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Evans JR, Lawrenson JG. Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration. Cochrane Database Syst Rev 2017; 7:CD000253. [PMID: 28756617 PMCID: PMC6483250 DOI: 10.1002/14651858.cd000253.pub4] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND There is inconclusive evidence from observational studies to suggest that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C, and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration (AMD). OBJECTIVES To determine whether or not taking antioxidant vitamin or mineral supplements, or both, prevent the development of AMD. SEARCH METHODS We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2017, Issue 2), MEDLINE Ovid (1946 to 29 March 2017), Embase Ovid (1947 to 29 March 2017), AMED (Allied and Complementary Medicine Database) (1985 to 29 March 2017), OpenGrey (System for Information on Grey Literature in Europe) (www.opengrey.eu/); searched 29 March 2017, the ISRCTN registry (www.isrctn.com/editAdvancedSearch); searched 29 March 2017, ClinicalTrials.gov (www.clinicaltrials.gov); searched 29 March 2017 and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en); searched 29 March 2017. We did not use any date or language restrictions in the electronic searches for trials. SELECTION CRITERIA We included all randomised controlled trials (RCTs) comparing an antioxidant vitamin or mineral supplement (alone or in combination) to control. DATA COLLECTION AND ANALYSIS Both review authors independently assessed risk of bias in the included studies and extracted data. One author entered data into RevMan 5; the other author checked the data entry. We pooled data using a fixed-effect model. We graded the certainty of the evidence using GRADE. MAIN RESULTS We included a total of five RCTs in this review with data available for 76,756 people. The trials were conducted in Australia, Finland, and the USA, and investigated vitamin C, vitamin E, beta-carotene, and multivitamin supplements. All trials were judged to be at low risk of bias.Four studies reported the comparison of vitamin E with placebo. Average treatment and follow-up duration ranged from 4 to 10 years. Data were available for a total of 55,614 participants. There was evidence that vitamin E supplements do not prevent the development of any AMD (risk ratio (RR) 0.97, 95% confidence interval (CI) 0.90 to 1.06; high-certainty evidence), and may slightly increase the risk of late AMD (RR 1.22, 95% CI 0.89 to 1.67; moderate-certainty evidence) compared with placebo. Only one study (941 participants) reported data separately for neovascular AMD and geographic atrophy. There were 10 cases of neovascular AMD (RR 3.62, 95% CI 0.77 to 16.95; very low-certainty evidence), and four cases of geographic atrophy (RR 2.71, 95% CI 0.28 to 26.0; very low-certainty evidence). Two trials reported similar numbers of adverse events in the vitamin E and placebo groups. Another trial reported excess of haemorrhagic strokes in the vitamin E group (39 versus 23 events, hazard ratio 1.74, 95% CI 1.04 to 2.91, low-certainty evidence).Two studies reported the comparison of beta-carotene with placebo. These studies took place in Finland and the USA. Both trials enrolled men only. Average treatment and follow-up duration was 6 years and 12 years. Data were available for a total of 22,083 participants. There was evidence that beta-carotene supplements did not prevent any AMD (RR 1.00, 95% CI 0.88 to 1.14; high-certainty evidence) nor have an important effect on late AMD (RR 0.90, 95% CI 0.65 to 1.24; moderate-certainty evidence). Only one study (941 participants) reported data separately for neovascular AMD and geographic atrophy. There were 10 cases of neovascular AMD (RR 0.61, 95% CI 0.17 to 2.15; very low-certainty evidence) and 4 cases of geographic atrophy (RR 0.31 95% CI 0.03 to 2.93; very low-certainty evidence). Beta-carotene was associated with increased risk of lung cancer in people who smoked.One study reported the comparison of vitamin C with placebo, and multivitamin (Centrum Silver) versus placebo. This was a study in men in the USA with average treatment duration and follow-up of 8 years for vitamin C and 11 years for multivitamin. Data were available for a total of 14,236 participants. AMD was assessed by self-report followed by medical record review. There was evidence that vitamin C supplementation did not prevent any AMD (RR 0.96, 95% CI 0.79 to 1.18; high-certainty evidence) or late AMD (RR 0.94, 0.61 to 1.46; moderate-certainty evidence). There was a slight increased risk of any AMD (RR 1.21, 95% CI 1.02 to 1.43; moderate-certainty evidence) and late AMD (RR 1.22, 95% CI 0.88 to 1.69; moderate-certainty evidence) in the multivitamin group. Neovascular AMD and geographic atrophy were not reported separately. Adverse effects were not reported but there was possible increased risk of skin rashes in the multivitamin group.Adverse effects were not consistently reported in these eye studies, but there is evidence from other large studies that beta-carotene increases the risk of lung cancer in people who smoke or who have been exposed to asbestos.None of the studies reported quality of life or resource use and costs. AUTHORS' CONCLUSIONS Taking vitamin E or beta-carotene supplements will not prevent or delay the onset of AMD. The same probably applies to vitamin C and the multivitamin (Centrum Silver) investigated in the one trial reported to date. There is no evidence with respect to other antioxidant supplements, such as lutein and zeaxanthin. Although generally regarded as safe, vitamin supplements may have harmful effects, and clear evidence of benefit is needed before they can be recommended. People with AMD should see the related Cochrane Review on antioxidant vitamin and mineral supplements for slowing the progression of AMD, written by the same review team.
