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Buerkli S, Salvioni L, Koller N, Zeder C, Teles MJ, Porto G, Habermann JH, Dubach IL, Vallelian F, Frey BM, Moretti D, Baumgartner J, Zimmermann MB. The effect of a natural polyphenol supplement on iron absorption in adults with hereditary hemochromatosis. Eur J Nutr 2022; 61:2967-2977. [PMID: 35320401 PMCID: PMC9363374 DOI: 10.1007/s00394-022-02829-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 02/04/2022] [Indexed: 11/29/2022]
Abstract
Objectives We developed a natural polyphenol supplement that strongly chelates iron in vitro and assessed its effect on non-heme iron absorption in patients with hereditary hemochromatosis (HH). Methods We performed in vitro iron digestion experiments to determine iron precipitation by 12 polyphenol-rich dietary sources, and formulated a polyphenol supplement (PPS) containing black tea powder, cocoa powder and grape juice extract. In a multi-center, single-blind, placebo-controlled cross-over study, we assessed the effect of the PPS on iron absorption from an extrinsically labelled test meal and test drink in patients (n = 14) with HH homozygous for the p.C282Y variant in the HFE gene. We measured fractional iron absorption (FIA) as stable iron isotope incorporation into erythrocytes. Results Black tea powder, cocoa powder and grape juice extract most effectively precipitated iron in vitro. A PPS mixture of these three extracts precipitated ~ 80% of iron when 2 g was added to a 500 g iron solution containing 20 µg Fe/g. In the iron absorption study, the PPS reduced FIA by ~ 40%: FIA from the meal consumed with the PPS was lower (3.01% (1.60, 5.64)) than with placebo (5.21% (3.92, 6.92)) (p = 0.026)), and FIA from the test drink with the PPS was lower (10.3% (7.29 14.6)) than with placebo (16.9% (12.8 22.2)) (p = 0.002). Conclusion Our results indicate that when taken with meals, this natural PPS can decrease dietary iron absorption, and might thereby reduce body iron accumulation and the frequency of phlebotomy in patients with HH. Trial registry: clinicaltrials.gov (registration date: 9.6.2019, NCT03990181). Supplementary Information The online version contains supplementary material available at 10.1007/s00394-022-02829-8.
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Affiliation(s)
- Simone Buerkli
- Laboratory of Human Nutrition, Institute of Food Nutrition and Health, Department of Health Science and Technology, Swiss Federal Institute of Technology (ETH Zurich), LFV D27.2, Schmelzbergstrasse 7, CH8092, Zurich, Switzerland.
| | - Laura Salvioni
- Laboratory of Human Nutrition, Institute of Food Nutrition and Health, Department of Health Science and Technology, Swiss Federal Institute of Technology (ETH Zurich), LFV D27.2, Schmelzbergstrasse 7, CH8092, Zurich, Switzerland
| | - Natalie Koller
- Laboratory of Human Nutrition, Institute of Food Nutrition and Health, Department of Health Science and Technology, Swiss Federal Institute of Technology (ETH Zurich), LFV D27.2, Schmelzbergstrasse 7, CH8092, Zurich, Switzerland
| | - Christophe Zeder
- Laboratory of Human Nutrition, Institute of Food Nutrition and Health, Department of Health Science and Technology, Swiss Federal Institute of Technology (ETH Zurich), LFV D27.2, Schmelzbergstrasse 7, CH8092, Zurich, Switzerland
| | - Maria José Teles
- Clinical Pathology, S. João University Hospital Center, Porto, Portugal
| | - Graça Porto
- Clinical Hematology, Santo António Hospital, Porto University Hospital Center (CHUP), Porto, Portugal.,Abel Salazar Institute for Biomedical Sciences (ICBAS), Porto, Portugal.,Institute of Research and Innovation in Health Sciences (i3S) of the University of Porto, Porto, Portugal
| | | | - Irina Léa Dubach
- Division of Internal Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Florence Vallelian
- Division of Internal Medicine, University Hospital of Zurich, Zurich, Switzerland
| | - Beat M Frey
- Blood Transfusion Service, Swiss Red Cross, Schlieren, Switzerland
| | - Diego Moretti
- Laboratory of Human Nutrition, Institute of Food Nutrition and Health, Department of Health Science and Technology, Swiss Federal Institute of Technology (ETH Zurich), LFV D27.2, Schmelzbergstrasse 7, CH8092, Zurich, Switzerland.,Department of Health, Swiss Distance University of Applied Sciences, Regensdorf/Zurich, Switzerland
| | - Jeannine Baumgartner
- Laboratory of Human Nutrition, Institute of Food Nutrition and Health, Department of Health Science and Technology, Swiss Federal Institute of Technology (ETH Zurich), LFV D27.2, Schmelzbergstrasse 7, CH8092, Zurich, Switzerland
| | - Michael B Zimmermann
- Laboratory of Human Nutrition, Institute of Food Nutrition and Health, Department of Health Science and Technology, Swiss Federal Institute of Technology (ETH Zurich), LFV D27.2, Schmelzbergstrasse 7, CH8092, Zurich, Switzerland
