Consumption of highly processed foods: Effects on bioavailability and status of zinc and copper in adolescents

Do cooking techniques influence copper bioaccesibility in foods after in vitro digestion/fermentation in adults and children?

Cu is essential for the growth and organism health. Classically, its available fraction has been studied by in vitro digestion studies as a measure of bioaccessibility of Cu (Cu-BA). In this work we applied a novel in vitro digestion/fermentation method to multiple foods subjected to different home cooking techniques (raw form vs. frying, roasting, toasting, boiling and grilling) by metabolization with faecal inoculate from healthy adults (HE-AD), and healthy children (HE-CH) and sick children (children with gluten related disorders, GRD-CH; children with obesity, OB-CH; and children with allergy/intolerance to cow's milk proteins, AICM-CH). In raw and cooked foods the bioaccessibility of Cu in the small intestine (Cu-BASI) was higher vs. that in the Cu bioaccessibility in the large intestine (Cu-BALI) (30.8 ± 15.4 and 28.2 ± 14.7 vs. 18.4 ± 21.2 and 22.8 ± 22.1 %, respectively; p < 0.001). Total Cu-BA in cooked foods (51.0 ± 24.4 %) was higher than that in raw foods (49.0 ± 25.1 %). In cereals, total Cu-BA was higher in the raw form, as well as in whole grains and those with gluten (p < 0.05). In vegetables, the most drastic cooking techniques (roasting and frying) show higher values of total Cu-BA compared to raw form and boiling. The Cu-BALI in HE-CH (37.7 ± 23.7 %) is higher than that determined in HE-AD (14.1 ± 18.5 %) and sick children (GRD-CH: 14.6 ± 19.8; OB-CH: 15.5 ± 17.8; and AICM-CH: 26.9 ± 19.3 %; p < 0.001). In conclusion, cooking techniques influence Cu-BA depending on the food group. Total Cu-BA, as well as that determined in the large and small intestine varied according to the category, group and specific foods, which is related to their different composition and species of the element. In healthy children, total Cu-BALI is higher than in adults and celiac, obese and allergic children probably due to growth requirements and specific microbiota.

Non-ceruloplasmin-bound copper and copper speciation in serum with extraction using functionalized dendritic silica spheres followed by ICP-MS detection

The quantification of non-ceruloplasmin-bound copper (NCBC) and total copper in biological fluids is highly required for understanding the correlation of copper with various physiological processes and diseases. In the present work, we developed dendritic spherical silica particles functionalized with EDTA, shortly as DMSPs-EDTA, from the hydrolysis of tetraethyl orthosilicate with the aid of structure-directing agents and subsequent modification of EDTA. DMSPs-EDTA serves as adsorbent with abundant binding sites to facilitate efficient extraction of NCBC. The retained NCBC on DMSPs-EDTA may be readily recovered by stripping with HNO₃ (2 mol L^-1). By hyphenating with ICP-MS detection, it provides a limit of detection of 1.3 pmol for NCBC. The degradation of ceruloplasmin with 200 mmol L^-1 H₂O₂ releases the bound copper as NCBC to distribute among other ligands, which may be efficiently retained by the adsorbent and facilitate the detection of total copper. The linear ranges of 0.21-10 μmol L^-1 and 0.42-30 μmol L^-1 were derived for the detection of NCBC and total copper. The recovery rates for spiked NCBC or total copper in serum were derived to be 97-108% and 94-102%, respectively. The analysis of serum for a healthy subject resulted in 1.8 μmol L^-1 NCBC and 9.5 μmol L^-1 total copper. In addition, the proportions of 8.5-12% for NCBC were derived from the serum of healthy adults, while those for the patients with lung, hepatocellular and esophageal carcinoma were found to be 10-12%, illustrating no obvious difference against the normal group.

Assessing the dietary intake of calcium, magnesium, iron, zinc and copper in institutionalised children and adolescents from Guatemala. Contribution of nutritional supplements

