Abstracts
Adolescents
Adolescents
Evaluated iron status and its determinants in healthy adolescents.
Mean total iron intakes of the boys were high [1.6 times recommended daily allowance (RDA)] and mean intakes of the girls were adequate (0.9 times RDA). Low heme iron intakes increased the risk of low iron stores (< 12 micrograms/L) in girls but not in boys.
The differences in iron status between boys and girls in adolescence results primarily from biological differences other than menstrual bleeding or insufficient iron intake. Furthermore, the results question the role of SF as an indicator of iron deficiency in adolescence, in particular if age and sex are not taken into consideration. We suggest that different reference values for SF, including the cut-off limit for low SF, adjusted for age and sex, should be considered. The high iron intakes and corresponding high SF values found in the older boys are noticeable in light of the possible negative health consequences of iron overload.
Sex differences in iron stores of adolescents: what is normal? Bergstrom-E; Hernell-O; Lonnerdal-B; Persson-LA J-Pediatr-Gastroenterol-Nutr. 1995 Feb; 20(2): 215-24.
Alcohol & Iron
Alcohol
In an attempt to elucidate further the mechanisms involved in alcohol-mediated liver damage and the correlation between alcohol and viruses in chronic liver lesions, we determined the levels of liver glutathione (GSH), thiobarbituric acid reactive substances (TBARS), iron (Fe), and zinc (Zn) in patients (#31) with chronic viral hepatitis (CAH), 6 with alcohol-related chronic hepatitis (CALD), 6 with alcoholic cirrhosis (AC), 8 with primary biliary cirrhosis (PBC), and 10 healthy controls (C).
Tissue levels of Fe were significantly increased in CALD and AC patients with respect to controls and CAH patients, whereas no significant difference was observed in Zn. These data confirm that patients with chronic ethanol exposure reveal a depletion in liver GSH content clearly correlated with an increase in lipid peroxidation and Fe liver storage.
Zinc, iron, and peroxidation in liver tissue. Cumulative effects of alcohol consumption and virus-mediated damage--a preliminary report. Farinati-F; Cardin-R; de-Maria-N; Lecis-PE; Della-Libera-G; Burra-P; Marafin-C; Sturniolo-GC; Naccarato-R. Biol-Trace-Elem-Res. 1995 Jan-Mar; 47(1-3): 193-9.
Antioxidants - LDL oxidation
Antioxidants - LDL oxidation
It is generally accepted that transition metals are required for cellular LDL oxidation. LDL may also be oxidized by iron and reducing agents in cell-free systems.
Lysosomal iron may be exocytosed from human monocyte-derived macrophages (HMDMs HMDMs and promote oxidation and uptake of LDL and thus induce foam cell formation.
Effects of iron- and hemoglobin-loaded human monocyte-derived macrophages on oxidation and uptake of LDL. Yuan-XM; Brunk-UT; Olsson-AG. Arterioscler-Thromb-Vasc-Biol. 1995 Sep; 15(9): 1345-51.
Athletes
Athletes
Athletes face an increased risk for iron deficiency and may benefit from supplementation, according to this article. The authors feel that enough evidence has been presented to support controlled iron supplementation in all athletes with low serum ferritin levels. Firstly, the development of iron deficiency is prevented. Secondly, the nonspecific upregulation of intestinal metal ion absorption is reverted to normal, thus limiting the hyperabsorption of potentially toxic lead and cadmium even in individuals with mild iron deficiency.
Nielsen P Nachtigall D: Iron supplementation in athletes. Current recommendations, Sports-Med. 1998 Oct; 26(4): 207-16 1998
Atherosclerosis & Iron
Atherosclerosis
Oxidation of low density lipoproteins (LDL) in blood vessel walls plays a significant role in the development of atherosclerosis. LDL oxidation in vitro is greatly accelerated by the presence of "catalytic" iron or copper ions, which have already been shown to be present within advanced atherosclerotic lesions.
Mechanical damage to human arterial wall samples (both normal and early or intermediate atherosclerotic lesions) causes release of "catalytic" iron and copper ions, to an extent increasing with the damage.
Traumatic (e.g. during angioplasty), or other, injury to the vessel wall may contributes to the generation of metal ions that can facilitate LDL oxidation and other free radical reactions, so promoting atherosclerosis.