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Affiliation(s)
- Jennifer R Evans
- London School of Hygiene & Tropical MedicineCochrane Eyes and Vision, ICEHKeppel StreetLondonUKWC1E 7HT
| | - John G Lawrenson
- City University of LondonCentre for Applied Vision Research, School of Health SciencesNorthampton SquareLondonUKEC1V 0HB
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Effect of infrared light on live blood cells: Role of β-carotene. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017; 171:104-116. [DOI: 10.1016/j.jphotobiol.2017.04.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 04/27/2017] [Indexed: 01/14/2023]
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Lutein and atherosclerosis: Belfast versus Toulouse revisited. Med Hypotheses 2017; 98:63-68. [DOI: 10.1016/j.mehy.2016.10.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 10/20/2016] [Accepted: 10/26/2016] [Indexed: 11/21/2022]
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Riccioni G, D'Orazio N, Menna V, De Lorenzo A. Fat Soluble Vitamins and Immune System: An Overview. EUR J INFLAMM 2016. [DOI: 10.1177/1721727x0300100202] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The immune system guards against invasion by foreign microrganisms and molecules. In this way, it protects from fatal illnesses and communicable diseases. Its proper functioning is fundamental for survival. Research has demonstrated that proper nutrition plays a crucial role in the prevention of chronic disease. Protein-energy malnutrition is associated with a significant impairment of cell-mediated immunity, phagocyte function, the complement system, secretory immunoglobulin A antibody concentrations, and cytokine production. Deficiency of single nutrients also results in altered immune responses; this is observed even when the deficiency state is relatively mild. Of the micronutrients, zinc, selenium, iron, copper, vitamins A,C,E and B, and folic acid have important influences on the immune response. It is now apparent that vitamin E and β-carotene have more subtle roles and that deficient dietary intake of these vitamins increases susceptibility to certain cancers and cardiovascular disease. This reflects, in part, the antioxidant properties of the vitamins and their ability to reduce free radical-mediated damage to DNA, proteins and lipid membranes. These findings have considerable practical and public health significance. The aim of this review is to give an up-to date account of the roles of selected fat-soluble vitamins in health and disease.
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Affiliation(s)
| | | | | | - A. De Lorenzo
- Human Nutrition, University “Tor Vergata”, Rome, Italy
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Silge A, Abdou E, Schneider K, Meisel S, Bocklitz T, Lu-Walther HW, Heintzmann R, Rösch P, Popp J. Shedding light on host niches: label-freein situdetection ofMycobacterium gordonaevia carotenoids in macrophages by Raman microspectroscopy. Cell Microbiol 2015; 17:832-42. [DOI: 10.1111/cmi.12404] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 12/01/2014] [Accepted: 12/03/2014] [Indexed: 01/03/2023]
Affiliation(s)
- Anja Silge
- Institute of Physical Chemistry and Abbe Center of Photonics; Friedrich-Schiller-University Jena; Helmholtzweg 4 Jena D-07743 Germany
- InfectoGnostics Research Campus Jena; Center for Applied Research; Philosophenweg 7 Jena D-07743 Germany
| | - Elias Abdou
- Institute of Physical Chemistry and Abbe Center of Photonics; Friedrich-Schiller-University Jena; Helmholtzweg 4 Jena D-07743 Germany
- InfectoGnostics Research Campus Jena; Center for Applied Research; Philosophenweg 7 Jena D-07743 Germany
- Center for Sepsis Control and Care; University Hospital Jena; Erlanger Alee 101 Jena D-07747 Germany
| | - Kilian Schneider
- Institute of Physical Chemistry and Abbe Center of Photonics; Friedrich-Schiller-University Jena; Helmholtzweg 4 Jena D-07743 Germany
- InfectoGnostics Research Campus Jena; Center for Applied Research; Philosophenweg 7 Jena D-07743 Germany
| | - Susann Meisel
- Institute of Physical Chemistry and Abbe Center of Photonics; Friedrich-Schiller-University Jena; Helmholtzweg 4 Jena D-07743 Germany
- InfectoGnostics Research Campus Jena; Center for Applied Research; Philosophenweg 7 Jena D-07743 Germany
| | - Thomas Bocklitz
- Institute of Physical Chemistry and Abbe Center of Photonics; Friedrich-Schiller-University Jena; Helmholtzweg 4 Jena D-07743 Germany
- InfectoGnostics Research Campus Jena; Center for Applied Research; Philosophenweg 7 Jena D-07743 Germany
| | - Hui-Wen Lu-Walther
- Leibniz Institute of Photonic Technology; Albert-Einstein-Strasse 9 Jena D-07745 Germany
| | - Rainer Heintzmann
- Institute of Physical Chemistry and Abbe Center of Photonics; Friedrich-Schiller-University Jena; Helmholtzweg 4 Jena D-07743 Germany
- Leibniz Institute of Photonic Technology; Albert-Einstein-Strasse 9 Jena D-07745 Germany
- Randall Division of Cell and Molecular Biophysics; King's College London; London SE1 1UL UK
| | - Petra Rösch
- Institute of Physical Chemistry and Abbe Center of Photonics; Friedrich-Schiller-University Jena; Helmholtzweg 4 Jena D-07743 Germany
- InfectoGnostics Research Campus Jena; Center for Applied Research; Philosophenweg 7 Jena D-07743 Germany
| | - Jürgen Popp
