The effect of food and nutrients on iron overload: what do we know so far?

Iron incorporation in red blood cells of pediatric sickle cell anemia: a stable isotope pilot investigation

BACKGROUND/OBJECTIVES

Sickle cell anemia (SCA) is marked by hypoxia, inflammation, and secondary iron overload (IO), which potentially modulate hepcidin, the pivotal hormone governing iron homeostasis. The aim was to evaluate the iron incorporation in red blood cells (RBC) in SCA pediatric patients, considering the presence or absence of IO.

SUBJECTS/METHODS

SCA children (n = 12; SCAtotal) ingested an oral stable iron isotope (57Fe) and iron incorporation in RBC was measured after 14 days. Patients with ≥1000 ng/mL serum ferritin were considered to present IO (SCAio+; n = 4) while the others were classified as being without IO (SCAio-; n = 8). Liver iron concentration (LIC) was determined by Magnetic Resonance Imaging (MRI) T2* method.

RESULTS

The SCAio+ group had lower iron incorporation (mean ± SD: 0.166 ± 0.04 mg; 3.33 ± 0.757%) than SCAio- patients (0.746 ± 0.303 mg; 14.9 ± 6.05%) (p = 0.024). Hepcidin was not different between groups. Iron incorporation was inversely associated with serum ferritin level (SCAtotal group: r = -0.775, p = 0.041; SCAio- group: r = -0.982; p = 0.018) and sickle hemoglobin (HbS) presented positive correlation with iron incorporation (r = 0.991; p = 0.009) in SCAio- group. LIC was positively associated with ferritin (SCAtotal: r = 0.921; p = 0.026) and C reactive protein (SCAio+: r = 0.999; p = 0.020).

CONCLUSION

SCAio+ group had lower iron incorporation in RBC than SCAio- group, suggesting that they may not need to reduce their intake of iron-rich food, as usually recommended. Conversely, a high percentage of HbS may indirectly exacerbate hypoxia and seems to increase iron incorporation in RBC.

TRIAL REGISTRATION

This trial was registered at www.ensaiosclinicos.gov.br . Identifier RBR-4b7v8pt.

Iron homeostasis in older adults: balancing nutritional requirements and health risks

Iron plays a crucial role in many physiological processes, including oxygen transport, bioenergetics, and immune function. Iron is assimilated from food and also recycled from senescent red blood cells. Iron exists in two dietary forms: heme (animal based) and non-heme (mostly plant based). The body uses iron for metabolic purposes, and stores the excess mainly in splenic and hepatic macrophages. Physiologically, iron excretion in humans is inefficient and not highly regulated, so regulation of intestinal absorption maintains iron homeostasis. Iron losses occur at a steady rate via turnover of the intestinal epithelium, blood loss, and exfoliation of dead skin cells, but overall iron homeostasis is tightly controlled at cellular and systemic levels. Aging can have a profound impact on iron homeostasis and induce a dyshomeostasis where iron deficiency or overload (sometimes both simultaneously) can occur, potentially leading to several disorders and pathologies. To maintain physiologically balanced iron levels, reduce risk of disease, and promote healthy aging, it is advisable for older adults to follow recommended daily intake guidelines and periodically assess iron levels. Clinicians can evaluate body iron status using different techniques but selecting an assessment method primarily depends on the condition being examined. This review provides a comprehensive overview of the forms, sources, and metabolism of dietary iron, associated disorders of iron dyshomeostasis, assessment of iron levels in older adults, and nutritional guidelines and strategies to maintain iron balance in older adults.

Evaluation of dietary composition between hemoglobin categories, total body iron content and adherence to multi-micronutrients in preschooler residents of the highlands of Puno, Peru

BACKGROUND

The anemia prevalence is higher in highlands populations. It is assumed that iron deficiency anemia (IDA) in children is mainly due to low dietary intake. However, other suggest that high prevalence of anemia is due to an inappropriate hemoglobin (Hb) adjustment for altitude.