Metal ion release from mechanically-disrupted human arterial wall. Implications for the development of atherosclerosis. Evans-PJ; Smith-C; Mitchinson-MJ; Halliwell-B. Free-Radic-Res. 1995 Nov; 23(5): 465-9.
Atherosclerotic
Atherosclerotic
Low density lipoproteins are highly sensitive to oxidation by copper salts, and such peroxidation is accompanied by macrophage scavenger receptor recognition. This study shows that fresh human atherosclerotic material (aneurysms and endarterectomies) can contain detectable amounts of redox active iron and copper that is chelatable from tissue homogenates. Such material is often prooxidant towards lipid peroxidation and deoxyribose degradation. Aneurysms and endarterectomies contain ferroxidase 1 activities.
Prooxidant iron and copper, with ferroxidase and xanthine oxidase activities in human atherosclerotic material. Swain-J; Gutteridge-JM. FEBS-Lett. 1995 Jul 24; 368(3): 513-5.
Balance
Balance
Under normal circumstances, most of the lumenal iron taken into the intestinal mucosal cell is stored within the cell as ferritin and subsequently is lost in the faeces when the cell exfoliates at the end of its lifespan.
Administration of oral or parenteral iron to patients with iron deficiency led to a prompt rise in both forms of faecal ferritin, although the relative increase of L-rich ferritin was greater than that of H-rich ferritin with oral iron administration. Faecal ferritin correlated closely with iron stores in normals and patients with iron deficiency .
Ferritin excretion and iron balance in humans. Skikne-BS; Whittaker-P; Cooke-A; Cook-JD. Br-J-Haematol. 1995 Jul; 90(3): 681-7.
Bioavailability
Bioavailability
Several dietary factors affect the bioavailability of dietary iron and iron stores, according to this study conducted on 634 elderly people (ages 67-93). The study measured iron stores through serum ferritin testing, and dietary components through a food-frequency questionairre. Heme iron, supplemental iron, dietary vitamin C, and alcohol were positively associated with serum ferritin, whereas coffee intake had a negative association. Sex was a strong predictor of serum ferritin--women having significantly lower mean concentrations than men.
Burton, G.W. Traber, M.G. Acuff, R.V. Walters, D.N. Kayden, H. Hughes, L. Ingold, K.U: Dietary determinants of iron stores in a free-living elderly population: The Framingham Heart Study, Am-j-clin-nutr. Bethesda, Md. : American Society for Clinical Nutrition. Apr 1998. v. 67 (4) p. 722-733. 1998
Blood donations
Blood donations
Assessed changes in iron stores and iron absorption after repeat blood donations using a combination of biochemical measures of iron status: ferritin, hemoglobin, and transferrin saturation.
Decreases in iron stores in supplemented men were not significantly different from those in nonsupplemented men. Nonsupplemented women showed a significantly greater decline in iron stores than did supplemented women. Mean maximal iron absorption was approximately 4.10 mg/d for men and approximately 3.55 mg/d for women regardless of iron intake.
Iron stores and iron absorption: effects of repeated blood donations. Garry-PJ; Koehler-KM; Simon-TL. Am-J-Clin-Nutr. 1995 Sep; 62(3): 611-20.
Calcium
Calcium
Increased intake of calcium has been recently recommended by a National Institutes of Health (NIH) Consensus Development Panel on Optimal Calcium Intake. However, high intakes of dietary calcium can inhibit iron absorption if both are present in the same meal. The mechanism for the calcium-iron interaction is not known. A recent study has demonstrated that separating foods high in calcium from meals high in iron can prevent some of the calcium-induced inhibition of iron absorption. The feasibility of changing the nature of meals or the timing of calcium supplementation to adjust for this phenomenon is untested.
The inhibitory effect of dietary calcium on iron bioavailability: a cause for concern? Whiting-SJ. Nutr-Rev. 1995 Mar; 53(3): 77-80.
Chelators
Chelators
The efficacy and toxicity aspects of the iron and aluminium chelating drugs desferrioxamine and deferiprone (L1, 1,2-dimethyl-3-hydroxypyrid-4-one), have been compared. Major emphasis was given to conditions of iron overload, imbalance and toxicity, as well as the incidence and possible causes of toxic side effects in both animals and humans.
