 Cal, an ARA formula providing 96 mg/100 Cal ARA, and a DHA+ARA formula providing 34 mg DHA and 62 mg ARA/100 Cal. All formulas were equal in fat content and provided approximately 1000 Cal/l. The ARA-rich oil was from a fermentation product of Mortierella alpina (40 wt.% fatty acids as ARA) and DHA was from high DHA tuna oil (25 wt.% fatty acids as DHA). There were no test article related effects of DHA and/or ARA indicative of an adverse health consequence to the animals seen in the clinical signs, body weights, food consumption, clinical chemistry, hematology, organ weights or gross or histopathology. The findings in this neonatal animal study support the safety of these ingredient oil sources of DHA and ARA for use in infant formulas.
Assuntos
Ácido Araquidônico/toxicidade , Ácidos Docosa-Hexaenoicos/toxicidade , Alimentos Infantis , Animais , Animais Recém-Nascidos , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Estudos de Avaliação como Assunto , Ácidos Graxos/sangue , Feminino , Humanos , Lactente , Masculino , Tamanho do Órgão/efeitos dos fármacos , Segurança , SuínosRESUMO
Because dairy products provide shortfall nutrients (eg, calcium, potassium, and vitamin D) and other important nutrients, this study hypothesized that it would be difficult for Americans to meet nutritional requirements for these nutrients in the absence of dairy product consumption or when recommended nondairy calcium sources are consumed. To test this hypothesis, MyPyramid dietary pattern modeling exercises and an analyses of data from the National Health and Nutrition Examination Survey 2003-2006 were conducted in those aged at least 2 years (n = 16 822). Impact of adding or removing 1 serving of dairy, removing all dairy, and replacing dairy with nondairy calcium sources was evaluated. Dietary pattern modeling indicated that at least 3 servings of dairy foods are needed to help individuals meet recommendations for nutrients, such as calcium and magnesium, and 4 servings may be needed to help some groups meet potassium recommendations. A calcium-equivalent serving of dairy requires 1.1 servings of fortified soy beverage, 0.6 serving of fortified orange juice, 1.2 servings of bony fish, or 2.2 servings of leafy greens. The replacement of dairy with calcium-equivalent foods alters the overall nutritional profile of the diet and affects nutrients including protein, potassium, magnesium, phosphorus, riboflavin, vitamins A, D and B(12). Similar modeling exercises using consumption data from the National Health and Nutrition Examination Survey also demonstrated that nondairy calcium replacement foods are not a nutritionally equivalent substitute for dairy products. In conclusion, although it is possible to meet calcium intake recommendations without consuming dairy foods, calcium replacement foods are not a nutritionally equivalent substitute for dairy foods and consumption of a calcium-equivalent amount of some nondairy foods is unrealistic.
Assuntos
Laticínios , Dieta/efeitos adversos , Comportamento Alimentar , Modelos Biológicos , Adolescente , Adulto , Idoso , Cálcio da Dieta/administração & dosagem , Criança , Pré-Escolar , Laticínios/análise , Feminino , Promoção da Saúde , Humanos , Masculino , Desnutrição/prevenção & controle , Política Nutricional , Inquéritos Nutricionais , Valor Nutritivo , Potássio na Dieta/administração & dosagem , Estados Unidos , Vitamina D/administração & dosagemRESUMO
The objective of this study was to evaluate growth and body composition of premature infants who were fed formulas with arachidonic acid (ARA; 20:4n6) and docosahexaenoic acid (DHA; 22:6n3) to 1 y of gestation-corrected age (CA). Preterm infants (750-1800 g birth weight and <33 wk gestational age) were assigned within 72 h of first enteral feeding to one of three formulas: control (n = 22), DHA+ARA from fish/fungal oil [DHA+ARA(FF); n = 20], or DHA+ARA from egg/fish oil [DHA+ARA(EF); n = 18]. Human milk feeding was allowed on the basis of the mother's choice. Infants were fed breast milk and/or preterm formulas with or without 0.26% DHA and 0.42% ARA to term CA followed by breast milk or postdischarge preterm formulas with or without 0.16% DHA and 0.42% ARA to 12 mo CA. Body composition was measured by dual-energy x-ray absorptiometry. There were no significant differences among the three study groups at any time point in weight, length, or head circumference. Bone mineral content and bone mineral density did not differ among groups. At 12 mo CA, infants who were fed DHA+ARA-supplemented formulas had significantly greater lean body mass (p < 0.05) and significantly less fat mass (p < 0.05) than infants who were fed the unsupplemented control formula. The DHA+ARA-supplemented formulas supported normal growth and bone mineralization in premature infants who were born at <33 wk gestation. Preterm formulas that had DHA+ARA at the levels and ratios in this study and were fed to 1 y CA led to increased lean body mass and reduced fat mass by 1 y of age.