- Institute of Physical Chemistry and Abbe Center of Photonics; Friedrich-Schiller-University Jena; Helmholtzweg 4 Jena D-07743 Germany
- InfectoGnostics Research Campus Jena; Center for Applied Research; Philosophenweg 7 Jena D-07743 Germany
- Leibniz Institute of Photonic Technology; Albert-Einstein-Strasse 9 Jena D-07745 Germany
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Hendrickson SJ, Hazra A, Chen C, Eliassen AH, Kraft P, Rosner BA, Willett WC. β-Carotene 15,15'-monooxygenase 1 single nucleotide polymorphisms in relation to plasma carotenoid and retinol concentrations in women of European descent. Am J Clin Nutr 2012; 96:1379-89. [PMID: 23134893 PMCID: PMC3497927 DOI: 10.3945/ajcn.112.034934] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Carotenoids have been hypothesized to reduce the risk of many diseases, but associations with intakes or blood concentrations may arise from other constituents of fruit and vegetables. Use of genetic variation in β-carotene 15,15'-monooxygenase 1 (BCMO1), a key enzyme in provitamin A carotenoid metabolism, as a surrogate for carotenoid exposure may aid in determining the role of carotenoids unconfounded by other carotenoid-containing food constituents, but important variants must be identified. OBJECTIVE Our goal was to select BCMO1 single nucleotide polymorphisms (SNPs) that predict plasma carotenoid concentrations for use in future epidemiologic studies. DESIGN We assessed the associations between 224 SNPs in BCMO1 ± 20 kb imputed from the 1000 Genomes Project EUR reference panel with plasma carotenoid and retinol concentrations by using 7 case-control data sets (n = 2344) within the Nurses' Health Study, randomly divided into training (n = 1563) and testing (n = 781) data sets. SNPs were chosen in the training data set through stepwise selection in multivariate linear regression models; β-coefficients were used as weights in weighted gene scores. RESULTS Two or 3 SNPs were selected as predictors of β-carotene, α-carotene, β-cryptoxanthin, and lutein/zeaxanthin. In the testing data set, the weighted gene scores were significantly associated with plasma concentrations of the corresponding carotenoid (P = 6.4 × 10⁻¹², 3.3 × 10⁻³, 0.02, and 1.8 × 10⁻¹⁷, respectively), and concentrations differed by 48%, 15%, 15%, and 36%, respectively, across extreme score quintiles. CONCLUSIONS SNPs in BCMO1 are associated with plasma carotenoid concentrations. Given adequate sample size, the gene scores may be useful surrogates for carotenoid exposure in future studies.
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Affiliation(s)
- Sara J Hendrickson
- Department of Epidemiology, Harvard School of Public Health, Boston, MA, USA
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Evans JR, Lawrenson JG. Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration. Cochrane Database Syst Rev 2012:CD000253. [PMID: 22696317 DOI: 10.1002/14651858.cd000253.pub3] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
BACKGROUND There is inconclusive evidence from observational studies to suggest that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration (AMD). OBJECTIVES To examine the evidence as to whether or not taking antioxidant vitamin or mineral supplements prevents the development of AMD. SEARCH METHODS We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2011, Issue 12), MEDLINE (January 1950 to January 2012), EMBASE (January 1980 to January 2012), Open Grey (System for Information on Grey Literature in Europe) (www.opengrey.eu/), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). There were no date or language restrictions in the electronic searches for trials. The electronic databases were last searched on 26 January 2012. SELECTION CRITERIA We included all randomised controlled trials (RCTs) comparing an antioxidant vitamin and/or mineral supplement (alone or in combination) to control. DATA COLLECTION AND ANALYSIS Both review authors independently assessed risk of bias in the included studies and extracted data. One author entered data into RevMan 5 and the other author checked the data entry. We pooled data using a fixed-effect model. MAIN RESULTS We included four RCTs in this review; 62,520 people were included in the analyses. The trials were conducted in Australia, Finland and the USA and investigated vitamin E and beta-carotene supplements. Overall the quality of the evidence was high. People who took these supplements were not at decreased (or increased) risk of developing AMD. The pooled risk ratio for any antioxidant supplement in the prevention of any AMD was 0.98 (95% confidence interval 0.89 to 1.08) and for advanced AMD was 1.05 (95% CI 0.80 to 1.39). Similar results were seen when the analyses were restricted to beta-carotene and alpha-tocopherol alone. AUTHORS' CONCLUSIONS There is accumulating evidence that taking vitamin E or beta-carotene supplements will not prevent or delay the onset of AMD. There is no evidence with respect to other antioxidant supplements, such as vitamin C, lutein and zeaxanthin, or any of the commonly marketed multivitamin combinations. Although generally regarded as safe, vitamin supplements may have harmful effects and clear evidence of benefit is needed before they can be recommended. People with AMD should see the related Cochrane review 'Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration' written by the same review team.
