Silvia Hijano

A New Insight to Bone Turnover: Role of -3 Polyunsaturated Fatty Acids

Background. Evidence has shown that long-chain polyunsaturated fatty acids (LCPUFA), especially the ω-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are beneficial for bone health and turnover. Objectives. This review summarizes findings from both in vivo and in vitro studies and the effects of LC PUFA on bone metabolism, as well as the relationship with the oxidative stress, the inflammatory process, and obesity. Results. Some studies in humans indicate that LCPUFA can increase bone formation, affect peak bone mass in adolescents, and reduce bone loss. However, the cellular mechanisms of action of the LCPUFA are complex and involve modulation of fatty acid metabolites such as prostaglandins, resolvins and protectins, several signaling pathways, cytokines, and growth factors, although in certain aspects there is still some controversy. LCPUFA affect receptor activator of nuclear factor κ β (RANK), a receptor found on the osteoclast, causing bone resorption, which controls osteoclast formation. Conclusions. Since fatty acids are an endogenous source of reactive oxygen species, free radicals alter the process of bone turnover; however, although there are clinical evidences linking bone metabolism and dietary lipids, more clinical trials are necessary to prove whether ω-3 PUFA supplementation plays a major role in bone health.

Production and chemical composition of two dehydrated fermented dairy products based on cow or goat milk.

The aim of this study was to identify the differences between the main macro and micronutrients including proteins, fat, minerals and vitamins in cow and goat dehydrated fermented milks. Fermented goat milk had higher protein and lower ash content. All amino acids (except for Ala), were higher in fermented goat milk than in fermented cow milk. Except for the values of C11:0, C13:0, C16:0, C18:0, C20:5, C22:5 and the total quantity of saturated and monounsaturated fatty acids, all the other fatty acid studied were significantly different in both fermented milks. Ca, Mg, Zn, Fe, Cu and Se were higher in fermented goat milk. Fermented goat milk had lower amounts of folic acid, vitamin E and C, and higher values of vitamin A, D3, B6 and B12. The current study demonstrates the better nutritional characteristics of fermented goat milk, suggesting a potential role of this dairy product as a high nutritional value food.

Goat milk consumption modulates liver divalent metal transporter 1 (DMT1) expression and serum hepcidin during Fe repletion in Fe-deficiency anemia

Iron deficiency is the most prevalent micronutrient deficiency worldwide. In spite of the crucial role of hepatocyte divalent metal transporter 1 (DMT1) and hepcidin in Fe metabolism, to date, no studies have directly tested the role of these proteins in liver Fe metabolism during Fe repletion after induced Fe-deficiency anemia. Therefore, the aim of the current study was to assess the effect of goat or cow milk-based diets on Fe metabolism in one of the main body storage organs, the liver, during the course of Fe repletion with goat or cow milk-based diets in anemic rats. Animals were placed on a preexperimental period of 40 d, a control group receiving a normal-Fe diet and the Fe-deficient group receiving a low-Fe diet (5 mg of Fe/kg of diet). Rats were fed for 30 d with goat or cow milk-based diets with normal Fe content (45 mg of Fe/kg of diet). The hematological parameters, serum hepcidin, hepatosomatic index, liver Fe content, and liver DMT1 expression were determined. During the recovery of the anemia with milk-based diets, the restoration of liver Fe content and hematological parameters, especially with goat milk, increased the red blood cell count, favoring the oxygen supply and weight gain. Moreover, goat milk consumption potentiates liver DMT1 expression, enhancing Fe metabolism and storage. In addition, the increase in serum hepcidin in anemic rats observed in the current study also explains and supports the higher liver Fe content after supplying goat milk, because it blocks the liberation of Fe from hepatocytes, increasing its storage in liver.

Interactions Between Omega-3 Fatty Acids and Iron

Fe is an essential micronutrient, required for many biological processes. Apart from its role in hemoglobin, it is central to many redox processes throughout the body. The long-chain polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA; 22:6 n−3) is ubiquitously present in the plasma membrane of biological cells and has a key role as an essential macronutrient in all mammals since it participates in a number of biological functions in the maintenance of homeostasis. This chapter summarizes the interactive role of Fe and DHA in physiological situations and nutritional deficiencies and reveals that DHA stimulates Fe metabolism, and several studies have suggested that Fe deficiency is associated with an alteration in tissue fatty acid content and hypomyelination indicating a clear interaction between Fe and DHA metabolism.