The purpose of this study was to investigate the trans fatty acids (TFA) content and distribution in colostrum, mature milk, and diet of adolescent mothers, after TFA declaration in food labels became mandatory in Brazil. Participants were healthy adolescents (n 54, 15-19 years, 1-90 days postpartum) practicing exclusive breastfeeding. Milk samples were collected 3 days after delivery (colostrum) and in the third month postpartum (mature milk) by hand expression. The fatty acid composition of the milk samples was determined by gas chromatography. TFA intake corresponded to 1.23 % of total energy value. Total 18:2 TFA accounted for less than 0.5 % of the energy intake. The amount of total 18:1 TFA (mean ± SEM) was 1.9 % ± 0.14 in colostrum and 1.5 % ± 0.2 in mature milk. The total content of n-3 PUFA was inversely correlated with the total content of 18:1 TFA in colostrum. Both in colostrum and in mature milk, vaccenic acid (11t-18:1) was found to be the most abundant 18:1 trans isomer, followed by elaidic acid (9t-18:1), whereas rumenic acid (9c,11t-18:2 CLA) was the predominant 18:2 trans isomer. In conclusion, the levels of TFA of industrial sources found in the mother's diet and breast milk (colostrum and mature milk) showed a decrease in relation to those observed in studies conducted prior to the TFA labeling resolution in Brazil. However, the current low intake levels of n-3 LCPUFA and DHA content in the milk of lactating adolescents may be insufficient for supporting adequate neurological development of the infants.

A prática da amamentação tem grande impacto do ponto de vista da saúde pública, pois o leite materno é o melhor alimento a ser oferecido até o sexto mês de vida da criança. A fração lipídica do leite representa a maior fonte de energia para crianças e fornece nutrientes essenciais, tais como vitaminas lipossolúveis e ácidos graxos poliinsaturados (AGPI). Os ácidos graxos essenciais (AGE) linoléico (LA, 18:2n-6) e alfa-linolênico (ALA, 18:3n-3) são precursores dos ácidos graxos poliinsaturados de cadeia longa (AGPI-CL), incluindo os ácidos docosahexaenóico (DHA) e araquidônico (ARA). A qualidade dos lipídios no leite secretado está diretamente relacionada com a ingestão materna. Os AGPI-CL são importantes na proteção contra alergia e infecções, no processo visual e no desenvolvimento cognitivo na infância. O processamento industrial de alimentos introduziu os ácidos graxos trans (AGT) entre os nutrientes disponíveis à população. Os AGT podem interferir no metabolismo dos AGE, diminuindo a síntese de DHA e ARA. Portanto, nos parece relevante esclarecer a população sobre a importância de um aporte adequado de AGPI e reduzido de AGT durante o período de desenvolvimento pré e pós-natal.

Adolescence is marked by intensive growth and development. When pregnancy occurs during this period of the mother's growth, there is an increase in her nutritional needs. The aim of this study was to determine the levels of calcium, iron, copper, and zinc in maternal plasma, the placenta, and in the cord plasma of pregnant teenagers and adults. A total of 80 sets of maternal plasma, placentas, and cord plasma (40 from teenagers and 40 from adults) were analyzed using synchrotron radiation total reflection X-ray fluorescence. The levels of calcium, copper, and zinc in the maternal and cord plasma from teenagers were not significantly different than those from adults. Iron levels in the teenagers maternal and cord plasma were higher than in the adults. All of the minerals analyzed were present at higher levels in the placentas from adults than those from teenagers. However, the low quantities of placental calcium, iron, copper, and zinc in the teenagers do not compromise the levels of these minerals in the cord plasma. Future research regarding the placental transport of these minerals is recommended to investigate the efficiency of mechanisms of transfer of these minerals in pregnant teenagers.

The placenta is fundamental for fetal development. The aim of this study was to determine Ca, Fe, Cu, and Zn content in the fetal and maternal portions of the placentas of teenage and adult women. Measurement of the minerals was conducted using Synchrotron radiation total reflection X-ray fluorescence. Forty samples from the fetal portion of teenagers and adults and 40 samples from the maternal portion of teenagers and adults were analyzed. There were significant differences in the Ca and Cu concentrations of the placenta's maternal portion when compared to the fetal portion, for both teenagers and adults. There were differences in Fe and Zn concentrations only when comparing the maternal portion of placenta with the fetal portion of the adults. These results suggest important differences in mineral content based on the placental portion. No significant difference was observed between the minerals studied of the maternal portion of teenagers and adults; however, in the fetal portion, mineral concentrations were greater in adults than in teenagers. Therefore, the mineral concentration of the fetal portion of the placenta is influenced by the mother's age. If there is mineral's competition between the mother and fetus during pregnancy in adolescence due to the importance of these minerals in growth and development, then the mechanism and reason for it should be elucidated in future research. In addition, we believe that further research should be carried out on transporters of these minerals in the same portions of the placentas analyzed by our group, in teenagers and adults.

No abstract

Aim: To evaluate the energy content of milk of nursing mothers of premature infants and identify whether there is association with caloric intake and maternal sociodemographic variables. Methods: analytical, cross-sectional study with milk donated by 18 nursing mothers of premature infants admitted to the Neonatal Intensive Care Unit of the National Institute of Woman, Child and Adolescent Health - IFF/Fiocruz. The energy content of breast milk was evaluated by crematocrit, by the human milk bank. To assess maternal food consumption, the Food Frequency Questionnaire was used and sociodemographic data were obtained from interviews with the nursing mothers. Data were evaluated using the SPSS 22.0 software.Results: It was found that 89% of the milk collected was normocaloric, with an average energy content of 597.2 ± 79.1 kcal/L and that most of the milk expressed was colostrum. The average caloric intake of the nursing mothers was 2554 ± 413.1 kcal/day and the consumption of polyunsaturated fats, which corresponded to 3.5% of the total energy intake, was below the recommendation. There was no association between the energy content of human milk and the studied variables, but there was a tendency for nursing mothers living outside the city of Rio de Janeiro to have a higher caloric content in milk (p = 0.06).Conclusion: The human milk samples were normocaloric, maternal food consumption was inadequate for polyunsaturated fats and there was no association of sociodemographic variables or maternal caloric intake with the energy content of human milk.

The purpose of this study was to determine the levels of trans-octadecenoic acid (C18:1-trans) and trans-isomers of linoleic acid (18:2-trans), as well as long-chain polyunsaturated fatty acids (LC-PUFA), in the plasma from infants of adolescent mothers at 3 months of age, exclusively breastfed, and the relationship with the levels of the same isomers in plasma and milk of the mothers. Samples of blood and mature milk were obtained from 49 healthy adolescent mothers and their exclusively breastfed infants treated at the Instituto Fernandes Figueira-Fundação Oswaldo Cruz (IFF-FIOCRUZ) in Rio de Janeiro, Brazil. trans-Fatty acids (TFA) were analyzed by gas chromatography. The results of this study showed low levels of TFA in milk (1.53%), maternal plasma (0.50%), and plasma of infants (0.74%). The results show that, although TFA have been found in the plasma of the studied infants, the LC-PUFA levels are kept within normal limits. No association between TFA presence and parameters of nutritional status of the infants was observed, probably due to the low levels of these fatty acids found in this study.