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Affiliation(s)
- Jennifer R Evans
- Cochrane Eyes and Vision Group, ICEH, London School of Hygiene & Tropical Medicine, London, UK.
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Di Tomo P, Canali R, Ciavardelli D, Di Silvestre S, De Marco A, Giardinelli A, Pipino C, Di Pietro N, Virgili F, Pandolfi A. β-Carotene and lycopene affect endothelial response to TNF-α reducing nitro-oxidative stress and interaction with monocytes. Mol Nutr Food Res 2011; 56:217-27. [PMID: 22162208 DOI: 10.1002/mnfr.201100500] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 09/06/2011] [Accepted: 09/26/2011] [Indexed: 11/12/2022]
Abstract
SCOPE Cardiovascular disease (CVD) is associated with vascular oxidative imbalance and inflammation. Increased reactive oxygen species (ROS) generation is associated with a functional inactivation of nitric oxide (NO) due to the reaction with O₂⁻, leading to peroxynitrite (ONOO⁻) formation and subsequent reduction in the beneficial effect of vascular NO bioavailability. Carotenoids'-rich diets have been associated with decreased risk of CVD, but the underlying mechanism is still unknown. METHODS AND RESULTS In human umbilical vein endothelial cells (HUVECs), both β-carotene (BC) or lycopene (Lyc) significantly affected tumor necrosis factor-α (TNF-α)-induced inflammation, being associated with a significant decrease in the generation of ROS (spectrofluorometry) and nitrotyrosine (an index of ONOO⁻ formation, cytofluorimetry), an increased NO/cGMP (cyclic guanosine monophosphate) levels (EIA), and a down-regulation of NF-κB-dependent adhesion molecule expression (Western blot and EMSA) and monocyte-HUVEC interaction (adhesion assay). Our results indicate that BC or Lyc treatment reduce the inflammatory response in TNF-α-treated HUVECs. This is due to the redox balance protection and to the maintenance of NO bioavailability. CONCLUSION Our observations provide background for a novel mechanism for carotenoids' anti-inflammatory activity in the vasculature and may contribute to a better understanding of the protective effects of carotenoid-rich diets against CVD risk.
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Affiliation(s)
- Pamela Di Tomo
- Department of Biomedical Sciences, "G. d'Annunzio" University, Chieti-Pescara, Italy
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Immunomodulatory Effects of Saffron: A Randomized Double-Blind Placebo-Controlled Clinical Trial. Phytother Res 2011; 25:1801-5. [DOI: 10.1002/ptr.3484] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Revised: 02/28/2011] [Accepted: 03/01/2011] [Indexed: 12/17/2022]
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Abstract
Phospholipid hydroperoxides (PLOOH) accumulate abnormally in the erythrocytes of dementia patients, and dietary xanthophylls (polar carotenoids such as astaxanthin) are hypothesised to prevent the accumulation. In the present study, we conducted a randomised, double-blind, placebo-controlled human trial to assess the efficacy of 12-week astaxanthin supplementation (6 or 12 mg/d) on both astaxanthin and PLOOH levels in the erythrocytes of thirty middle-aged and senior subjects. After 12 weeks of treatment, erythrocyte astaxanthin concentrations were higher in both the 6 and 12 mg astaxanthin groups than in the placebo group. In contrast, erythrocyte PLOOH concentrations were lower in the astaxanthin groups than in the placebo group. In the plasma, somewhat lower PLOOH levels were found after astaxanthin treatment. These results suggest that astaxanthin supplementation results in improved erythrocyte antioxidant status and decreased PLOOH levels, which may contribute to the prevention of dementia.
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Antioxidant effect of lutein towards phospholipid hydroperoxidation in human erythrocytes. Br J Nutr 2009; 102:1280-4. [DOI: 10.1017/s0007114509990316] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Peroxidised phospholipid-mediated cytotoxity is involved in the pathophysiology of many diseases; for example, phospholipid hydroperoxides (PLOOH) are abnormally increased in erythrocytes of dementia patients. Dietary carotenoids (especially xanthophylls, polar carotenoids such as lutein) have gained attention as potent inhibitors against erythrocyte phospholipid hydroperoxidation, thereby making them plausible candidates for preventing diseases (i.e. dementia). To evaluate these points, we investigated whether orally administered lutein is distributed to human erythrocytes, and inhibits erythrocyte PLOOH formation. Six healthy subjects took one capsule of food-grade lutein (9·67 mg lutein per capsule) once per d for 4 weeks. Before and during the supplementation period, carotenoids and PLOOH in erythrocytes and plasma were determined by our developed HPLC technique. The administered lutein was incorporated into human erythrocytes, and erythrocyte PLOOH level decreased after the ingestion for 2 and 4 weeks. The antioxidative effect of lutein was confirmed on erythrocyte membranes, but not in plasma. These results suggest that lutein has the potential to act as an important antioxidant molecule in erythrocytes, and it thereby may contribute to the prevention of dementia. Therefore future biological and clinical studies will be required to evaluate the efficacy as well as safety of lutein in models of dementia with a realistic prospect of its use in human therapy.
