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Optimal Nutrition for Women
Published in Michelle Tollefson, Nancy Eriksen, Neha Pathak, Improving Women's Health Across the Lifespan, 2021
Kayli Anderson, Kaitlyn Pauly, Debra Shapiro, Vera Dubovoy
There are two types of dietary iron: heme and nonheme iron. Heme iron is found solely in animal foods, while nonheme iron is found primarily in plant-based foods. Heme iron is more readily absorbed than nonheme iron, which is not necessarily a positive characteristic since it is possible to absorb heme iron in excess. Excess heme iron has been associated with an increased risk of coronary heart disease, breast cancer, esophageal cancer, and stomach cancer.123–125 Therefore, plant-based iron sources may be safer since the body is able to regulate its nonheme iron better. Many factors affect the absorption of nonheme iron, such as other foods it is eaten with and a person’s current iron status. Plant foods rich in iron include leafy green vegetables, beans, and whole grains. Iron-rich foods should ideally be eaten with vitamin C-rich foods to enhance absorption. Certain foods interfere with iron absorption, like coffee and tea, which contain tannins, and calcium supplements.120
Components of Nutrition
Published in Christopher Cumo, Ancestral Diets and Nutrition, 2020
Proteins perform crucial functions. For example, insulin, mentioned earlier and having fifty-one amino acids, is the hormone that tells cells to admit glucose.69 In this way, insulin regulates the amounts of glucose inside and outside cells. Insulin also regulates glucose by telling the liver to store excess for release when the sugar becomes scarce in blood. Heme proteins, defined by the presence of iron (Fe), shuttle molecules and electrons throughout the body. Hemoglobin, a component of red blood cells, brings oxygen to cells and removes carbon dioxide for transport to the lungs. Carbon dioxide is a greenhouse gas, though human respiration emits little compared to factories and automobiles. The protein keratin helps form hair and skin. Proteins known as enzymes catalyze the body’s reactions. For example, enzymes pepsin and trypsin aid protein digestion by catalyzing cleavage of amino acid peptide bonds, mentioned earlier. Integral to the immune system, proteins that combat pathogens are known as antibodies. Attention has focused on the protein interferon, which targets viruses.
Medicine
Published in Seema Khan, Get Through, 2020
Synthesis of heme, an important constituent of haemoglobin, occurs in the liver. The process is complex in which a large number of enzymes are needed at each step to convert haem precursors (known as porphyrins) into haem itself. Enzyme deficiency can occur at any step of the process leading to accumulation of porphyrins and to symptoms of porphyria. Porphyria is in fact a group of disorders which includes acute intermittent porphyria, cutaneous porphyria and mixed porphyria. Drugs, particularly those containing hormones (e.g. the pill or HRT), infections, smoking and alcohol are known precipitants.
SARS-CoV-2 Infection Dysregulates Host Iron (Fe)-Redox Homeostasis (Fe-R-H): Role of Fe-Redox Regulators, Ferroptosis Inhibitors, Anticoagulants, and Iron-Chelators in COVID-19 Control
Published in Journal of Dietary Supplements, 2023
Sreus A.G. Naidu, Roger A. Clemens, A. Satyanarayan Naidu
HO-1 mediates catalytic breakdown of heme, a potent pro-oxidant and pro-inflammatory molecule (206). Heme is an iron chelate with an essential role in O2 transport/detoxification, cellular respiration, and signal transduction. Due to its potential toxicity, heme is formed and degraded within an individual nucleated cell (207) and the HO enzymes serve this function for cellular defense (208). The redox-active iron released from HO-1 activity stimulates ferritin synthesis for ultimate iron detoxification and cytoprotection with its ferroxidase activity (209). Elevated ferritin levels provide an adaptive response to maintain a low redox-active iron pool; thereby reduce Fenton chemistry and oxidative stress (214). The HO-1-regulated Fe-R-H provides cytoprotective function via endogenous mechanisms involving genes like TIGAR (‘TP53-induced glycolysis and apoptosis regulator’) to sustain body’s antioxidant response against oxidative stress (210). The role of HO-1 to protect against SARS-CoV-2 is probably an emergency inducible defense mechanism to ameliorate oxidative stress from heme-released oxidants.
Prothrombotic state and calcium deficiency in early pregnancy are risk factors for gestational diabetes mellitus: a retrospective cohort study
Published in Gynecological Endocrinology, 2022
Qingyun Liu, Shanshan Wei, Feng Wang
A meta-analysis including six case-control studies indicated that IDA was associated with reduced GDM risk [30], which was not validated in our cohort. The inconsistency should not be due to the sample size of this study, since the statistical power based on current results was 0.998. Recently, two systematic reviews revealed that intake of heme iron, but not total iron or non-heme iron, was significantly associated with GDM risk [31,32]. As an important source of dietary iron, heme iron is derived largely from hemoglobin and myoglobin in meat, poultry, and fish. Hence, IDA probably served as a surrogate for other factors such as dietary habit, nutritional inadequacy and reduced BMI, leading to secondary association with GDM if covariates were not carefully handled. In addition, the difference in ethnicity may contribute to inconsistent results. Potential follow-up bias and confounding bias could lead to the insignificant association of IDA with GDM. For example, 3066 pregnant women did not perform OGTTs in our hospital and their GDM outcomes were not available, which could introduce follow-up bias.
The mechanisms and therapeutic targets of ferroptosis in cancer
Published in Expert Opinion on Therapeutic Targets, 2021
Long Ye, Fengyan Jin, Shaji K. Kumar, Yun Dai
Intracellular Fe2+ is usually stored in the form of ferritin, which contains two subunits, FTH1 and FTL. The former executes the role of iron storage. Down-regulation of FTH1 increases Fe2+ concentration and promotes ferroptosis[11]. Ferritin is degraded via nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy, therefore releasing Fe2+ to trigger ferroptosis. While mitochondrial ferritin (FtMt) sequesters Fe2+ and thus confers resistance to ferroptosis, the accumulation of free Fe2+ in mitochondria exacerbates erastin-induced ferroptosis. Heme serves as another source of Fe2+ in the cell, which can be decomposed by heme oxygenase-1 (HO-1) and thereby release Fe2+. Therefore, HO-1 is also involved in the regulation of ferroptosis.