Essential and toxic elements in human milk concentrate with human milk lyophilizate: A preclinical study

Abstract

Concentrated human milk (HM-concentrate) can be obtained from the simple and inexpensive method of donated breast milk direct lyophilization. A previous study reported that HM-concentrate contains the adequate amount of main macro- and micronutrients for use as a nutritional resource for preterm infants with very low birth weight admitted to neonatal intensive care units. However, further details need to be elucidated about HM-concentrate composition, particularly its content of essential and potentially toxic trace elements. Therefore, this study aimed to determine the concentration of essential and toxic elements in human milk considered baseline (HM-baseline) and HM-concentrate, as well as to quantify changes in concentration of these elements after the HM concentration process. The concentration of Aluminum, Arsenic, Cadmium, Chromium, Iron, Mercury, Manganese, Nickel, Lead, Selenium, Tin, and Thallium was analyzed by inductively coupled plasma-mass spectrometry (ICP-MS). Moreover, Bayesian linear mixed effect models were applied to estimate the mean difference between HM-baseline and HM-concentrate samples. After comparison (HM-concentrate versus HM-baseline), a significant increase in concentration was observed only for Manganese (0.80 μg/L; 95% CrI [0.16; 1.43]) and Selenium (6.74 μg/L; 95% CrI [4.66; 8.86]), while Lead concentration (−6.13 μg/L; 95% CrI [-8.63; −3.61]) decreased. This study provides latest and reliable information about HM composition. After milk concentration by lyophilization, there was a significant increase only in the essential elements Manganese and Selenium. The essential micronutrient content in HM-concentrate was similar or higher than that in preterm mothers' milk, which suggests it is viable for nutritional support of preterm infants. In addition, the low concentrations of potentially toxic elements in HM-concentrate indicates that it is safe for consumption by premature newborns.

Heavy Metals and Trace Elements in Human Breast Milk from Industrial/Mining and Agricultural Zones of Southeastern Spain

“…Arsenic was detected in six samples. The mean values found are higher than most of those found in the reviewed literature [32,41,46,47]. All samples with arsenic exceeded the maximum tolerance limit.…”

“…Thirty-nine mothers had detectable levels of nickel in their milk. Compared with the levels found in other studies, these results are higher than those of most authors [24,32,51,52]. The mother with the highest level of nickel in milk was a 36-year-old multiparous woman residing in the industrial/mining zone, who works outside the home, taking vitamin supplements during pregnancy and breastfeeding, with a baby of 3 months and a total of 3 months of breastfeeding, including the time for previous children.…”

“…Cadmium was detected in 3 of the 50 samples with a mean concentration similar to those found in breast milk samples from women in Poland [30], lower than those in Lebanon [31] and higher than those in Sweden [24], Greece [22], Italy [27] and Brazil [32]. The three samples exceeded the maximum recommended limits.…”

“…Iron was detected in 33 samples with a mean concentration higher than in most publications [22,24,32,[48][49][50]. Nine samples exceeded the maximum allowed level (350-720 µg/L).…”

“…Mercury was detected at a mean concentration higher than that referenced in different studies carried out in Austria [33,34], China [35], Germany [36,37], Sweden [38], Slovakia [23,39], Turkey [40], Cyprus [41] and Brazil [32]. Twenty-seven samples exceeded the maximum tolerable limit.…”