Overall, oral deferiprone appears to be as effective as s.c. desferrioxamine in the removal of iron and aluminium in man and to have a similar but different toxicity profile from desferrioxamine in both animals and man. The low cost and oral activity of deferiprone will make it the drug of choice.
Comparative efficacy and toxicity of desferrioxamine, deferiprone and other iron and aluminium chelating drugs. Kontoghiorghes-GJ. Toxicol-Lett. 1995 Oct; 80(1-3): 1-18.
Colorectal cancer
Colorectal cancer
According to the author of this study, the benefits of iron supplementation should be carefully compared to the potential cancer risks involved in long-term iron exposure. The author reviewed 33 comparative studies that assessed iron exposure in people with and without colorectal neoplastic lesions. In these studies, iron exposure was measured in terms of dietary iron intake, iron vitamin supplementation, body iron stores, and gene status for hereditary hemochromatosis. Three-quarters of the larger comparative studies found a correlation between increased iron exposure and increased risk of developing colorectal cancer.
Nelson RL: Iron and colorectal cancer risk: human studies, Nutr Rev 2001 May;59(5):140-8
Iron, in excess, may cause free-radical buildup in the colon, thereby leading to an increased risk for colorectal cancer, according to this study conducted on 18 men and women. The researchers found that most of the excess iron given to the participants was not absorbed, and free radical production increased dramatically after supplementation, as tested by the participants' waste. These free radicals may cause gene mutations, which could lead to carcinogenesis. People who have a high iron intake (large amounts of red meat, for example) have exhibited more colon cancer than people with low iron intake.
Lund, Elizabeth, PhD: American Journal of Clinical Nutrition, 1999 Feb; 69:250-5
Deficiency/fortification
Deficiency/fortification
Iron fortification for many common foods may greatly reduce the risk of iron deficiency, which affects about 20% of the world population. The symptoms of iron deficiency include impaired physical and intellectual performance. Food-iron fortification has successfully reduced iron deficiency in many trials and is much cheaper than individual iron supplementation. The authors note many methods of fortifying food with iron - pantry staples (salt, sugar, spices) may be fortified, and haem iron can be used to fortify cereal-based food staples in developing countries such as tortillas or chappaties.
Schumann K Elsenhans B Maurer A: Iron supplementation, J-Trace-Elem-Med-Biol. 1998 Nov; 12(3): 129-40 1998
Endometriosis
Endometriosis
To show that raised iron levels in the peritoneal fluid (PF) of patients with endometriosis catalyze free radical reactions that results in the tissue destruction and fibrosis seen in these patients.
Controlling for the phase of the menstrual cycle, significantly higher levels of iron were seen in patients with endometriosis, the levels being correlated with the severity of the disease.
Results suggest that raised iron levels in the PF do not play a role in catalyzing free radical reactions as judged by the degree of lipid peroxidation.
De novo formation of adhesions in endometriosis: the role of iron and free radical reactions. Arumugam-K; Yip-YC. Fertil-Steril. 1995 Jul; 64(1): 62-4.
Erythropoiesis
Erythropoiesis
The decrease in haemoglobin concentration commonly observed after major surgery is usually corrected by red cell transfusions or oral iron medication. The increased awareness of blood-transmissible diseases has led to the restrictive use of homologous blood and to interest in alternatives for correcting anaemia.
Haemoglobin, iron, transferrin, and ferritin concentrations were not influenced by iron therapy during the postoperative period and no differences of erythropoietic and iron variables were observed between transfused and non-transfused patients. In conclusion, post-operative erythropoiesis is associated with an inflammatory effect of surgery on iron metabolism, which can explain, despite a slightly increased production of erythropoietin, the persistence of anaemia and the lack of effect of iron supplementation after surgery.
Post-operative erythropoiesis is limited by the inflammatory effect of surgery on iron metabolism. Biesma-DH; Van-de-Wiel-A; Beguin-Y; Kraaijenhagen-RJ; Marx-JJ. Eur-J-Clin-Invest. 1995 Jun; 25(6): 383-9.
Exercise & Iron
Exercise
The impact of long-term (6-month) moderate exercise on the iron status of previously sedentary women was determined.
Subjects had depleted iron stores throughout the study as indicated by their serum ferritin levels (< 15 ng.ml-1). Serum iron, total iron binding capacity and transferrin saturation were not compromised with exercise. Mean hemoglobin level in the Placebo/Ex group was significantly lower than the 50 Fe/Ex and the Meat/Ex groups by week 24. However, changes in serum albumin, haptoglobin, and erythropoietin data from the study cannot explain these changes.