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Christen W, Glynn R, Sperduto R, Chew E, Buring J. Age-related cataract in a randomized trial of beta-carotene in women. Ophthalmic Epidemiol 2009; 11:401-12. [PMID: 15590586 DOI: 10.1080/09286580490515152] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE To examine the development of age-related cataract in a trial of beta-carotene supplementation in women. METHODS The Women's Health Study is a randomized, double-masked, placebo-controlled trial originally designed to test the balance of benefits and risks of beta-carotene (50 mg on alternate days), vitamin E, and aspirin in the primary prevention of cancer and cardiovascular disease among 39,876 female health professionals aged 45 years or older. The beta-carotene component of the trial was terminated early after a median treatment duration of 2.1 years. Main outcome measures were visually-significant cataract and cataract extraction, based on self-report confirmed by medical record review. RESULTS There were 129 cataracts in the beta-carotene group and 133 in the placebo group (relative risk [RR] = 0.95, 95% CI 0.75-1.21). For cataract extraction, there were 94 cases in the beta-carotene group and 89 cases in the placebo group (RR = 1.04, 95% CI 0.78-1.39). Subgroup analyses suggested a possible beneficial effect of beta-carotene in smokers. CONCLUSIONS These randomized trial data from a large population of apparently healthy female health professionals indicate that two years of beta-carotene treatment has no large beneficial or harmful effect on the development of cataract during the treatment period.
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Affiliation(s)
- William Christen
- Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA.
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Porrini M, Riso P. Factors influencing the bioavailability of antioxidants in foods: a critical appraisal. Nutr Metab Cardiovasc Dis 2008; 18:647-650. [PMID: 18996686 DOI: 10.1016/j.numecd.2008.08.004] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2008] [Accepted: 08/13/2008] [Indexed: 12/31/2022]
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Bioavailability and nutritional effects of carotenoids from organically and conventionally produced carrots in healthy men. Br J Nutr 2008; 101:1664-72. [DOI: 10.1017/s0007114508116269] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
It has been hypothesised that organically grown vegetables are healthier than conventionally produced ones due to a higher content of phytochemicals. However, few data from controlled human studies exist. The aim of the present study was to compare the carotenoid content and antioxidant capacity of organically and conventionally produced carrots under defined conditions. Furthermore, a human intervention study was conducted to compare bioavailability, plasma antioxidant capacity, endogenous DNA strand breaks and immune parameters in healthy men ingesting carrots from different agricultural systems. Thirty-six volunteers consumed either organically or conventionally produced blanched carrots (200 g/d; 2 weeks) or no carrots in a double-blind, randomised intervention study. No statistically significant differences were observed in the total carotenoid contents (121 (sd7) μg/g organicv.116 (sd13) μg/g conventional) and the antioxidant capacities (0·43 (sd0·08) μmol Trolox equivalents/g organicv.0·32 (sd0·07) μmol Trolox equivalents/g conventional) of the carrots administered to the volunteers. Intake of organically or conventionally produced carrots significantly increased (P < 0·001) plasma α- and β-carotene concentrations in both intervention groups without differences in plasma carotenoid concentrations. Consumption of carrots did not lead to significant changes in the plasma antioxidant status, endogenous DNA strand breaks and parameters of the immune system in all groups. Therefore, these results indicate that the agricultural system has neither an effect on the carotenoid content, the antioxidant capacity of carrots, nor on the bioavailability of carotenoids and on antioxidant, antigenotoxic and immunological effects as assessed in a human intervention study.