Assuntos
Composição Corporal , Ácidos Graxos Insaturados/metabolismo , Alimentos Fortificados , Recém-Nascido Prematuro , Absorciometria de Fóton , Fatores Etários , Ácido Araquidônico/farmacologia , Peso ao Nascer , Estatura , Peso Corporal , Densidade Óssea , Ácidos Docosa-Hexaenoicos/farmacologia , Método Duplo-Cego , Ácidos Graxos/sangue , Ácidos Graxos/metabolismo , Feminino , Humanos , Fórmulas Infantis , Recém-Nascido , Masculino , Leite Humano/metabolismo , Fatores de TempoRESUMO
UNLABELLED: Previous studies found that juvenile offspring of rats fed high docosahexaenoic acid (DHA; 22:6n-3) diets through gestation and lactation had longer auditory brainstem-evoked response (ABR) accompanied by higher 22:6n-3 and lower arachidonic acid (ARA; 20:4n-6) in brain. In the present study, ABR was assessed in juvenile rats fed high-DHA diets only postnatally. METHODS: Rat pups were fed rat milk formulas with varying amounts of DHA and ARA to 19 days of age followed by diets with the corresponding fatty acids. The high-DHA group was fed 2.3% of fatty acids as DHA, the DHA + ARA group was fed DHA and ARA at 0.6 and 0.4% of fatty acids, levels similar to those in some infant formulas, and the unsupplemented group was fed no DHA or ARA. ABR and fatty acid and monoamine levels in brain were measured on postnatal days 26-28. Statistical analyses were measured by ANOVA. RESULTS: ARA and DHA levels in brain increased with supplementation. ABR was shorter in the high-DHA group than the DHA + ARA group and not different from the unsupplemented or dam-reared suckling group. Norepinephrine levels in the inferior colliculus were lower in the high-DHA group than the DHA + ARA group and higher in all formula groups compared to the dam-reared group. CONCLUSION: In contrast to the longer ABR in juvenile offspring of rats fed high-DHA through gestation and lactation, ABR was shorter in juvenile rats fed high-DHA diets only after birth than rats fed ARA + DHA. Further studies are needed to understand the relationship between dietary DHA, norepinephrine, and auditory system development over a range of DHA intakes and discrete periods of development.