Effects of long-term moderate exercise on iron status in young women. Rajaram-S; Weaver-CM; Lyle-RM; Sedlock-DA; Martin-B; Templin-TJ; Beard-JL; Percival-SS. Med-Sci-Sports-Exerc. 1995 Aug; 27(8): 1105-10.
Hemodialysis
Hemodialysis
Iron deficiency is common in hemodialysis patients, particularly if they are on recombinant human erythropoietin (rHuEPO) therapy.
Iron therapy resulted in a rapid elevation in serum transferrin iron saturation but it decreased to pre-treatment levels within 2 weeks after discontinuation of iron therapy. Serum ferritin concentration increased during iron therapy. In spite of this only 4 patients (2 rHuEPO treated) responded and had a hemoglobin increment > 10 g/l.
Iron availability is transiently improved by intravenous iron medication in patients on chronic hemodialysis. Rosenlof-K; Kivivuori-SM; Gronhagen-Riska-C; Teppo-AM; Slimes-MA. Clin-Nephrol. 1995 Apr; 43(4): 249-55.
Hepatitis
Hepatitis
Recent evidence suggests that patients with chronic hepatitis C virus (CHCV) who respond to interferon-alpha (IFN) therapy have a lower hepatic iron concentration than those who do not.
Iron deposition in sinusoidal cells and portal tracts is significantly less frequent in patients with complete response to IFN than in those with poor or no response, and may be a useful, objective predictor of response to IFN therapy.
Distribution of iron in the liver predicts the response of chronic hepatitis C infection to interferon therapy [published erratum appears in Am J Clin Pathol 1995 Aug;104(2):232] Barton-AL; Banner-BF; Cable-EE; Bonkovsky-HL. Am-J-Clin-Pathol. 1995 Apr; 103(4): 419-24.
Hepatocellular carcinoma
Hepatocellular carcinoma
Iron was systematically studied in the nontumorous liver of 24 patients with hepatocellular carcinoma (HCC) developed on a noncirrhotic liver.
Shows a mild but unquestionable parenchymal iron excess in the nontumorous liver of most patients. Must take into account and to treat any liver iron excess, even when mild.
Increased liver iron stores in patients with hepatocellular carcinoma developed on a noncirrhotic liver. Turlin-B; Juguet-F; Moirand-R; Le-Quilleuc-D; Loreal-O; Campion-JP; Launois-B; Ramee-MP; Brissot-P; Deugnier-Y. Hepatology. 1995 Aug; 22(2): 446-50.
Inflammation
Identified morphological parameters of benign prostatic hyperplastic inflammation that correlate with pre-biopsy prostate specific antigen (PSA) concentrations.
A total of 66 patients with exclusively benign prostatic tissue on prostate biopsies was analyzed. Difference between inflammation graded groups was not significant when considering serum or urinary PSA. There was a significant correlation between aggressiveness grading and serum PSA, whereas aggressiveness grading and urinary PSA did not correlate.
Prostatic subclinical inflammation is not associated with high urinary PSA. Unless associated with glandular epithelial disruption, density of prostatic interstitial inflammatory cell infiltrate is not significantly correlated with serum PSA concentration.
This issue should be considered when interpreting a prostate biopsy.
Irani J et al., Inflammation in benign prostatic hyperplasia: correlation with prostate specific antigen value. J Urol, 1997 Apr, 157:4, 1301-3.
LDL cholesterol & Iron
LDL cholesterol
High amounts of dietary iron contribute to the oxidation of low-density lipoprotein (LDL) cholesterol, thereby enabling it to participate in the atherosclerotic process, according to this study conducted on rats. Rats received diets differing only in iron concentration: 35 mg/kg, 150 mg/kg or 300 mg/kg diet. Dietary iron increased LDL-VLDL lipid peroxidation, protein modification, agarose migration distance and band width as well as cholesterol/protein ratio. Increased quantities of dietary iron led to a higher degree of oxidative change in LDL-VLDL. The researchers suggest that these oxidative changes may be prevented by supplementation with antioxidants.