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Nakagawa K, Kiko T, Hatade K, Asai A, Kimura F, Sookwong P, Tsuduki T, Arai H, Miyazawa T. Development of a high-performance liquid chromatography-based assay for carotenoids in human red blood cells: Application to clinical studies. Anal Biochem 2008; 381:129-34. [DOI: 10.1016/j.ab.2008.06.038] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 06/27/2008] [Accepted: 06/27/2008] [Indexed: 11/27/2022]
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Evans JR, Henshaw K. Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration. Cochrane Database Syst Rev 2008:CD000253. [PMID: 18253971 DOI: 10.1002/14651858.cd000253.pub2] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Some observational studies have suggested that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration (AMD). OBJECTIVES The aim of this review was to examine the evidence as to whether or not taking vitamin or mineral supplements prevents the development of AMD. SEARCH STRATEGY We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) in The Cochrane Library (2007, Issue 3), MEDLINE (1966 to August 2007), SIGLE (1980 to 2005/03), EMBASE (1980 to August 2007), National Research Register (2007, Issue 3), AMED (1985 to January 2006) and PubMed (on 24 January 2006 covering last 60 days), reference lists of identified reports and the Science Citation Index. We contacted investigators and experts in the field for details of unpublished studies. SELECTION CRITERIA We included all randomised trials comparing an antioxidant vitamin and/or mineral supplement (alone or in combination) to control. We included only studies where supplementation had been given for at least one year. DATA COLLECTION AND ANALYSIS Both review authors independently extracted data and assessed trial quality. Data were pooled using a fixed-effect model. MAIN RESULTS Three randomised controlled trials were included in this review (23,099 people randomised). These trials investigated alpha-tocopherol and beta-carotene supplements. There was no evidence that antioxidant vitamin supplementation prevented or delayed the onset of AMD. The pooled risk ratio for any age-related maculopathy (ARM) was 1.04 (95% CI 0.92 to 1.18), for AMD (late ARM) was 1.03 (95% CI 0.74 to 1.43). Similar results were seen when the analyses were restricted to beta-carotene and alpha-tocopherol. AUTHORS' CONCLUSIONS There is no evidence to date that the general population should take antioxidant vitamin and mineral supplements to prevent or delay the onset of AMD. There are several large ongoing trials. People with AMD should see the related Cochrane review "Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration" written by the same author.
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Affiliation(s)
- J R Evans
- London School of Hygiene & Tropical Medicine, International Centre for Eye Health, Keppel Street, London, UK WC1E 7HT.
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Christen WG, Manson JE, Glynn RJ, Gaziano JM, Chew EY, Buring JE, Hennekens CH. Beta carotene supplementation and age-related maculopathy in a randomized trial of US physicians. ACTA ACUST UNITED AC 2007; 125:333-9. [PMID: 17353403 PMCID: PMC1821351 DOI: 10.1001/archopht.125.3.333] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE To test whether beta carotene supplementation affects the incidence of age-related maculopathy (ARM) in a large-scale randomized trial. DESIGN Randomized, double-masked, placebo-controlled trial among 22 071 apparently healthy US male physicians aged 40 to 84 years. Participants were randomly assigned to receive beta carotene (50 mg every other day) or placebo. Main Outcome Measure Incident ARM responsible for a reduction in best-corrected visual acuity to 20/30 or worse. RESULTS After 12 years of treatment and follow-up, there were 162 cases of ARM in the beta carotene group vs 170 cases in the placebo group (relative risk [RR], 0.96; 95% confidence interval [CI], 0.78-1.20). The results were similar for the secondary end points of ARM with or without vision loss (275 vs 274 cases; RR, 1.01; 95% CI, 0.86-1.20) and advanced ARM (63 vs 66 cases; RR, 0.97; 95% CI, 0.69-1.37). CONCLUSIONS These randomized data relative to 12 years of treatment among a large population of apparently healthy men indicate that beta carotene supplementation has no beneficial or harmful effect on the incidence of ARM. Long-term supplemental use of beta carotene neither decreases nor increases the risk of ARM.
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Affiliation(s)
- William G Christen
- Division of Preventive Medicine, Department of Medicine, Brigham and Women's Hospital, 900 Commonwealth Ave E, Boston, MA 02215-1204, USA.
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20
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Vitaglione P, Fogliano V, Stingo S, Scalfi L, Caporaso N, Morisco F. Development of a tomato-based food for special medical purposes as therapy adjuvant for patients with HCV infection. Eur J Clin Nutr 2006; 61:906-15. [PMID: 17180159 DOI: 10.1038/sj.ejcn.1602571] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
OBJECTIVE The present study aimed to develop a food for special medical purposes (FSMP) and to assess its efficacy as adjuvant therapy in patients with chronic hepatitis C virus (HCV). DESIGN Open randomized clinical trials with a tomato-based FSMP used as adjuvant treatment to the pharmacological therapy with pegilated interferon and ribavirin. SUBJECTS Eight healthy volunteers and 39 HCV patients. INTERVENTIONS For the bioavailability study, healthy subjects consumed 100 g/die FSMP for a week and their serum carotenoid profile at baseline, after the week of administration and 7 days later was determined. The same quantity of FSMP for 6 months by 20 of the 39 HCV patients was consumed in the clinical trial. Serum transaminase, haemoglobin (Hb) and hydroperoxide concentrations during the therapy were monitored in all patients. RESULTS FSMP consumption caused a fourfold increase of lycopene serum concentration in healthy subjects. A significant increase of carotenoids after 1 month of consumption also in patients with HCV was recorded. Transaminase and Hb serum levels, as well as therapeutic response, were not influenced by FSMP. The decrease in serum hydroperoxides was independent from FSMP consumption in long-term responder patients, whereas nonresponder (NR) patients of FSMP group showed higher reductions than NR patients of Control group. CONCLUSIONS The FSMP was effective in improving carotenoid status in healthy subjects. In HCV patients, it did not influence the therapeutic response, but it prevented carotenoid serum depletion and it was effective in improving the oxidative status during antiviral therapy in NR patients.
