Supplementation of a cereal-milk formula with haem iron palliates the adverse effects of iron deficiency on calcium and magnesium metabolism in rats

Fermented goat milk consumption during anaemia recovery: ergogenic effect and improvement of skeletal muscle homeostasis

PURPOSE

Anaemia is associated with fatigue and diminished muscular oxygenation, which may affect skeletal muscle (SM). No studies are available about the SM modifications during anaemia recovery; therefore, the aim of this study is to study SM homeostasis during anaemia recovery with fermented milks.

METHODS

Forty male Wistar rats were placed on a pre-experimental period of 40 days, divided in two groups (control group receiving normal-Fe diet and Fe-deficient group receiving low-Fe diet). Lately, rats were fed with fermented goat or cow milk-based diets, with normal-Fe content during 30 days. After feeding the fermented milks, leptin, adiponectin, non-esterified fatty acids (NEFA) and protein expression (UCP1, PepT1 and irisin) within the SM were assessed.

RESULTS

Adiponectin decreased in both groups of animals fed fermented goat milk, while leptin and NEFA increased. UCP1 protein expression increased in control and anaemic animals fed fermented goat milk. UCP1 also increased in both group of anaemic animals fed either fermented cow or goat milk in comparison with their controls. Irisin increased in both group of animals fed fermented goat milk. Finally, PepT1 also showed an increased expression in control and anaemic rats fed fermented goat milk and the anaemia also induced an over-expression of this transporter in animals fed either fermented cow or goat milk.

CONCLUSION

Fermented goat milk consumption during anaemia recovery diminishes adiposity depots and enhances lipolysis, increasing UCP1, PepT1 and irisin protein expression, featuring an ergogenic effect in the SM which is an important endocrine regulator of body metabolism.

Bioavailability of heme iron in biscuit filling using piglets as an animal model for humans

The objective of this work was to evaluate the bioavailability of heme iron added to biscuit filling. It comprised two stages: first, the development of the heme iron enriched biscuit filling; second, the evaluation of the bioavailability of the mineral in fattening piglets. Two groups were selected randomly and fed: a) Low iron feed and biscuits with heme iron supplemented filling; b) Normal feed (with ferrous sulphate). Weight and blood parameters were measured every fifteen days. Averages were compared after duplicate analyses. The filling had a creamy appearance, chocolate taste and smell, appropriate spreadability, heme iron content of 2.6 mg per gram and a shelf-life of a month. The heme iron supplemented pigs registered a greater (P<0.05) weight gain (27.8% more than the control group). Mortality in the heme iron group was 10%, compared to 50% in the control group. The amount of iron measured in the different compartment was greater in the heme group (3315 mg) than in the control group (2792 mg). However, the amount of iron consumed in the latter was greater. We show that an acceptable product with high heme iron content can be formulated, suitable for use as biscuit filling. The heme iron supplement produced better weight increase and lesser mortality in fattening pigs. The bioavailability of heme iron was 23% greater (P<0.05) compared to ferrous sulphate.

Iron availability: An updated review

Iron is an essential trace element in human nutrition and its deficiency is a world nutritional problem. Due to the high prevalence of anaemia in developing and industrialized countries, it is necessary to maintain a suitable iron intake through diet in order to achieve an appropriate status of this element in the body. For this reason, accurate knowledge of iron availability of foods is essential in order to plan intervention strategies that improve deficient situations of this nutrient. Regarding to the two forms of iron present in foods, heme iron has greater availability than non-heme iron. Beside this, non-heme iron availability is conditioned by several dietary factors, such as classic factors (meat, ascorbic acid, fibre, phytic acid, polyphenols) and new factors (caseinophosphopeptides and fructo-oligosaccharides with prebiotic characteristics). For that reason, the aim of this paper is to accurately review all investigations reported in the past decade related to dietetic factors that influence the bioavailability of different iron forms.

The effect of cysteine and 2,4-dinitrophenol on heme and nonheme absorption in a rat intestinal model

Previous studies have showed that purified heme iron forms insoluble polymers that are poorly absorbed. The presence of peptides and of amino acids maintaining heme iron in a soluble form could improve its bioavailability. The digestive uptake and transfer of a concentrated hydrolysate of heme peptides (HPH) and of iron gluconate (Gluc) at 100 µM were compared in vitro in a Ussing chamber. The effects of an enhancing amino acid (L-cysteine) on the uptake and transfer of both forms were assessed. An inhibitor of the oxidative phosphorylation (2,4-dinitrophenol; DNP) was used to differentiate the active and passive mechanisms of the absorption. The mucosal uptake (%Tot) and enterocyte transfer (%S) of the two sources of iron did not differ. DNP significantly reduced %Tot and %S of both forms. Cysteine significantly enhanced %Tot and %S of HPH and Gluc, partly corrected the inhibition exerted by DNP on %Tot of HPH and %S of both forms, and fully restored %Tot of Gluc. In presence of peptides produced by globin hydrolysis, the absorption of hemoglobin iron was efficient; it was mostly energy dependent and, therefore, should have occurred by a regulated transcellular pathway. Cysteine enhanced the passive uptake of iron and the passive processes involved in the enterocyte transfer of the common pool made of both sources (heme and nonheme) of iron. These results showed that heme iron can be purified and concentrated without impairing its digestive absorption, provided it remains in presence of peptides or amino acids.