Metal concentrations in breastmilk of Fuzhou nursing mothers associates with dietary and lifestyle factors

Abstract

Metal intake greatly influences physiological development during infancy. For infants, breastmilk is the major route of metal exposure. The metal status of their nursing mothers is affected by lifestyle and nutritional factors. However, the relationship between these factors and breastmilk metal concentration is largely unknown. The present study provided food frequency questionnaires to be completed by 113 nursing mothers from Fujian Provincial Hospital. Their breastmilk samples were analysed for the metal concentrations using inductively coupled plasma mass spectrometery (ICP-MS). Based on the outcome of the questionnaires and ICP-MS results, a total of 94 samples were deemed valid for further data analyses. Results showed levels of breastmilk lead (Pb) and iron (Fe) were outside the reference range from authoritative data. Correlation analyses found Pb levels to negatively associate with dietary fibre intake. Additionally, Fe levels were negatively associated with alcohol and dairy consumption. In terms of Zn levels, it was positively associated with tea and vitamin B1 intake. Zn was also negatively associated with seafood consumption. The study concluded dietary factors to associate with metal levels within breastmilk. Recommendations were made to increase consumption of dietary fibre, tea and foods rich in vitamin B1 for gestational and postpartum women. Conversely, alcohol consumption continues to be discouraged for this population. Furthermore, careful considerations need to be taken for levels of dairy and seafood intake to minimize metal metabolism disruptions. Infant metal exposure requires critical attention and this needs to be initiated through the diet and lifestyle of their nursing mothers.