In childhood and adolescence an adequate mineral intake is essential for normal growth and immune function, and to prevent chronic diseases in adulthood. The aim of this study was to analyse the dietary intake of Ca, Mg, Fe, Zn and Cu in children and adolescents from an orphanage-school in Guatemala and to assess the mineral contribution of nutritional supplements used by this population. Mineral content was analysed in nutritional supplements, bioaccesible fractions obtained after an in vitro gastrointestinal method, and diets sampled by a 7-day duplicate diet study. The average mineral content in the duplicate diets, including supplements, was (mg/d): Ca 452, Mg 230, Fe 25, Zn 8 and Cu 0.22. Especially Ca and Cu values were below recommended daily intakes. The content of these minerals in the nutritional supplements (mg/serving) was 49-112 for Ca, 1.2-3.8 for Fe, 24-47 for Mg, 0.7-4.16 for Zn and 0.08-0.23 for Cu. A great proportion of dietary minerals was provided by supplements, the contribution of which was: Ca 53.1%, Mg 58.4%, Fe 27.6%. Zn 82.2% and Cu 98.5%. Mineral bioaccessibility in supplements was particularly low for Ca and, to a lesser extent, for Fe and Zn. In spite of the high supplement consumption (up to 4 servings/d) important mineral deficiencies were detected in the diet of institutionalised children. Findings suggest that formulation and nutritional values of supplements used in Latin America should be carefully reviewed, in order to be a useful tool in the prevention and treatment of hidden hunger.

Dose-Dependent Influence of Dietary Cu-Glycine Complex on Bone and Hyaline Cartilage Development in Adolescent Rats

Administration of the amino acid copper (Cu) complex ensures higher Cu bioavailability through enhanced absorption from intestine and decreases the dietary Cu level, compared to the recommended Cu dose. The objective of this study was to investigate the effect of Cu-low diet on the bone development in adolescent rats. Male rats at the age of 6 weeks were used in the 12-week experiment. The control diet provided the required Cu level from sulfate (S-Cu) and other diets were supplemented with Cu as a glycine complex (Cu-Gly) at 25%, 50%, 75%, and 100% of daily requirement. After the 12-week treatment, rats from the Cu-Gly100 group were heavier, compared to the other groups. The copper and calcium plasma and bone concentrations of the rats in the groups treated with the organic form of Cu (irrespective of its dose) was similar to the control values noted in the rats administered with S-Cu. A decrease in the femur weight and length was observed in the Cu-Gly75 and Cu-Gly50 groups. Cu-Gly increased the cross section area, mean relative wall thickness, and cortical index only in the Cu-Gly75 group. A decrease in the ultimate strength, elastic stress, and ultimate stress was noted in the Cu-Gly100 and Cu-Gly75 groups. In the Cu-Gly50 group, a decrease in the ultimate stress and an increase in the maximal elastic strength and bending moment were noted. Adolescent rats treated with Cu-Gly at a Cu-deficient level exhibited a dose-dependent strongly osteoporotic cancellous bone. Lower proteoglycan content was found in groups fed the Cu-low diet. In the control rats supplemented with S-Cu, there was no evident gradient in safranin O staining. It is difficult to indicate which dose of the Cu-Gly complex among the investigated Cu-poor diet exerted a positive effect on bone metabolism. It appears that the use of this Cu-Gly complex at a significantly reduced dose than S-Cu at the recommended dose did not inhibit the development of bone and hyaline cartilage in adolescent rats.

Assessing the effects of model Maillard compound intake on iron, copper and zinc retention and tissue delivery in adult rats

The behaviour of dietary Maillard reaction compounds (MRP) as metal chelating polymers can alter mineral absorption and/or retention. Our aim in this study was to analyse the long-term effects of the consumption of model MRP from glucose-lysine heated for 90 min at 150 °C (GL) on iron, copper and zinc whole-body retention and tissue delivery. For 88 days, weaning rats were fed a Control diet or one containing 3% GL, until reaching the adult stage. During the experimental period a mineral balance was conducted to investigate the mineral retention. At day 88, the animals were sacrificed, blood was drawn for haemoglobin determination and some organs were removed. Copper and zinc balances were unaffected (Cu: 450 vs. 375 μg; Zn: 6.7 vs. 6.2 mg for Control and GL groups, respectively) and no change was observed in whole-body delivery. Iron retention, too, was unaltered (11.2 mg for Control and GL groups) but due to the tendency toward decreased body weight in the GL group (248 vs. 233 g for the Control and GL groups), whole-body iron concentration was 13% higher in the GL group than in the Control group. Absorbed iron accumulated particularly in the liver (144 vs. 190 μg g(-1) for the Control and GL groups), thus reducing haemoglobin levels. The long-term intake of MRP induced iron accumulation in the body but this did not result in enhanced iron functionality, since the haemoglobin concentration declined. Taking into account the findings of our research group's studies of young and adult rats, we now corroborate the hypothesis that the negative effect of GL MRP consumption on iron functionality takes place regardless of the animals' stage of life.