Composição nutricional do leite humano e sua correlação com variáveis maternas: estudo prospectivo

• Autor(a) principal: Costa, André Gustavo Vasconcelos
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/2713
• topic: Leite humano; Composição; Ácidos graxos; Amamentação; Mulheres; Consumo alimentar; Breast milk; Composition; Fatty acids; Breast-feeding; Women; Food consumption; CNPQ::CIENCIAS DA SAUDE::NUTRICAO::DIETETICA

Due to its biological superiority, the lipid fraction of human milk is especially important to newborns. However, the lipid fraction can be affected by factors associated to the mother s and the newborn s health and nutritional conditions. This prospective study analyzed the fatty acid (FA) percentage, total lipids (TL), and the energy of the human milk of 33 mothers of the city of Viçosa MG, Brazil; during three months of lactation (median periods of 1, 7, 32, 62, and 91 days after delivery). The behavior of these parameters was correlated to the following variables: period of lactation, education level, newborn s weight at birth, newborn s weight gain, type of delivery, parity, maternal ethnicity, gestational age, and maternal food consumption. The latter was evaluated through 24-Hour Dietary Recall (R24H) at 7, 32, 62, and 91 days after delivery; Questionnaire of Frequency of Food Consumption (QFFC), and Food Availability List (FAL) applied during the 91 days after delivery. The women studied had low income (R$ 652.00 ± R$ 367.00) and low level of education (8.8 ± 2.5 years of study). In relation to the breast-feeding period, we found less significant differences (p < 0.001) for C10:0 and C14:0 for the 1-day period in relation to the other periods. C16:0 was significantly smaller (p = 0.03) for the 32-day than for the 1-day period and C16:1 presented lower percentage for the 1-day period in relation to those of the other periods (p = 0.01). The n-6:n-3 and the total de novo synthesis (C10:0. C12:0 and C14:0) ratio throughout the study period were 10 to 14 and 5.6 17.9 mg%, respectively. The percent TL and energy were significantly smaller (p = 0.03 each) for the 1-day period in relation to the 32- and 91-day periods. Of the total human milk samples collected (n = 156), one showed strong correlations (p < 0.001) between C18:2n-6 and C18:3n-3 and the summation of n-3, polyunsaturated fatty acid (PUFA), and total FA. The same occurred for C18:3n-3 relative to the n-6 sum of total PUFA and FA. The education level, newborn s weight at delivery, type of delivery, parity, and gestational age did not affect the human milk parameters analyzed significantly. In relation to the newborn's weight gain, the general average of this parameter correlated inversely and significantly with the percentages of C12:0 (r = -0.468; p = 0.03), C14:0 (r = -0.062; p = <0.001), and saturated fatty acid (SFA) (r = -0.443; p = 0.02). Concerning maternal food consumption, it was not observed significant correlations between the parameters investigated for the average of the four R24H and the percent FA, TL, and the energy of human milk. In accordance with QFFC and FAL, the maternal consumption of cow whole milk correlated positively (p < 0.05) with total SFA, monounsaturated fatty acid (MUFA), PUFA, total FA and with the percentages of C18:2n-6 in human milk. Strong negative correlations were observed between the ingestion of pork and the percentages of C18:2n-6 (r = -0.630; p = -0.035). Although fish consumption was comparable to that of beef, it did not affect the human milk parameters studied. This study confirms that the lipid content of human milk can be affected by the lactation period and maternal diet. We believe that the other maternal and newborn variables tudied can contribute to the lipid composition of human milk. However, such effects have not been demonstrated in this study. These results evidenced that the daily consumption of cow whole milk led to positive alterations in the fatty acid profile of human milk, differently from the daily consumption of pork. The use of QFFC and FAL to evaluate habitual ingestion was more efficient in the analysis of the fatty acid profile of human milk than the average of the four R24H was. We point out that prospective studies that evaluate the evolution of the lipid composition of human milk throughout the initial periods of breast-feeding are scarce in the scientific literature.