TY - JOUR
T1 - Concentrations of trace elements in human milk
T2 - Comparisons among women in Argentina, Namibia, Poland, and the United States
AU - Klein, Laura D.
AU - Breakey, Alicia A.
AU - Scelza, Brooke
AU - Valeggia, Claudia
AU - Jasienska, Grazyna
AU - Hinde, Katherine
N1 - Funding Information:
This work was supported by funding from the Harvard University Department of Human Evolutionary Biology awarded to LDK, AAB, and KH; the Harvard GSAS Graduate Society [Summer Predissertation Fellowship] awarded to LDK; Jagiellonian University [K/ZDS/006 113] awarded to GJ; and the National Science Foundation (www. nsf.gov) [BCS-0952264] to CV. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The authors would like to thank Steven Worthington at the Harvard Institutive for Quantitative Social Sciences for assistance developing the statistical analysis and Peter Ellison for helpful comments on the manuscript.
Publisher Copyright:
© 2017 Klein et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
PY - 2017/8
Y1 - 2017/8
N2 - Human milk contains essential micronutrients for growth and development during early life. Environmental pollutants, such as potentially toxic metals, can also be transferred to the infant through human milk. These elements have been well-studied, but changing diets and environments and advances in laboratory technology require re-examining these elements in a variety of settings. The aim of this study was to characterize the concentrations of essential and toxic metals in human milk from four diverse populations. Human milk samples (n = 70) were collected in Argentina (n = 21), Namibia (n = 6), Poland (n = 23), and the United States (n = 20) using a standardized mid-feed collection procedure. Milk concentrations of calcium, zinc, iron, copper, manganese, lead, arsenic, and cadmium were determined using inductively coupled plasma mass spectrometry (ICP-MS). We used standard multiple linear regression models to evaluate differences among populations, while including infant age, infant sex, and maternal parity status (multiparous or primiparous) as covariates. Concentrations of all elements, except zinc, varied across populations after controlling for infant age, infant sex, and maternal parity. Calcium and magnesium showed more differences across populations than iron or copper. There were no significant differences among population in zinc concentrations. Mean concentrations of lead, but not arsenic, were low compared to recently published values from other populations. The concentrations of trace elements in human milk are variable among populations. Limitations due to small sample sizes and environmental contamination of some samples prevent us from drawing robust conclusions about the causes of these differences.
AB - Human milk contains essential micronutrients for growth and development during early life. Environmental pollutants, such as potentially toxic metals, can also be transferred to the infant through human milk. These elements have been well-studied, but changing diets and environments and advances in laboratory technology require re-examining these elements in a variety of settings. The aim of this study was to characterize the concentrations of essential and toxic metals in human milk from four diverse populations. Human milk samples (n = 70) were collected in Argentina (n = 21), Namibia (n = 6), Poland (n = 23), and the United States (n = 20) using a standardized mid-feed collection procedure. Milk concentrations of calcium, zinc, iron, copper, manganese, lead, arsenic, and cadmium were determined using inductively coupled plasma mass spectrometry (ICP-MS). We used standard multiple linear regression models to evaluate differences among populations, while including infant age, infant sex, and maternal parity status (multiparous or primiparous) as covariates. Concentrations of all elements, except zinc, varied across populations after controlling for infant age, infant sex, and maternal parity. Calcium and magnesium showed more differences across populations than iron or copper. There were no significant differences among population in zinc concentrations. Mean concentrations of lead, but not arsenic, were low compared to recently published values from other populations. The concentrations of trace elements in human milk are variable among populations. Limitations due to small sample sizes and environmental contamination of some samples prevent us from drawing robust conclusions about the causes of these differences.
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U2 - 10.1371/journal.pone.0183367
DO - 10.1371/journal.pone.0183367
M3 - Article
C2 - 28817665
AN - SCOPUS:85027726895
SN - 1932-6203
VL - 12
JO - PloS one
JF - PloS one
IS - 8
M1 - e0183367
ER -