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Affiliation(s)
- P Vitaglione
- Department of Food Science, University of Naples Federico II, Parco Gussone, Portici (NA), Italy
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21
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Franssen-van Hal NLW, Bunschoten JE, Venema DP, Hollman PCH, Riss G, Keijer J. Human intestinal and lung cell lines exposed to β-carotene show a large variation in intracellular levels of β-carotene and its metabolites. Arch Biochem Biophys 2005; 439:32-41. [PMID: 15950170 DOI: 10.1016/j.abb.2005.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2005] [Revised: 04/26/2005] [Accepted: 05/02/2005] [Indexed: 11/26/2022]
Abstract
Although in vitro models are often used in beta-carotene research, knowledge about the uptake and metabolism of beta-carotene in cell lines is lacking. We measured by HPLC the intracellular levels of beta-carotene and its metabolites in 9 human intestinal and lung cell lines after exposure to 1 microM beta-carotene during 2, 6, 30, 54 h, and 3 weeks. In three colorectal carcinoma cell lines only low levels of beta-carotene could be detected and an apparent linear increase in intracellular beta-carotene was observed during the whole exposure period of 3 weeks. The remaining cell lines (an SV40 transformed colon cell line, a small intestinal carcinoma cell line and several lung cell lines) had medium or high intracellular beta-carotene levels. In these cell lines intracellular beta-carotene quickly increased during the first 54 h of exposure and after 3 weeks no further increase was observed, suggesting a stable level of beta-carotene after 54 h. Estimated intracellular concentrations at steady-state levels varied between 2 and 5 microM (low) or 9 and 55 microM (medium/high). Our results seem to indicate that an active uptake mechanism of beta-carotene exists in at least a subset of cell lines. Seven different beta-carotene metabolites were detected in the various cell lines (cis-carotene, retinol, three epoxy-carotenes, and two retinyl esters). Metabolite levels were the highest in cells with medium or high beta-carotene levels. Each cell line appeared to have a distinct metabolite profile. No intestinal or lung specific pattern could be found, but two epoxy-carotene metabolites were not detectable in the colon cell lines.
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Bartlett H, Eperjesi F. Possible contraindications and adverse reactions associated with the use of ocular nutritional supplements. Ophthalmic Physiol Opt 2005; 25:179-94. [PMID: 15854063 DOI: 10.1111/j.1475-1313.2005.00294.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The role of oxidation in the development of age-related eye disease has prompted interest in the use of nutritional supplementation for prevention of onset and progression. Our aim is to highlight possible contraindications and adverse reactions of isolated or high dose ocular nutritional supplements. Web of Science and PubMed database searches were carried out, followed by a manual search of the bibliographies of retrieved articles. Vitamin A should be avoided in women who may become pregnant, in those with liver disease, and in people who drink heavily. Relationships have been found between vitamin A and reduced bone mineral density, and beta-carotene and increased risk of lung cancer in smoking males. Vitamin E and Ginkgo biloba have anticoagulant and anti-platelet effects respectively, and high doses are contraindicated in those being treated for vascular disorders. Those patients with contraindications or who are considered at risk of adverse reactions should be advised to seek specialist dietary advice via their medical practitioner.
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Affiliation(s)
- Hannah Bartlett
- Neurosciences Research Institute, Aston University, Birmingham, UK.
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23
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Keijer J, Bunschoten A, Palou A, Franssen-van Hal NLW. Beta-carotene and the application of transcriptomics in risk–benefit evaluation of natural dietary components. Biochim Biophys Acta Mol Basis Dis 2005; 1740:139-46. [PMID: 15949680 DOI: 10.1016/j.bbadis.2005.01.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 12/15/2004] [Accepted: 01/04/2005] [Indexed: 10/25/2022]
Abstract
Beta-carotene is a natural food component that is present in fruits and vegetables and is also used as a food colorant and a supplement. Beta-carotene is an anti-oxidant and a source of vitamin A. It is endowed with health beneficial properties, but a number of studies showed that with high intakes it may increase the risk for lung cancer in at risk individuals (heavy smokers, asbestos workers and alcohol users). To establish the window of benefit, it is necessary to identify early markers of effect and to obtain insight in the mechanism of action of beta-carotene, in the absence and presence of environmental risk factors. Genomics technologies are well suited to dissect the mechanisms of action and identify the markers of effect. Human cell lines can be used to analyse the effects of beta-carotene, but exposure studies with beta-carotene show that cell lines display a widely variant behaviour, which hampers translation to the in vivo situation in humans. Alternatively, animal studies can be used. Especially the ferret seems to be a good model, but little sequence information of this species is available. However, heterologous hybridization on human cDNA seems possible and provides and a new tool for molecular analysis of health effects of beta-carotene.
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Affiliation(s)
- Jaap Keijer
- RIKILT-Institute of Food Safety, Food Bioactives Group. Bornsesteeg 45, P.O. Box 230, 6700 AE, Wageningen, The Netherlands.