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Cepeda-Lopez AC, Allende-Labastida J, Melse-Boonstra A, Osendarp SJ, Herter-Aeberli I, Moretti D, Rodriguez-Lastra R, Gonzalez-Salazar F, Villalpando S, Zimmermann MB. The effects of fat loss after bariatric surgery on inflammation, serum hepcidin, and iron absorption: a prospective 6-mo iron stable isotope study. Am J Clin Nutr 2016; 104:1030-1038. [PMID: 27557657 DOI: 10.3945/ajcn.115.115592] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2015] [Accepted: 07/22/2016] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Iron deficiency is common in obese subjects. This may be due to an increase in serum hepcidin and a decrease in iron absorption from adiposity-related inflammation. OBJECTIVE We evaluated whether weight and fat loss in obese subjects would decrease inflammation and serum hepcidin and thereby improve iron absorption. DESIGN We performed a 6-mo prospective study in obese [body mass index (in kg/m2) ≥35 and <45] adults who had recently undergone laparoscopic sleeve gastrectomy. At 2 and 8 mo postsurgery, subjects consumed a test drink with 6 mg 57Fe as ferrous sulfate and were intravenously infused with 100 μg 58Fe as iron citrate. We then compared erythrocyte incorporation of iron isotopic labels, changes in body composition, iron status, hepcidin, and inflammation at each time point. RESULTS Forty-three subjects were studied at baseline, and 38 completed the protocol (32 women and 6 men). After 6 mo, total body fat, interleukin IL-6, and hepcidin were significantly lower (all P < 0.005). In iron-deficient subjects (n = 17), geometric mean (95% CI) iron absorption increased by 28% [from 9.7% (6.5%, 14.6%) to 12.4% (7.7%, 20.1%); P = 0.03], whereas in iron-sufficient subjects (n = 21), absorption did not change [5.9% (4.0%, 8.6%) and 5.6% (3.9%, 8.2%); P = 0.81]. CONCLUSION Adiposity-related inflammation is associated with a reduction in the normal upregulation of iron absorption in iron-deficient obese subjects, and this adverse effect may be ameliorated by fat loss. This protocol was approved by the ethics committees of Wageningen University, ETH Zurich, the University of Monterrey, and the Federal Commission for the Protection against Sanitary Risks, and registered at clinicaltrials.gov as NCT01347905.
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Affiliation(s)
- Ana C Cepeda-Lopez
- Division of Human Nutrition, Wageningen University, Wageningen, Netherlands; Health Sciences Division, University of Monterrey, Monterrey, Mexico;
| | | | | | - Saskia Jm Osendarp
- Division of Human Nutrition, Wageningen University, Wageningen, Netherlands; Micronutrient Initiative, Ottawa, Canada
| | | | | | | | | | - Salvador Villalpando
- Division of Nutrition and Health, National Institute of Public Health of Mexico, Cuernavaca, Mexico
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Lim KHC, Riddell LJ, Nowson CA, Booth AO, Szymlek-Gay EA. Iron and zinc nutrition in the economically-developed world: a review. Nutrients 2013; 5:3184-211. [PMID: 23945676 PMCID: PMC3775249 DOI: 10.3390/nu5083184] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 07/19/2013] [Accepted: 07/26/2013] [Indexed: 12/21/2022] Open
Abstract
This review compares iron and zinc food sources, dietary intakes, dietary recommendations, nutritional status, bioavailability and interactions, with a focus on adults in economically-developed countries. The main sources of iron and zinc are cereals and meat, with fortificant iron and zinc potentially making an important contribution. Current fortification practices are concerning as there is little regulation or monitoring of intakes. In the countries included in this review, the proportion of individuals with iron intakes below recommendations was similar to the proportion of individuals with suboptimal iron status. Due to a lack of population zinc status information, similar comparisons cannot be made for zinc intakes and status. Significant data indicate that inhibitors of iron absorption include phytate, polyphenols, soy protein and calcium, and enhancers include animal tissue and ascorbic acid. It appears that of these, only phytate and soy protein also inhibit zinc absorption. Most data are derived from single-meal studies, which tend to amplify impacts on iron absorption in contrast to studies that utilize a realistic food matrix. These interactions need to be substantiated by studies that account for whole diets, however in the interim, it may be prudent for those at risk of iron deficiency to maximize absorption by reducing consumption of inhibitors and including enhancers at mealtimes.
