Trace-element status in milk and plasma of Kuwaiti and non-Kuwaiti lactating mothers

There is a wide Variation in the reported data on the concentrations of tra ce elements in human milk from different countries, but such data are not a vailable for Kuwait. The objective of this study was to analyze the concent ration of zinc, copper, manganese, and iron in milk and plasma of Kuwaiti a nd non-Kuwaiti mothers during prolonged lactation. Milk samples (from 34 do nors) were collected early in the morning before feeding the infant. Trace elements were analyzed using atomic absorption spectrophotometry. Protein c ontent and activity of superoxide dismutase were assayed spectrophotometric ally. Concentration of zinc, copper, iron, and total protein and activity o f superoxide dismutase in milk and of only zinc in plasma of Kuwaiti mother s were significantly higher than those of non-Kuwaitis. Concentration of zi nc, copper, manganese, and total protein in milk of both groups decreased a s lactation continued but that of milk iron and plasma trace elements remai ned unchanged. The data of Kuwaiti mothers are consistent with those of pre vious reports on hyperurecemia, and the prevalence of obesity was found to be higher in the Kuwaiti population than in other countries. High protein c ontent in association with high concentration of trace elements in milk of Kuwaiti versus non-Kuwaiti mothers may indicate that protein content in mil k is an important determining factor for the concentration and bioavailabil ity:of these elements. (C)Elsevier Science Inc. 2000.