Correlation between infant mortality in the Europe of nineteenth-century and malnutrition. An overview of selenium and seleno-enzymes: The last novelties about their role in human health and a focus on SelR (MsrB1)

Child malnutrition in sub-Saharan Africa is still a very high mortality factor that now is unacceptable in the common thinking of the Western country’s citizens. The situation was not always this way: in fact, in nineteenth-century Europe, infant mortality was two orders of magnitude higher than actual Europe and one higher than present-day Africa. This issue was linked to the poor and incorrect nutrition to which children were subjected from birth and their mothers during pregnancy and breastfeeding, making infant mortality a very frequent e dramatic phenomenon. Medical research did not yet know the good nutritional rules, and chemistry research had not yet identified vitamins and micronutrients that today allow maintaining good health and higher life expectancy. Among the latest micronutrients identified and widely studied, there is selenium, a trace mineral present in the soil, that is essential for humans in small amounts which, through refined processes of cellular biosynthesis, becomes part of some proteins in the form of very reactive seleno-cysteine instead of classical cysteine. These proteins, called indeed seleno-proteins, are essential for the execution of many metabolic pathways relevant for life.