RESUMO
To determine whether breast-feeding is protective against infection in relatively affluent populations, morbidity data were collected by weekly monitoring during the first 2 years of life from matched cohorts of infants who were either breast fed (BF) (N = 46) or formula fed (FF) (N = 41) until at least 12 months of age. Cohorts were matched for characteristics such as birth weight and parental socioeconomic status, and we controlled for use of day care in data analysis. Mean maternal educational level was high (16 years) in both groups. In the first year of life the incidence of diarrheal illness among BF infants was half that of FF infants; the percentage with any otitis media was 19% lower and with prolonged episodes (> 10 days) was 80% lower in BF compared with FF infants. There were no significant differences in rates of respiratory illness; nearly all cases were mild upper respiratory infections. Morbidity rates did not differ significantly between groups in the second year of life, but the mean duration of episodes of otitis media was longer in FF than BF infants (8.8 +/- 5.3 vs 5.9 +/- 3.5 days, respectively; p = 0.01). These results indicate that the reduction in morbidity associated with breast-feeding is of sufficient magnitude to be of public health significance.
Assuntos
Alimentação com Mamadeira , Aleitamento Materno , Alimentos Infantis , Adulto , Creches , Pré-Escolar , Estudos de Coortes , Diarreia Infantil/epidemiologia , Diarreia Infantil/etiologia , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Morbidade , Análise Multivariada , Otite Média/epidemiologia , Otite Média/etiologia , Prevalência , Doenças Respiratórias/epidemiologia , Doenças Respiratórias/etiologiaRESUMO
We compared growth, dietary intake, and morbidity of infants breast-fed for > or = 12 mo from two populations: Davis, CA (n = 46) and Huascar, Peru (n = 52). When compared against WHO reference data (based primarily on formula-fed infants), Huascar infants appeared to falter as early as 3-4 mo, but when compared with Davis breast-fed infants, the curves for weight and length were very similar in girls until 10-12 mo and in boys until 6-9 mo. Thereafter, Huascar infants grew less rapidly than did Davis infants. Breast milk intake was very similar between groups, but in Huascar the amount and nutrient density of complementary foods consumed after 6 mo were lower and morbidity rates were much higher than in Davis. These results indicate that growth faltering of Huascar infants, when judged against breast-fed infants in the United States, occurs primarily after the first 6 mo of life and is not due to poor lactation performance.
Assuntos
Aleitamento Materno , Alimentos Infantis , Animais , Estatura , Peso Corporal , Ingestão de Alimentos , Ingestão de Energia , Feminino , Humanos , Lactente , Masculino , Leite Humano , Peru , Pobreza , Estados UnidosRESUMO
Breast-fed infants grow less rapidly after the first 2 to 3 months of age than current standards. The DARLING study (Davis Area Research on Lactation, Infant Nutrition and Growth) was designed to evaluate whether this pattern should be considered "faltering" or is a normal outcome even under optimal conditions. Data on intake, growth, morbidity, activity, and motor development were collected longitudinally from infants who were breast fed for at least 12 months. Gross energy intake, calculated from 4-day records of milk and food intake at 3, 6, 9, and 12 months, averaged 91.4, 84.1, 86.7, and 91.8 kcal/kg per day, respectively, well below recommended amounts of metabolizable energy. Nevertheless, infants usually left some food unconsumed. Growth velocity was also below current reference data and was weakly correlated with energy intake. There were no significant negative associations between energy intake at any time and incidence, prevalence, or duration of any category of morbidity during the subsequent 3 months. There were no consistent associations between energy intake and activity level, time spent sleeping, or achievement of key developmental milestones. Similarly, infants with slower growth velocity were just as active and were ill no more often in subsequent months than infants who were growing more rapidly. Thus the deviation from current recommendations for energy intake and growth can be considered a normal pattern with no apparent deleterious consequences in our population of breast-fed infants.