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Affiliation(s)
| | | | | | | | - Ewa A. Szymlek-Gay
- Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition Sciences, Deakin University, Burwood, Victoria 3125, Australia; E-Mails: (K.H.C.L); (L.J.R.); (C.A.N.); (A.O.B.)
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von Rosenberg SJ, Wehr UA. Lanthanum salts improve bone formation in a small animal model of post-menopausal osteoporosis. J Anim Physiol Anim Nutr (Berl) 2012; 96:885-94. [DOI: 10.1111/j.1439-0396.2012.01326.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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5
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Young MF, Griffin I, Pressman E, McIntyre AW, Cooper E, McNanley T, Harris ZL, Westerman M, O’Brien KO. Utilization of iron from an animal-based iron source is greater than that of ferrous sulfate in pregnant and nonpregnant women. J Nutr 2010; 140:2162-6. [PMID: 20980658 PMCID: PMC2981003 DOI: 10.3945/jn.110.127209] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Heme iron absorption during pregnancy and the role of hepcidin in regulating dietary heme iron absorption remains largely unexplored. The objective of this research was to examine relative differences in heme (animal based) and nonheme (ferrous sulfate) iron utilization. This study was undertaken in 18 pregnant (ages 16-32 y; wk 32-35 of gestation) and 11 nonpregnant women (ages 18-27 y). Women were randomly assigned to receive both an animal-based heme meal (intrinsically labeled (58)Fe pork) and labeled ferrous sulfate ((57)Fe) fed on alternate days. Blood samples obtained 2 wk postdosing were used to assess iron status indicators and serum hepcidin and iron utilization based on RBC incorporation of iron isotopes. Heme iron utilization was significantly greater than nonheme iron utilization in the pregnant (47.7 ± 14.4 vs. 40.4 ± 13.2%) and nonpregnant women (50.1 ± 14.8 vs. 15.3 ± 9.7%). Among pregnant women, utilization of nonheme iron was associated with iron status, as assessed by the serum transferrin receptor concentration (P = 0.003; r(2) = 0.43). In contrast, heme iron utilization was not influenced by maternal iron status. In the group as a whole, women with undetectable serum hepcidin had greater nonheme iron utilization compared with women with detectable serum hepcidin (P = 0.02; n = 29); however, there were no significant differences in heme iron utilization. Our study suggests that iron utilization from an animal-based food provides a highly bioavailable source of dietary iron for pregnant and nonpregnant women that is not as sensitive to hepcidin concentrations or iron stores compared with ferrous sulfate.
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Affiliation(s)
- Melissa F. Young
- Cornell University, Division of Nutritional Sciences, Ithaca, NY 14853
| | - Ian Griffin
- USDA/Agricultural Research Service Children’s Nutrition Research Center, Baylor College of Medicine, Houston, TX 77030
| | - Eva Pressman
- The University of Rochester School of Medicine, Rochester, NY 14642
| | | | - Elizabeth Cooper
- The University of Rochester School of Medicine, Rochester, NY 14642
| | - Thomas McNanley
- The University of Rochester School of Medicine, Rochester, NY 14642
| | - Z. Leah Harris
- Vanderbilt University Medical Center, Department of Pediatrics, Nashville, TN 37232
| | | | - Kimberly O. O’Brien
- Cornell University, Division of Nutritional Sciences, Ithaca, NY 14853,To whom correspondence should be addressed: E-mail:
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Casgrain A, Collings R, Harvey LJ, Boza JJ, Fairweather-Tait SJ. Micronutrient bioavailability research priorities. Am J Clin Nutr 2010; 91:1423S-1429S. [PMID: 20200267 DOI: 10.3945/ajcn.2010.28674a] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A micronutrient bioavailability workshop, which involved international experts and members of the scientific community and the food industry, with interactive breakout sessions based on synectics principles, was organized by the International Life Sciences Institute Europe Addition of Nutrients to Food Task Force and the European Commission Network of Excellence European Micronutrient Recommendations Aligned. After presentations by experts, a series of "challenge statements" was discussed. The aim was to address topical issues, in particular those that linked bioavailability with the derivation of micronutrient requirements and dietary recommendations, to identify gaps in knowledge and to consider research priorities. Several generic research priorities were identified, including improving the quality of dietary surveys/food composition tables, the need for more metabolic studies that use stable isotopes and high-quality longer-term interventions, and the development of multifactorial mathematical models. Among the common recurrent factors identified as important were polymorphisms/genotype, consideration of the whole diet, chemical form of the micronutrient, and the determination of physiologic requirements. The involvement of all participants in the structured discussions ensured a broad overview of current knowledge, state-of-the-art research, and consideration of priorities for future research.