Assuntos
Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácidos Docosa-Hexaenoicos/análise , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Alimentos Formulados/análise , Leite , Animais , Ácido Araquidônico/administração & dosagem , Ácido Araquidônico/análise , Monoaminas Biogênicas/análise , Encéfalo/crescimento & desenvolvimento , Química Encefálica , Ácidos Graxos/análise , Colículos Inferiores/química , Tamanho do Órgão , Fosfolipídeos/análise , Ratos , Ratos Sprague-Dawley , Aumento de PesoRESUMO
BACKGROUND: In a recent meta-analysis, human milk feeding of low birth-weight (LBW) infants was associated with a 5.2 point improvement in IQ tests. However, in the studies in this meta-analysis, feeding regimens were used (unfortified human milk, term formula) that no longer represent recommended practice. OBJECTIVE: To compare the growth, in-hospital feeding tolerance, morbidity, and development (cognitive, motor, visual, and language) of LBW infants fed different amounts of human milk until term chronologic age (CA) with those of LBW infants fed nutrient-enriched formulas from first enteral feeding. METHODS: The data in this study were collected in a previous randomized controlled trial assessing the benefit of supplementing nutrient-enriched formulas for LBW infants with arachidonic acid and docosahexaenoic acid. Infants (n = 463, birth weight, 750-1,800 g) were enrolled from nurseries located in Chile, the United Kingdom, and the United States. If human milk was fed before hospital discharge, it was fortified (3,050-3,300 kJ/L, 22-24 kcal/oz). As infants were weaned from human milk, they were fed nutrient-enriched formula with or without arachidonic and docosahexaenoic acids (3,300 kJ/L before term, 3,050 kJ/L thereafter) until 12 months CA. Formula fed infants were given nutrient-enriched formula with or without added arachidonic and docosahexaenoic acids (3,300 kJ/L to term, 3,050 kJ/L thereafter) until 12 months CA. For the purposes of this evaluation, infants were categorized into four mutually exclusive feeding groups: 1) predominantly human milk fed until term CA (PHM-T, n = 43); 2) >/= 50% energy from human milk before hospital discharge (>/= 50% HM, n = 98); 3) < 50% of energy from human milk before hospital discharge (< 50% HM, n = 203); or 4) predominantly formula fed until term CA (PFF-T, n = 119). RESULTS: PFF-T infants weighed approximately 500 g more at term CA than did PHM-T infants. This absolute difference persisted until 6 months CA. PFF-T infants were also longer (1.0-1.5 cm) and had larger head circumferences (0.3-1.1 cm) than both PHM-T and >/= 50% HM infants at term CA. There was a positive association between duration of human milk feeding and the Bayley Mental Index at 12 months CA (P = 0.032 full and P = 0.073 reduced, statistical models) after controlling for the confounding variables of home environment and maternal intelligence. Infants with chronic lung disease fed >/= 50% HM until term CA (n = 22) had a mean Bayley Motor Index about 11 points higher at 12 months CA compared with infants PFF-T (n = 24, P = 0.033 full model). CONCLUSION: Our data suggest that, despite a slower early growth rate, human milk fed LBW infants have development at least comparable to that of infants fed nutrient-enriched formula. Exploratory analysis suggests that some subgroups of human milk fed LBW infants may have enhanced development, although this needs to be confirmed in future studies.
Assuntos
Fórmulas Infantis , Fenômenos Fisiológicos da Nutrição do Lactente , Recém-Nascido Prematuro/crescimento & desenvolvimento , Leite Humano , Adulto , Cognição , Etnicidade , Feminino , Hospitalização , Humanos , Recém-Nascido , Desenvolvimento da Linguagem , Masculino , Idade Materna , Destreza Motora , Fatores de Tempo , Acuidade VisualRESUMO
OBJECTIVE: Docosahexaenoic acid (DHA) and arachidonic acid (ARA) are long-chain polyunsaturated fatty acids found in breast milk and recently added to infant formulas. Their importance in infant nutrition was recognized by the rapid accretion of these fatty acids in the brain during the first postnatal year, reports of enhanced intellectual development in breastfed children, and recognition of the physiologic importance of DHA in visual and neural systems from studies in animal models. These considerations led to clinical trials to evaluate whether infant formulas that are supplemented with DHA or both DHA and ARA would enhance visual and cognitive development or whether conversion of linoleic acid and alpha-linolenic acid, the essential fatty acid precursors of ARA and DHA, respectively, at the levels found in infant formulas is sufficient to support adequately visual and cognitive development. Visual and cognitive development were not different with supplementation in some studies, whereas other studies reported benefits of adding DHA or both DHA and ARA to formula. One of the first trials with term infants that were fed formula supplemented with DHA or both DHA and ARA evaluated growth, visual acuity (Visual Evoked Potential; Acuity Card Procedure), mental and motor development (Bayley Scales of Infant Development), and early language development (MacArthur Communicative Developmental Inventories). Growth, visual acuity, and mental and