MATERIALS AND METHODS

Cross-sectional study conducted in 338 preschoolers (PSC) from Puno-Peru. Hb was measured in whole blood, and ferritin, Soluble transferrin receptor, and Interleukin 6 in serum.The dietary iron intake was assessed by 24-h dietary recall, using NutriCap Software. Hb concentration was assessed as adjusted or unadjusted for altitude.

RESULTS

With unadjusted Hb, the anemia prevalence was 4.7%, whereas after Hb correction, the prevalence raised-up to 65.6% (p < 0.001). Reciprocally, erythrocytosis proportion decreased from 20.35 to 0.30% (p < 0.001). Total Body Iron (TBI) showed that 7.44% had ID and 0.32% had IDA. PSC with normal unadjusted Hb levels have more protein and micronutrients intake than anemic ones. PSC with erythrocytosis consumed less fat, and more niacin and ascorbic acid than anemics. Total iron intake was lower in anemic than the other groups, but without statistical significance due to the standard deviation of the data in a small number of anemic PSC (n = 16). TBI, unadjusted Hb, and adjusted Hb were not different between groups consuming or not multimicronutrients.

CONCLUSIONS

The consumption of iron and iron status in children who live at high altitude is adequate, and that anemia could be due to other micronutrient deficiencies and/or that the adjustment of Hb by altitude is inappropriate.

Perspectives on Iron Deficiency as a Cause of Human Disease in Global Public Health

Iron (Fe) is a necessary trace element in numerous pathways of human metabolism. Therefore, Fe deficiency is capable of causing multiple health problems. Apart from the well-known microcytic anemia, lack of Fe can cause severe psychomotor disorders in children, pregnant women, and adults in general. Iron deficiency is a global health issue, mainly caused by dietary deficiency but aggravated by inflammatory conditions. The challenges related to this deficiency need to be addressed on national and international levels. This review aims to summarize briefly the disease burden caused by Fe deficiency in the context of global public health and aspires to offer some hands-on guidelines.

Proposed dietary recommendations for iron overload: a guide for physician practice

PURPOSE OF REVIEW

Iron overload disorders such as hemochromatosis involve unregulated absorption of dietary iron, leading to excessive iron accumulation in multiple organs. Phlebotomy is the standard of care for removal of excess iron, but dietary modification is not standardized in practice. The purpose of this article is to help standardize hemochromatosis diet counseling based on commonly asked patient questions.

RECENT FINDINGS

The clinical benefit regarding dietary modification in iron overload patients is limited due to lack of large clinical trials, but preliminary results are promising. Recent studies suggest diet modification could reduce iron burden in hemochromatosis patients resulting in less annual phlebotomy as supported through small patient studies, concepts of physiology, and animal studies.

SUMMARY

This article is a guide for physicians to counsel hemochromatosis patients based on commonly asked questions such as foods to avoid, foods to consume, use of alcohol, and use of supplements. The goal of this guide is to help standardize hemochromatosis diet counseling to reduce phlebotomy amount in patients. Standardization of diet counseling could help facilitate future patient studies to analyze the clinical significance.

Food Consumption of People with Sickle Cell Anemia in a Middle-Income Country

Sickle cell anemia (SCA) is a genetic and hemolytic disease globally characterized by social vulnerability. Food consumption has been insufficiently analyzed in SCA. Secondary iron overload is often observed. This leads to unreliable recommendations for dietary iron restriction. We assessed food consumption and iron intake among adults with SCA. Considering the guidelines for healthy eating, foods were grouped according to the NOVA classification. This transversal study included 74.4% of eligible patients who were registered in the reference center for SCA treatment in Rio de Janeiro, Brazil, in 2019. Data on food consumption were collected through 24 h recall. The monthly household income of 82.3% of patients was less than $770. The consumption of fresh or minimally processed foods was directly associated with monthly household income (p < 0.0001; η₂ = 0.87). Ultra-processed foods provided more than one-third of the total energy intake (35.2%). The prevalence of inadequate iron intake was about 40% among women, while that of iron intake above the tolerable upper limit was 0.8%. People from lower socioeconomic classes had the lowest iron intake. Strategies to encourage the consumption of fresh or minimally processed foods are needed considering the requirement of an antioxidant diet in SCA. These findings highlight the need for health equity to ensure food security and healthy eating in SCA.