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Affiliation(s)
- Amélie Casgrain
- School of Medicine, Health Policy and Practice, University of East Anglia, Norwich, United Kingdom
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Sheng XY, Hambidge KM, Miller LV, Westcott JE, Lei S, Krebs NF. Measurement of zinc absorption from meals: comparison of extrinsic zinc labeling and independent measurements of dietary zinc absorption. INT J VITAM NUTR RES 2009; 79:230-7. [PMID: 20209474 PMCID: PMC5328628 DOI: 10.1024/0300-9831.79.4.230] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Extrinsic labeling techniques are typically used to measure fractional absorption of zinc (FAZ(extrinsic)) but none have been adequately evaluated. OBJECTIVE To compare determination of the quantity of zinc absorbed (TAZ(extrinsic)) using measurements of FAZ(extrinsic) with results of simultaneous determinations of dietary zinc absorbed (TAZ(metabolic)) that are not dependent on labeling ingested food with an extrinsic tracer (modified metabolic balance technique). DESIGN (70)Zn was administered orally with all meals for 6 consecutive days to 21 healthy, free-living adult women consuming a constant diet. (68)Zn and (67)Zn were administered intravenously. FAZ(extrinsic) was measured using a dual isotope tracer ratio technique and multiplied by dietary zinc to give TAZ(extrinsic). TAZ(metabolic) was determined by addition of net absorption of zinc and endogenous fecal zinc, the latter determined by an isotope dilution technique. RESULTS TAZ(extrinsic) and TAZ(metabolic) were 3.0 +/- 1.1 mg/day and 3.1 +/- 1.1 mg/day respectively, paired t-test p = 0.492. The correlation coefficient for TAZ(extrinsic) and TAZ(metabolic) was 0.91, and for FAZ(extrinsic) and FAZ(metabolic) was 0.95. A Bland Altman analysis indicated a bias of 0.07, and the limits of agreement of -0.86 to 1.01 for TAZ(extrinsic) and TAZ(metabolic). CONCLUSION These results from two independent methods provide reasonable validation of our extrinsic labeling technique for a wide range of composite diets.
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Affiliation(s)
- Xiao-Yang Sheng
- Shanghai Jiao Tong University, School of Medicine, Xin-Hua Hospital, Department of Child and Juvenile Health Care, Shanghai, China
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8
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Relative bioavailability of micronized, dispersible ferric pyrophosphate added to an apple juice drink. Eur J Nutr 2009; 48:115-9. [DOI: 10.1007/s00394-008-0770-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2008] [Accepted: 12/07/2008] [Indexed: 12/24/2022]
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Giussani A. A recycling systemic model for the biokinetics of molybdenum radionuclides. THE SCIENCE OF THE TOTAL ENVIRONMENT 2008; 404:44-55. [PMID: 18640703 DOI: 10.1016/j.scitotenv.2008.06.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Revised: 06/02/2008] [Accepted: 06/06/2008] [Indexed: 05/26/2023]
Abstract
An overview of the available data on molybdenum biokinetics and metabolism in humans is presented, with special emphasis on the results of stable tracer studies conducted in recent years, after the publication of the systemic model for incorporated radionuclides of molybdenum recommended by the International Commission on Radiological Protection (ICRP). On the basis of the presented information, a new structure for a compartmental model of molybdenum biokinetics, including the return of material from the organs back to the systemic circulation, was developed. The structure chosen is a compromise between the attempt to provide a realistic description of the biokinetics and the need to have a simple tool for dose estimation. The model consists of two compartments associated to the extracellulare fluids (blood plasma and interstitial fluids), liver, kidneys, and one generic compartment to represent all other tissues. The possibility of a direct excretion pathway into the urine was introduced, in order to correctly describe the rapid excretion as observed in the human studies. Reference values of the model parameters have been estimated taking into consideration that the amounts of radioactive molybdenum accidentally incorporated are negligible in comparison to the daily dietary intake of stable molybdenum.
