O efeito tardio da prática da amamentação na densidade mineral óssea de mulheres na pós-menopausa: revisão sistemática de estudos observacionais

Abstract

Breastfeeding is a period of intense bone mobilization for milk production. During this phase, women suffer a great loss of bone mass with evidence of recovery after weaning. Currently this has been a worrying period in woman's life as there are suspicions that bone loss during lactation generates a late effect on bone mineral density (BMD) when this woman is postmenopausal. The reduced BMD is a major risk factor for osteoporosis that affects around 200 million women over fifty years worldwide. The aim of this study was to evaluate the effect of breastfeeding on bone mineral density in postmenopausal women. For this, we performed a systematic literature review. The search for articles in databases (Lilacs, Medline via Pubmed and Scopus) were supplemented by manual checking of references. It was identified a total of 181 articles and, after applying the inclusion criteria, 24 articles were selected for the systematic review. The results of several studies are divergent concerning methodological issues, classification of breastfeeding duration, for the variables that cause confusion, age group and ethnicity, which makes comparisons between them difficult. Part of the studies relates some kind of effect (positive or negative) while another part shows, the most frequently, the observation of an inverse correlation between breastfeeding and bone mineral density in postmenopausal. However, when other variables (number of pregnancies, age, time since menopause, etc.) are considered in the analysis in conjunction with breastfeeding, the latter loses significant relationship. More studies with better methodological rigor are still necessary to evaluate if indeed the effect can be attributed to breastfeeding or other factors that are also related to bone mineral density in postmenopausal women.