motor development were not different among the 3 formula groups or between the breastfed and formula-fed infants in the first year of life. At 14 months of age, infants who were fed the formula with DHA but no ARA had lower vocabulary production and comprehension scores than infants who were fed the unsupplemented control formula or who were breastfed, respectively. The present follow-up study evaluated IQ, receptive and expressive vocabulary, visual-motor function, and visual acuity of children from the original trial when they reached 39 months of age. METHODS: Infants were randomized within 1 week after birth and fed a control formula (n = 65), one containing DHA (n = 65), or one containing both ARA and DHA (n = 66) to 1 year of age. A comparison group (n = 80) was exclusively breastfed for at least 3 months after which the infants continued to be exclusively breastfed or were supplemented with and/or weaned to infant formula. At 39 months, standard tests of IQ (Stanford Binet IQ), receptive vocabulary (Peabody Picture Vocabulary Test-Revised), expressive vocabulary (mean length of utterance), visual-motor function (Beery Visual-Motor Index), and visual acuity (Acuity Card Procedure) were administered. Growth, red blood cell fatty acid levels, and morbidity also were evaluated. RESULTS: Results were analyzed using analysis of variance or linear regression models. The regression model for IQ, receptive and expressive language, and the visual-motor index controlled for site, birth weight, sex, maternal education, maternal age, and the child's age at testing. The regression model for visual acuity controlled for site only. A variable selection model also identified which of 22 potentially prognostic variables among different categories (feeding groups, the child and family demographics, indicators of illness since birth, and environment) were most influential for IQ and expressive vocabulary. A total of 157 (80%) of the 197 infants studied at 12 months participated in this follow-up study. Characteristics of the families were representative of US families with children up to 5 years of age, and there were no differences in the demographic or family characteristics among the randomized formula groups. As expected, the formula and breastfed groups differed in ethnicity, marital status, parental education, and the prevalence of smoking. Sex, ethnicity, gestational age at birth, and birth weight for those who participated at 39 months did not differ from those who did not. The 12-month Bayley mental and motor scores and 14-month vocabulary scores of the children who participated also were were not different from those who did not. At 39 months, IQ, receptive and expressive language, visual-motor function, and visual acuity were not different among the 3 randomized formula groups or between the breastfed and formula groups. The adjusted means for the control, ARA+DHA, DHA, and breastfed groups were as follows: IQ scores, 104, 101, 100, 106; Peabody Picture Vocabulary Test, 99.2, 97.2, 95.1, 97.4; mean length of utterance, 3.64, 3.75, 3.93, 4.08; the visual-motor index, 2.26, 2.24, 2.05, 2.40; and visual acuity (cycles/degree), 30.4, 27.9, 27.5, 28.6, respectively. IQ was positively associated with female sex and maternal education and negatively associated with the number of siblings and exposure to cigarette smoking in utero and/or postnatally. Expressive language also was positively associated with maternal education and negatively associated with the average hours in child care per week and hospitalizations since birth but only when the breastfed group was included in the analysis. The associations between maternal education and child IQ scores are consistent with previous reports as are the associations between prenatal exposure to cigarette smoke and IQ and early language development. Approximately one third of the variance for IQ was explained by sex, maternal education, the number of siblings, and exposure to cigarette smoke. Growth achievement, red blood cell fatty acid levels, and morbidity did not differ among groups. CONCLUSIONS: We reported previously that infants who were fed an unsupplemented formula or one with DHA or with both DHA and ARA through 12 months or were breastfed showed no differences in mental and motor development, but those who were fed DHA without ARA had lower vocabulary scores on a standardized, parent-report instrument at 14 months of age when compared with infants who were fed the unsupplemented formula or who were breastfed. When the infants were reassessed at 39 months using age-appropriate tests of receptive and expressive language as well as IQ, visual-motor function and visual acuity, no differences among the formula groups or between the formula and breastfed groups were found. The 14-month observation thus may have been a transient effect of DHA (without ARA) supplementation on early vocabulary development or may have occurred by chance. The absence of differences in growth achievement adds to the evidence that DHA with or without ARA supports normal growth in full-term infants. In conclusion, adding both DHA and ARA when supplementing infant formulas with long-chain polyunsaturated fatty acids supports visual and cognitive development through 39 months.