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Affiliation(s)
- Augusto Giussani
- Helmholtz Zentrum München -- German Research Center for Environmental Health, Institute of Radiation Protection, Ingolstädter Landstr. 1, 85764 Neuherberg, Germany.
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Stürup S, Hansen HR, Gammelgaard B. Application of enriched stable isotopes as tracers in biological systems: a critical review. Anal Bioanal Chem 2007; 390:541-54. [PMID: 17917720 DOI: 10.1007/s00216-007-1638-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2007] [Revised: 09/11/2007] [Accepted: 09/17/2007] [Indexed: 10/22/2022]
Abstract
The application of enriched stable isotopes of minerals and trace elements as tracers in biological systems is a rapidly growing research field that benefits from the many new developments in inorganic mass spectrometric instrumentation, primarily within inductively coupled plasma mass spectrometry (ICP-MS) instrumentation, such as reaction/collision cell ICP-MS and multicollector ICP-MS with improved isotope ratio measurement and interference removal capabilities. Adaptation and refinement of radioisotope tracer experiment methodologies for enriched stable isotope experiments, and the development of new methodologies coupled with more advanced compartmental and mathematical models for the distribution of elements in living organisms has enabled a broader use of enriched stable isotope experiments in the biological sciences. This review discusses the current and future uses of enriched stable isotope experiments in biological systems.
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Affiliation(s)
- Stefan Stürup
- Department of Pharmaceutics and Analytical Chemistry, Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, DK-2100, Copenhagen, Denmark.
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Yang XE, Chen WR, Feng Y. Improving human micronutrient nutrition through biofortification in the soil-plant system: China as a case study. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2007; 29:413-28. [PMID: 17385049 DOI: 10.1007/s10653-007-9086-0] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/07/2006] [Accepted: 02/02/2007] [Indexed: 05/08/2023]
Abstract
Micronutrient malnutrition is a major health problem in China. According to a national nutritional survey, approximately 24% of all Chinese children suffer from a serious deficiency of iron (Fe) (anemia), while over 50% show a sub-clinical level of zinc (Zn) deficiency. More than 374 million people in China suffer from goiter disease, which is related to iodine (I) deficiency, and approximately 20% of the Chinese population are affected by selenium (Se) deficiency. Micronutrient malnutrition in humans is derived from deficiencies of these elements in soils and foods. In China, approximately 40% of the total land area is deficient in Fe and Zn. Keshan and Kaschin-Beck diseases always appear in regions where the soil content of Se in low. The soil-plant system is instrumental to human nutrition and forms the basis of the "food chain" in which there is micronutrient cycling, resulting in an ecologically sound and sustainable flow of micronutrients. Soil-plant system strategies that have been adopted to improve human micronutrient nutrition mainly include: (1) exploiting micronutrient-dense crop genotypes by studying the physiology and genetics of micronutrient flow from soils to the edible parts of crops; (2) improving micronutrient bioavailability through a better knowledge of the mechanisms of the enhancers' production and accumulation in edible parts and its regulation through soil-plant system; (3) improving our knowledge of the relationship between the content and bioavailability of micronutrients in soils and those in edible crop products for better human nutrition; (4) developing special micronutrient fertilizers and integrated nutrient management technologies for increasing both the density of the micronutrients in the edible parts of plants and their bioavailability to humans.
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Affiliation(s)
- Xiao-E Yang
- MOE Key Lab, Environmental Remediation and Ecosystem Health, Zhejiang University, 310029, Hanghzou, China.