Van Jaarsveld H Pool GF Barnard HC: Dietary iron concentration alters LDL oxidatively. The effect of antioxidants, Res-Commun-Mol-Pathol-Pharmacol. 1998 Jan; 99(1): 69-80 1998
Meat diets
Meat diets
The effects of three diets--high meat (HM), low meat (LM), or low meat with mineral supplements (LS)--on zinc absorption, elemental balance, and related clinical indexes were investigated in a metabolic study of older women
The HM diet was unexpectedly associated with lower iron status (higher iron-binding capacity and lower ferritin than LM and LS diets). These results indicate that 0.8 g protein/kg body wt meets protein requirements and that high meat consumption increases zinc retention without compromising calcium status and may reduce indexes of iron status.
High- versus low-meat diets: effects on zinc absorption, iron status, and calcium, copper, iron, magnesium, manganese, nitrogen, phosphorus, and zinc balance in postmenopausal women. Hunt-JR; Gallagher-SK; Johnson-LK; Lykken-GI. Am-J-Clin-Nutr. 1995 Sep; 62(3): 621-32.
Menstruation
Menstruation
Determining iron balance in menstruating women by examining the relationships between total iron requirements, based on menstrual iron losses and basal iron losses, and serum ferritin concentration, transferrin saturation, blood haemoglobin concentration, bone marrow haemosiderin and absorption of iron from a test dose of ferrous sulphate (0.56 mg Fe).
A prevalence of iron deficiency of about 25%. The continuous regulation of iron absorption from iron deficiency to iron repletion has a critical balance point determined by the properties of the diet.
Iron balance in menstruating women. Hallberg-L; Hulthen-L; Bengtsson-C; Lapidus-L; Lindstedt-G. Eur-J-Clin-Nutr. 1995 Mar; 49(3): 200-7.
Metabolism & Iron
Metabolism
Ferric iron is bound to mucin in the stomach and delivered to the duodenum where it can be absorbed. Iron is transported across the apical membrane of the gut mucosa by integrin. Once within the mucosal cell, iron may be stored, utilized in protein synthesis, or exported to the serum.
In the serum, iron is carried by transferrin. Diferric transferrin binds to transferrin receptor on the surface of cells and is endocytosed.
In the cell, iron is bound to high and low molecular weight ligand and is thought to shuttle iron within the cell. Iron can be stored intracellularly within ferritin, or can be utilized in a number of iron containing proteins synthesized by the mitochondrion, including heme, aconitase, and cytochromes.
The first chain of enzymes in the biosynthesis of heme is erythroid 5-aminolevulinate synthase (eALAS).
Intracellular iron concentration regulates the synthesis of ferritin, transferrin receptor, and eALAS, thus controlling our iron metabolism. Iron regulates these proteins post-transcriptionally via iron responsive elements (IRE), which are highly conserved stem-loop structures found in messenger ribonucleic acid (mRNA), and an IRE binding protein (IRE-BP), which responds to increased intracellular iron concentrations by binding the IRE, and repressing mRNA translation or stabilizing the mRNA, depending on whether the IRE is located in the upstream or downstream untranslated regions of the mRNA.
Cellular responses to iron depletion and iron over-load can be explained in terms of these regulatory mechanisms.
Iron metabolism and its regulation. A review. Lash-A; Saleem-A. Ann-Clin-Lab-Sci. 1995 Jan-Feb; 25(1): 20-30.
Neurological disorders
Neurological disorders
Iron is one of few metal ions whose role in the central nervous system has received little attention, even though it is important in many enzymatic, metabolic and structural processes. The brain is rich in iron, and iron is the most likely initiator of free oxygen radicals generation. Iron-generated free radicals play an important role in the pathogenesis of many neurological disorders. Experimental studies have shown that iron chelators and free-radical scavengers may have an important therapeutic potential in the future trends of treatment.
[The role of iron in the pathology of nervous system] Tynecka-M. Neurol-Neurochir-Pol. 1995 May-Jun; 29(3): 409-17.
Akathisia
Akathisia
An association found between akathisia and iron deficiency led to the suggestion that iron supplementation might be a useful therapeutic intervention for patients with akathisia. There is, however, a body of literature on the abnormal deposition of iron in the brain in several degenerative diseases like Hallervorden-Spatz syndrome, Parkinson's disease, and Alzheimer's disease.
Given the ability of neuroleptics to chelate iron and promote its deposition in the brain, we questioned whether peripheral measures of iron are an accurate reflection of central iron levels and thus whether there was a rationale for iron supplementation in akathisia.