Effects of Moderate Consumption of Red Wine on Hepcidin Levels in Patients with Type 2 Diabetes Mellitus

Iron overload is often associated with type 2 diabetes (T2D), indicating that hepcidin, the master regulator of iron homeostasis, might be involved in diabetes pathogenesis. Alcohol consumption may also result in increased body iron stores. However, the moderate consumption of wine with meals might be beneficial in T2D. This effect has been mainly attributed to both the ethanol and the polyphenolic compounds in wine. Therefore, we examined the effects of red wine on hepcidin in T2D patients and non-diabetic controls. The diabetic patients (n = 18) and age- and BMI-matched apparently healthy controls (n = 13) were men, aged 40−65 years, non-smoking, with BMI < 35 kg/m2. Following a 2-week alcohol-free period, both groups consumed 300 mL of red wine for 3 weeks. The blood samples for the iron status analysis were taken at the end of each period. The red wine intake resulted in a decrease in serum hepcidin in both the diabetic subjects (p = 0.045) and controls (p = 0.001). The levels of serum ferritin also decreased after wine in both groups, reaching statistical significance only in the control subjects (p = 0.017). No significant alterations in serum iron, transferrin saturation, or soluble transferrin receptors were found. The suppression of hepcidin, a crucial iron-regulatory hormone and acute-phase protein, in T2D patients and healthy controls, is a novel biological effect of red wine. This may deepen our understanding of the mechanisms of the cardiometabolic effects of wine in T2D.

The reciprocal interaction between polyphenols and other dietary compounds: Impact on bioavailability, antioxidant capacity and other physico-chemical and nutritional parameters

Polyphenols are plant secondary metabolites, whose biological activity has been widely demonstrated. However, the research in this field is a bit reductive, as very frequently the effect of individual compound is investigated in different experimental models, neglecting more complex, but common, relationships that are established in the diet. This review summarizes the data that highlighted the interaction between polyphenols and other food components, especially macro- (lipids, proteins, carbohydrates and fibers) and micronutrients (minerals, vitamins and organic pigments), paying particular attention on their bioavailability, antioxidant capacity and chemical, physical, organoleptic and nutritional characteristics. The topic of food interaction has yet to be extensively studied because a greater knowledge of the food chemistry behind these interactions and the variables that modify their effects, could offer innovations and improvements in various fields ranging from organoleptic, nutritional to health and economic field.

Influence of Fe(III) on the Fluorescence of Lysozyme: a Facile and Direct Method for Sensitive and Selective Sensing of Fe(III)

Lysozyme is widely used for the synthesis of nanomaterials (e.g., gold nanoparticle) to fluorescently sense metal ions. However, the effect of metal ions on the fluorescence of lysozyme is not studied yet. Herein, we have explored the interactions of lysozyme with different metal ions to develop a direct sensing platform for Fe(III). It has been observed that the fluorescence of lysozyme was slightly decreased in the presence of Cu(II), Hg(II), As(V), Co(II), Cd(II), Cr(II), Fe(II), Mn(II), Pb(II), and Zn(II), while a significant decrease in the lysozyme fluorescence was observed for Fe(III). The effect of thermal stability on the fluorescence quenching was also studied from 25 to 60 °C. In the present study, the lysozyme sensing probe was able to selectively and accurately detect 0.5-50 ppm of Fe(III) with a LOD of 0.1 ppm (1.8 µM) at 25 °C.