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genannt Bonsmann SS, Walczyk T, Renggli S, Hurrell RF. Oxalic acid does not influence nonhaem iron absorption in humans: a comparison of kale and spinach meals. Eur J Clin Nutr 2007; 62:336-41. [PMID: 17440529 DOI: 10.1038/sj.ejcn.1602721] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To evaluate the influence of oxalic acid (OA) on nonhaem iron absorption in humans. DESIGN Two randomized crossover stable iron isotope absorption studies. SETTING Zurich, Switzerland. SUBJECTS Sixteen apparently healthy women (18-45 years, <60 kg body weight), recruited by poster advertizing from the staff and student populations of the ETH, University and University Hospital of Zurich, Switzerland. Thirteen subjects completed both studies. METHODS Iron absorption was measured based on erythrocyte incorporation of (57)Fe or (58)Fe 14 days after the administration of labelled meals. In study I, test meals consisted of two wheat bread rolls (100 g) and either 150 g spinach with a native OA content of 1.27 g (reference meal) or 150 g kale with a native OA content of 0.01 g. In study II, 150 g kale given with a potassium oxalate drink to obtain a total OA content of 1.27 g was compared to the spinach meal. RESULTS After normalization for the spinach reference meal absorption, geometric mean iron absorption from wheat bread rolls with kale (10.7%) did not differ significantly from wheat rolls with kale plus 1.26 g OA added as potassium oxalate (11.5%, P=0.86). Spinach was significantly higher in calcium and polyphenols than kale and absorption from the spinach meal was 24% lower compared to the kale meal without added OA, but the difference did not reach statistical significance (P>0.16). CONCLUSION Potassium oxalate did not influence iron absorption in humans from a kale meal and our findings strongly suggest that OA in fruits and vegetables is of minor relevance in iron nutrition.
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Abstract
PURPOSE OF REVIEW Lifestyle, particularly dietary habits, plays a major role in the increasing prevalence of obesity, type 2 diabetes and atherosclerosis. Understanding how diet and specific foods can modify important functions of the body, in a beneficial or detrimental way, is therefore important. This review presents recent advances in the use of stable isotopes to investigate how nutrients can influence pathways of glucose, lipids and protein metabolism, and also intestinal absorption, body composition and fat mass turnover. RECENT FINDINGS Recent developments have focused mainly on the measurement of intratissular metabolic pathways, particularly in lipids and proteins. Advances in the field of cell proliferation rates, body composition and energy expenditure have also been made. Many of these developments rely on the use of deuterated water to trace multiple metabolic pathways. SUMMARY Stable isotopes can now be used to measure the kinetics and oxidation rate of circulating metabolites and also body composition, colonic fermentation, intestinal absorption, and important intratissular metabolic pathways, such as gluconeogenesis, lipogenesis, cholesterol synthesis, the turnover rate of triglycerides, individual protein synthesis and cell proliferation. Deuterated water has emerged as a powerful and versatile tool, allowing the simultaneous investigation of several aspects of protein, lipid and glucose metabolism.
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Coudray C, Feillet-Coudray C, Rayssiguier Y. Dietary inulin intake and age can significantly affect absorption of the faecal marker dysprosium in rats. Br J Nutr 2006; 95:255-9. [PMID: 16469139 DOI: 10.1079/bjn20051623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
It is believed that rare earth elements are not absorbed, and thus they are generally used in some mineral absorption studies as a faecal marker. The aim of the present study was to determine the effect of inulin intake and age on dysprosium (Dy) absorption in rats. Eighty male Wistar rats of four different ages (2, 5, 10 and 20 months) were randomised into either a control group or a group receiving 3·75% inulin in their diet for 4d and then 7·5% inulin until the end of the study. The animals were fed fresh food and waterad libitumfor 30d. The intestinal absorption of Dy was determined from a 4d (day 21 to day 25) balance study. Mean faecal Dy recovery (%) in the eight groups (3 months control, 3 months inulin, 6 months control, 6 months inulin, 11 months control, 11 months inulin, 21 months control, 21 months inulin) was 94·0 (sd 8·6), 64·8 (sd 10·1), 95·8 (sd 9·4), 81·5 (sd 12·1), 98·4 (sd 9·8), 87·8 (sd 9·5), 97·8 (sd 6·2) and 84·9 (sd 10·9), respectively. Our results showed clearly that dietary inulin intake decreased faecal Dy recovery in all four rat groups, and faecal Dy recovery was significantly higher in the old rats (10 and 20 months) than in the young and adult rats. These results show that the faecal recovery (or intestinal absorption) of Dy may vary greatly with nutritional or physiological states such as inulin intake or age. The use of rare earth elements as a faecal marker should be thus validated under each nutritional or physiological state before being employed in mineral absorption studies.
