Componentes oxidantes e antioxidantes do leite materno: associação com o nível de estresse no pós-parto

Abstract

Breast milk contains a complex combination of nutrients, immunological and hormonal factors, and components such as oxidants and antioxidants. Postpartum stress can alter this oxidant/antioxidant balance, increasing free radical levels and decreasing the availability of antioxidants in breast milk, affecting its composition. When this balance is altered, oxidative stress can occur. It can occur as a result of the psychological and physical stress of the puerperal woman during the period of postpartum changes in diet and lifestyle. Adequate maternal nutritional status is ideal for preventing the growth and development of the baby, as well as for preventing maternal overweight and obesity. Thus, the objective of this study is to evaluate the oxidant and antioxidant capacity of breast milk from nursing mothers and its relationship with nutritional status. This is a cross-sectional quantitative study conducted with women from the immediate postpartum period (24h to 48h postpartum) up to six months of the newborn's birth in a maternity hospital of the Unified Health System. The inclusion criteria were women with a singleton pregnancy, negative serology for syphilis and HIV during pregnancy, non-user of illicit drugs, absence of comorbidities and/or any other condition that would prevent breastfeeding, birth in a maternity hospital of the Unified Health System and absence of malformation in the newborn. Women who were unable to obtain colostrum and/or who needed continuous use of any medication by the puerperal woman were excluded. The Body Mass Index (BMI) was used to classify the anthropometric nutritional status. The results were obtained through the collection of colostrum and mature breast milk from 74 women. The differences in the mean of Thiobarbituric Acid - TBARS were greater both in the analysis between groups (F(1,70)= 5.87; p= 0.018) and within group (F(1,70)= 5.04; p= 0.028), with its concentration being higher in the mature milk of overweight women when compared to eutrophic women. Both markers, Non-protein Thiols-NPHS and Protein Thiols-PSH, showed significant differences when compared between groups (F(1,70)= 4.50; p= 0.037; F(1,70)= 5.29; p= 0.024), respectively. Higher concentrations were observed in the colostrum of nursing mothers with adequate weight, as well as in the mature milk of those with high weight in the concentrations of the antioxidant NPHS (F(1,70)= 5.20; p= 0.026) and PSH (F(1,70)= 4.91; p= 0.030). Thus, it is concluded that the effect of the nutritional status of nursing mothers alters the oxidant and antioxidant markers present in breast milk and its significant relationship between nutritional status and the milk phase.