There is a relationship between iron excess in the basal ganglia and the movement disorders.
The rationale for iron supplementation in the treatment of akathisia is relatively weak, and there are potentially adverse long-term consequences.
Is there a rationale for iron supplementation in the treatment of akathisia? A review of the evidence. Gold-R; Lenox-RH. J-Clin-Psychiatry. 1995 Oct; 56(10): 476-83.
Alzheimer's
Alzheimer's
Alzheimer's disease may be caused by free radical damage to membranes of endocytic vesicles due to defective binding of iron and aluminium by Tf C2. The aluminium binds to the membranes, creating pores, while the iron reacts with H2O2 and superoxide radicals produced by activated microglia (brain phagocytes), to produce hydroxyl radicals (oxidative toxins), which attack the fatty acids in the membranes through these pores. In order to treat the disease successfully, it would be necessary to alleviate the multiple deficiencies caused by these toxins by constantly providing the cells with antioxidants and other essential nutrients. In addition, a drug that would stimulate the regrowth of neurons is needed.
Transferrin C2 and Alzheimer's disease: another piece of the puzzle found? Van-Rensburg-SJ; Carstens-ME; Potocnik-FC; van-der-Spuy-G; van-der-Walt-BJ; Taljaard-JJ. Med-Hypotheses. 1995 Apr; 44(4): 268-72.
Alzheimer's & Parkinson's
Alzheimer's & Parkinson's
Oxidant-mediated damage is suspected to be involved in the pathogenesis of several neurodegenerative disorders. Iron promotes conversion of hydrogen peroxide to hydroxyl radical and, thus, may contribute to oxidant stress.
Iron was significantly increased in Alzheimer's disease globus pallidus and frontal cortex and Parkinson's disease globus pallidus, and transferrin was significantly increased in Alzheimer's disease frontal cortex, compared with elderly controls. The transferrin/iron ratio, a measure of iron mobilization capacity, was decreased in globus pallidus and caudate in both disorders.
The altered relationship between iron and transferrin provides further evidence that a disturbance in iron metabolism may be involved in both disorders.
Transferrin and iron in normal, Alzheimer's disease, and Parkinson's disease brain regions. Loeffler-DA; Connor-JR; Juneau-PL; Snyder-BS; Kanaley-L; DeMaggio-AJ; Nguyen-H; Brickman-CM; LeWitt-PA. J-Neurochem. 1995 Aug; 65(2): 710-24.
Lipid peroxidation
Lipid peroxidation
Iron and lipid peroxidation are believed to be involved in the degeneration of pigmented neurons in Parkinson's disease. Melanin-iron interaction is thought to play a role in iron accumulation and reactivity.
Examine antioxidant properties of isolated natural and synthetic neuromelanin.
Melanin had a distinct protective effect on lipid peroxidation induced by ferrous ions or water-soluble free-radical initiator but was relatively inefficient when peroxidation was initiated with lipid-soluble compound.
Strongly support the idea that neuromelanin of pigmented neurons can act as a natural antioxidant by sequestering redox-active metal ions.
Antioxidant action of neuromelanin: the mechanism of inhibitory effect on lipid peroxidation. Korytowski-W; Sarna-T; Zar-ba-M. Arch-Biochem-Biophys. 1995 May 10; 319(1): 142-8.
Parkinson's
Parkinson's
The substantia nigra and globus pallidus (two iron-rich brain areas) receive a substantial innervation from the neostriatum, a considerable amount of which is GABAergic. Because of this anatomic relationship and the finding that prevention of GABA degradation in these two areas decreases their histochemical levels of iron, GABAergic transmission/metabolism may be important in regulating brain iron levels.
Investigated the effects of denervation of striatal/pallidal inputs to globus pallidus/substantia nigra on iron levels and associated pathologic changes in globus pallidus/substantia nigra.
Results suggest that loss or dysfunction of striatonigral/striatopallidal GABAergic neurons in several neurodegenerative diseases (including Hallervorden-Spatz syndrome, progressive supranuclear palsy, multiple system atrophy, and Parkinson's disease) may result in an increase or redistribution of nigral iron to cause loss of substantia nigra neurons.