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Affiliation(s)
- Charles Coudray
- Centre de Recherche en Nutrition Humaine d'Auvergne, Unité Maladies Métaboliques et Micro-nutriments, INRA, Theix, 63122 St Genès Champanelle, France.
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Coudray C, Feillet-Coudray C, Rambeau M, Tressol JC, Gueux E, Mazur A, Rayssiguier Y. The effect of aging on intestinal absorption and status of calcium, magnesium, zinc, and copper in rats: a stable isotope study. J Trace Elem Med Biol 2006; 20:73-81. [PMID: 16785046 DOI: 10.1016/j.jtemb.2005.10.007] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2005] [Accepted: 10/21/2005] [Indexed: 11/23/2022]
Abstract
Many investigators have reported changes in mineral status with age but conflicting observations were done concerning mineral absorption. This study was conducted to clarify the effect of aging on intestinal absorption and status of minerals, using a stable isotope approach. To do so, 40 rats of different ages: 9, 22, 44, and 88 weeks were fed with a semi-purified diet for a total of 30 days. At the beginning of the 4th week, the rats received a stable isotope solution containing (44)Ca, (25)Mg, (67)Zn, and (65)Cu. Individual feces and urine were then collected during 4 consecutive days in order to measure stable isotopes by inductively coupled plasma/mass spectrometry (ICP/MS) and blood and tissues were sampled for mineral status determination. Intestinal absorption of (44)Ca and (67)Zn considerably decreased with age, whereas intestinal (25)Mg absorption decreased only moderately and intestinal (65)Cu absorption was unaffected. Plasma and bone calcium (Ca) were not modified with age whereas urinary Ca excretion considerably increased. Plasma and erythrocyte magnesium (Mg) levels were unaffected with age whereas urinary Mg excretion and Mg bone level decreased. Plasma zinc (Zn) level decreased and bone Zn level increased with age whereas red blood cell and liver Zn level and urinary Zn excretion remained unchanged. Plasma Cu level increased with age whereas liver and bone Cu levels and urinary Cu excretion remained unchanged. These results show that the effect of aging on the intestinal mineral absorption and status differ largely according to the mineral considered. Further studies are required under different nutritional conditions to explore the underlying mechanisms during aging and to adjust a better nutrition of the elderly.
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Affiliation(s)
- Charles Coudray
- Centre de Recherche en Nutrition Humaine d'Auvergne, Unité Maladies Métaboliques et Micro-nutriments, INRA, Theix, 63122 St Genès Champanelle, France.
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Meunier N, Feillet-Coudray C, Rambeau M, Andriollo-Sanchez M, Brandolini-Bunlon M, Coulter SJ, Cashman KD, Mazur A, Coudray C. Impact of micronutrient dietary intake and status on intestinal zinc absorption in late middle-aged men: the ZENITH study. Eur J Clin Nutr 2005; 59 Suppl 2:S48-52. [PMID: 16254581 DOI: 10.1038/sj.ejcn.1602298] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Adjustments in intestinal absorption and losses of zinc (Zn) are thought to maintain Zn homeostasis when dietary intake levels are altered. Zn status may also influence efficiency of intestinal Zn absorption. OBJECTIVES To determine the impact of dietary intake and status of some micronutrients on Zn absorption in late middle-aged men. DESIGN AND PARTICIPANTS Dietary intake and status of Zn, Cu, Fe, vitamin A, C and fibre, and absorption of Zn were measured in 48 men, aged 58-68 y, confined to a metabolic unit and consuming a typical French diet. Dietary intake was estimated using 4-day food-intake records (including the weekend) and the GENI program. To assess Zn status, serum, erythrocyte, urine Zn levels and serum alkaline phosphatase activity were determined. Zn absorption was determined using the isotope double-labelling method. Zn stable isotopic ratios were measured in plasma samples collected before and 48 h after isotope administration using ICP/MS. RESULTS Zn intake within the group of men varied from 5.7 to 20.5 mg/day and averaged 12.9 mg/day. Serum Zn level varied from 10 to 18 micromol/l and averaged 12.9 micromol/l. Zn absorption varied from 12 to 46% and averaged 29.7%. Zn absorption was not significantly (P > 0.05) correlated with Zn intake or with any of the Zn status parameters. Zn absorption was only slightly negatively correlated with serum and erythrocyte Zn levels and with serum Fe and ferritin levels in this study. CONCLUSION Zn dietary intake and Zn absorption were satisfactory and led to an adequate Zn status in this population.
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Affiliation(s)
- N Meunier
- Centre de Recherche en Nutrition Humaine d'Auvergne, Unité Maladies Métaboliques et Micro-nutriments, I.N.R.A., Theix, St Genès Champanelle, France
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Johansson L, Gafvelin G, Arnér ESJ. Selenocysteine in proteins-properties and biotechnological use. Biochim Biophys Acta Gen Subj 2005; 1726:1-13. [PMID: 15967579 DOI: 10.1016/j.bbagen.2005.05.010] [Citation(s) in RCA: 223] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2005] [Revised: 05/04/2005] [Accepted: 05/07/2005] [Indexed: 01/11/2023]
Abstract
Selenocysteine (Sec), the 21st amino acid, exists naturally in all kingdoms of life as the defining entity of selenoproteins. Sec is a cysteine (Cys) residue analogue with a selenium-containing selenol group in place of the sulfur-containing thiol group in Cys. The selenium atom gives Sec quite different properties from Cys. The most obvious difference is the lower pK(a) of Sec, and Sec is also a stronger nucleophile than Cys. Proteins naturally containing Sec are often enzymes, employing the reactivity of the Sec residue during the catalytic cycle and therefore Sec is normally essential for their catalytic efficiencies. Other unique features of Sec, not shared by any of the other 20 common amino acids, derive from the atomic weight and chemical properties of selenium and the particular occurrence and properties of its stable and radioactive isotopes. Sec is, moreover, incorporated into proteins by an expansion of the genetic code as the translation of selenoproteins involves the decoding of a UGA codon, otherwise being a termination codon. In this review, we will describe the different unique properties of Sec and we will discuss the prerequisites for selenoprotein production as well as the possible use of Sec introduction into proteins for biotechnological applications. These include residue-specific radiolabeling with gamma or positron emitters, the use of Sec as a reactive handle for electophilic probes introducing fluorescence or other peptide conjugates, as the basis for affinity purification of recombinant proteins, the trapping of folding intermediates, improved phasing in X-ray crystallography, introduction of 77Se for NMR spectroscopy, or, finally, the analysis or tailoring of enzymatic reactions involving thiol or oxidoreductase (redox) selenolate chemistry.
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Affiliation(s)
- Linda Johansson
- Medical Nobel Institute for Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institute, SE-171 77 Stockholm, Sweden
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Van Dael P, Lewis J, Barclay D. Stable isotope-enriched selenite and selenate tracers for human metabolic studies: a fast and accurate method for their preparation from elemental selenium and their identification and quantification using hydride generation atomic absorption spectrometry. J Trace Elem Med Biol 2004; 18:75-80. [PMID: 15487767 DOI: 10.1016/j.jtemb.2004.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Stable isotope tracers are safe and nutritionally relevant tools for the investigation of mineral metabolism in man. Increased research into the functional role of selenium has resulted in a need for well-characterised, isotopically enriched solutions of the element in order to determine the nutritional relevance of selenium fortification of foods. A simple method for the conversion of isotopically enriched elemental selenium (2.5-10 mg) into selenite and selenate, and their accurate characterisation and quantification is described. Analysis of selenite and selenate tracers using continuous-flow hydride generation-atomic absorption spectrometry technique was based on the specificity of the selenium hydride reaction and allowed their precise (RSD<2.5%) and accurate determination in aqueous solutions. The detection and determination limits were at 0.13 and 0.36 microg Se/l, respectively. Isotopically enriched elemental selenium was converted into selenite and selenate by a nitric acid and a combined nitric acid/hydrogen peroxide oxidation, respectively. The conversion was quantitative (>95%) and specific for both inorganic selenocompounds. Selenite and selenate labels were stable in 0.1 mol/l nitric acid for at least 18 months, i.e. making them ideally suitable for use in long-term metabolic studies. An overview of data relating to the absorption and retention of selenium by humans obtained using the two, well-characterised, tracers is presented and indicates that selenite and selenate are equally well retained in adult men and infants, despite differences in their absorption and urinary excretion characteristics.
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Affiliation(s)
- Peter Van Dael
- Nestlé Research Centre (PVD, DB), P.O. Box 44, Vers-chez-les-Blanc, CH-1000 Lausanne, Switzerland.
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