Time-dependent changes in iron levels and associated neuronal loss within the substantia nigra following lesions within the neostriatum/globus pallidus complex. Sastry-S; Arendash-GW. Neuroscience. 1995 Aug; 67(3): 649-66.
Elevated iron levels in the substantia nigra (SN) of the brain in Parkinson's disease (PD) may mediate lipid peroxidative reactions, promoting SN neuronal death.
Correlations with motor performance in PD suggest that the clinical severity of PD may be related to SN iron accumulation.
Increased iron-related MRI contrast in the substantia nigra in Parkinson's disease [published erratum appears in Neurology 1995 Jul;45(7):1420] Gorell-JM; Ordidge-RJ; Brown-GG; Deniau-JC; Buderer-NM; Helpern-JA. Neurology. 1995 Jun; 45(6): 1138-43.
To determine the changes in basal ganglia iron content associated with various stages of idiopathic Parkinson's disease. DESIG
Patients with Parkinson's disease exhibited significantly decreased T2 relaxation time in the pars compacta of the substantia nigra compared with controls regardless of disease duration. Patients with a duration of illness above 10 years (n = 12) exhibited significantly increased T2 relaxation time in the anterior and posterior putamen (P < .005 and P < .01, respectively) and in the pallidum compared with age-matched controls. Putamental T2 relaxation time positively correlated with disease duration.
More complex brain iron changes than those previously reported are associated with idiopathic Parkinson's disease, including increased nigral iron content and decreased putamenal and pallidal iron concentration in patients with a duration of illness above 10 years.
Magnetic resonance imaging evidence of decreased putamenal iron content in idiopathic Parkinson's disease. Ryvlin-P; Broussolle-E; Piollet-H; Viallet-F; Khalfallah-Y; Chazot-G. Arch-Neurol. 1995 Jun; 52(6): 583-8.
Oxidative DNA damage
Oxidative DNA damage
The conventional model of oxidative DNA damage posits a role for superoxide (O2-) as a reductant for iron, which subsequently generates a hydroxyl radical by transferring the electron to H2O2. The hydroxyl radical then attacks DNA.
Experiments with iron transport mutants confirmed that increases in free-iron concentration have the effect of accelerating DNA oxidation.
Superoxide and the production of oxidative DNA damage. Keyer-K; Gort-AS; Imlay-JA. J-Bacteriol. 1995 Dec; 177(23): 6782-90.
Pregnancy
Pregnancy
To determine the rate of iron deficiency in women coming for antenatal care and to asses whether the haemoglobin concentration is a good index in its detection.
In women attending for antenatal care the rate of iron deficiency is high (69%). The haemoglobin concentration is not a good index to detect this.
Iron stores and its correlation to haemoglobin levels in pregnant women attending an antenatal clinic. Goonewardene-M; Seekkuge-J; Liyanage-C. Ceylon-Med-J. 1995 Jun; 40(2): 67-9.
Prenatal vitamins
Prenatal vitamins
Iron absorption varies in relation to the other components of prenatal vitamins, according to this study, which measured the bioavailability of iron in four popular prenatal multivitamin/multimineral supplements. The prenatal formulations were Natalins Rx, Prenatal 1/1, Stuartnatal Plus and Prenate 90. One-A-Day (without iron) was included in the study for the control group. The descending order of absorption, both fasting and postprandial, were Prenate 90, Stuartnatal Plus, Prenatal 1/1 and Natalins Rx. The observed differences in iron absorption between prenatal supplements apparently reflect the effects of the various combinations of vitamins, essential minerals and additives.
Dawson EB Dawson R Behrens J DeVora MA McGanity WJ: Iron in prenatal multivitamin/multimineral supplements. Bioavailability, J-Reprod-Med. 1998 Feb; 43(2): 133-40 1998
Renal insufficiency
Renal insufficiency
Examines the serum aluminum (Al) and daily urine Al excretion in patients (#50) with chronic renal insufficiency (CRI) not taking any Al-containing agents. The
Al tends to be accumulated in patients with CRI, similar to Al in patients with hemodialysis, and the chronic low-level Al exposure in CRI patients may affect body iron status and metabolism, or iron status may play a role in Al absorption and excretion.
Relationship of body iron status and serum aluminum in chronic renal insufficiency patients not taking any aluminum-containing drugs. Lin-JL; Lim-PS; Leu-ML. Am-J-Nephrol. 1995; 15(2): 118-22.
Selenium (Rats)
Selenium (Rats)
There are hematological abnormalities in selenium (Se)-deficient animals.
Se deficiency may cause a secondary overload of iron and unbalanced distribution of other minerals.
Selenium deficiency as a cause of overload of iron and unbalanced distribution of other minerals.
Chareonpong-Kawamoto-N; Yasumoto-K. Biosci-Biotechnol-Biochem. 1995 Feb; 59(2): 302-6.
Vegetarians
Vegetarians
The iron status of young Chinese Buddhist vegetarians. A characteristic of the vegetarian diet in this study was the replacement of meat by soybean products. Results of the dietary assessment showed that the average iron density of the diets ranged from 1.9 to 2.2 mg/MJ, with no difference between the vegetarian and nonvegetarian diets.
Daily iron intake was similar in both vegetarian and nonvegetarian men. However, iron intake was significantly higher in female vegetarians than nonvegetarians, averaging 104 and 78% of the RDA, respectively.
Results of blood analysis showed that, for both sexes, the median plasma ferritin concentration of the vegetarians (male 47 micrograms/L and female 12 micrograms/L) was about half the level of the nonvegetarians (male 91 micrograms/L and female 27 micrograms/L). Occurrence and risk of iron deficiency are more prevalent in vegetarians.
A vegetarian diet that is rich in soybean products and restricted in animal foods is limited in bioavailable iron and is not adequate for maintaining iron balance in men and women.
A vegetarian diet rich in soybean products compromises iron status in young students. Shaw-NS; Chin-CJ; Pan-WH. J-Nutr. 1995 Feb; 125(2): 212-9.
Vitamin C
Thirteen healthy male subjects were evaluated for the ability of ascorbic acid to clear plasma alcohol levels. .5 and .8 g/kg body weight of alcohol were utilized and blood samples were taken at 0, .5 and then every 6 hours after alcohol consumption to assess plasma alcohol, ascorbic acid levels, RBC glutathione levels and plasma alanine aminotransferase activity.
Pretreatment with ascorbic acid short and long term resulted in a significantly enhanced clearance of alcohol. There was no significant effect on red cell reduced glutathione concentrations or plasma alanine aminotransferase activity. Subjects were used as their own controls and were studied three times. The first was with no ascorbic acid supplementation. The second was with two grams of ascorbic acid given orally 1 hour before alcohol consumption and the third was two grams (500 mg 4 times daily) of ascorbic acid for two weeks with the last dose of the vitamin taken the night before the test.
Long term vitamin C supplementation resulted in better alcohol clearance. Ascorbic acid may work by functioning as an electron donor sparing the NAD/NADH system and accelerating the conversion of alcohol to its metabolites.
"Effect of Ascorbic Acid on Plasma Alcohol Clearance", Chen, Marianne F., ScD, et al, Journal of The American College of Nutrition, 1990;9(3):185-189.
Inflammatory Bowel Disease & Iron
Inflammatory Bowel Disease
While many patients with inflammatory bowel disease experience iron deficiency, supplementation with iron may lead to increased inflammation due to formation of reactive oxygen species, according to this review article. The author indicates that anemia during inflammatory bowel disease results from both iron deficiency and decreased erythropoiesis (red blood cell formation). However, treatment of iron deficiency requires iron supplementation, which, according to some animal studies, may lead to increased inflammation. The author calls for further research into this area, to determine if iron supplementation affects human subjects in the same way.
Oldenburg B, et al: Iron and inflammatory bowel disease, Aliment Pharmacol Ther 2001 Apr;15(4):429-38
Language and Motor Skill Development
Language and Motor Skill Development
Iron sufficiency may be essential for proper language and motor skill development, according to this double- blind, placebo-controlled study of 614 preschool children in Zanzibar. Most of the children suffered from anemia and worm infections before they were given iron supplements. After intervention, their iron status was significantly improved, and a subsequent improvement in language development was seen. Iron supplementation also improved motor development in children who had hemoglobin concentrations lower than 90 g/l prior to intervention. Routine treatment against worms also correlated with positive effects, but none were statistically significant.
Stoltzfus R, et al: Effects of iron supplementation and anthelmintic treatment on motor and language development of preschool children in Zanzibar: double-blind, placebo controlled study, BMJ 2001 December 15;323:1389
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