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Hak AE, Ma J, Powell CB, Campos H, Gaziano JM, Willett WC, Stampfer MJ. Prospective study of plasma carotenoids and tocopherols in relation to risk of ischemic stroke. Stroke 2004; 35:1584-8. [PMID: 15178820 DOI: 10.1161/01.str.0000132197.67350.bd] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND AND PURPOSE Intake of fruits and vegetables has been related to lower risk of ischemic stroke, but nutrients responsible for this apparent benefit remain ill-defined. Tocopherols (vitamin E) have also been proposed to be protective. METHODS We conducted a prospective, nested case-control analysis among male physicians without diagnosed cardiovascular disease followed-up for up to 13 years in the Physicians' Health Study. Samples from 297 physicians with ischemic stroke were analyzed with paired controls, matched for age and smoking, for 5 major carotenoids (alpha- and beta-carotene, beta-cryptoxanthin, lutein, and lycopene), retinol, and alpha- and gamma-tocopherol. RESULTS Baseline plasma levels of alpha-carotene and beta-carotene and lycopene tended to be inversely related to risk of ischemic stroke with an apparent threshold effect. As compared with men whose plasma levels were in the lowest quintile, the multivariate adjusted odds ratios (ORs) of ischemic stroke among men with levels in the second through fifth quintiles were 0.59 (95% CI, 0.36 to 0.98) for alpha-carotene, 0.62 (95% CI, 0.38 to 1.01) for beta-carotene, and 0.61 (95% CI, 0.37 to 1.00) for lycopene. A tendency toward an inverse association was found for beta-cryptoxanthin, but the result was not statistically significant. No association was found for lutein, retinol, and tocopherols. CONCLUSIONS Our data suggest that higher plasma levels of carotenoids, as markers of fruit and vegetable intake, are inversely related to risk of ischemic stroke and provide support for recommendations to consume fruits and vegetables regularly.
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Affiliation(s)
- A Elisabeth Hak
- Department of Epidemiology, Harvard School of Public Health, Boston, Mass, USA
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Abstract
BACKGROUND AND AIM Few published studies have described the bioavailability of the different carotenoids in spinach. This was designed to evaluate the effects on plasma carotenoid concentrations of a daily consumption of spinach (rich in lutein and beta-carotene), alone or together with lycopene-rich tomato puree. METHODS AND RESULTS Nine healthy young women consumed a standard low-carotenoid diet during the pre-study phase, the spinach diet (standard diet plus 150 g spinach: 9 mg lutein, 4 mg beta-carotene) from day 0 to day 21, and then, after a wash-out period, the spinach-tomato diet (standard diet plus 150 g spinach and 25 g tomato puree: 9 mg lutein, 4.3 mg beta-carotene and 7 mg lycopene) from day 35 to day 56. The spinach and spinach-tomato supplements were consumed together with 10 g olive oil. Fasting blood samples were collected on day -7, and every week thereafter. Plasma carotenoid concentrations significantly decreased during the standard low-carotenoid diet. Lutein levels gradually increased after spinach consumption from 0.36+/-0.05 to 1.59+/-0.19 micromol/L (p<0.0001), decreased during the wash-out period from 1.59+/-0.19 to 0.62+/-0.07 micromol/L (p<0.001), and rose again after the intake of spinach-tomato puree from 0.62+/-0.07 to 1.55+/-0.17 micromol/L (p<0.0001). beta-carotene levels also increased during both dietary supplementation periods. Lycopene decreased during the spinach diet from 0.20+/-0.03 to 0.07+/-0.01 micromol/L (p<0.001) and increased during the spinach-tomato diet from 0.05+/-0.01 to 0.52+/-0.06 micromol/L (p<0.0001). CONCLUSIONS The results of this study confirm that a regular intake of selected vegetables leads to a progressive increase in plasma carotenoid concentrations. The addition of tomato puree to spinach does not decrease lutein plasma concentrations. Furthermore, baseline plasma levels of lutein and lycopene are important variables affecting the relative increase in their levels after supplementation: ie more depleted subjects are expected to have a greater percent rise in plasma carotenoid concentrations.
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Affiliation(s)
- P Riso
- Department of Food Science, Technology and Microbiology, Division of Human Nutrition, University of Milan, Milan, Italy.
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Riso P, Visioli F, Erba D, Testolin G, Porrini M. Lycopene and vitamin C concentrations increase in plasma and lymphocytes after tomato intake. Effects on cellular antioxidant protection. Eur J Clin Nutr 2004; 58:1350-8. [PMID: 15054415 DOI: 10.1038/sj.ejcn.1601974] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE This study seeks to verify whether the regular consumption of small amounts of tomato products can protect lymphocyte DNA and lipids from oxidative damage. DESIGN Standardized dietary intervention. SUBJECTS Twelve healthy female subjects (mean age 25.2 y). INTERVENTION Subjects were instructed to follow a standardized diet for 1 week, followed by 3 weeks consumption of the same diet enriched with small amounts of different tomato products providing as a mean 8 mg lycopene, 0.5 mg beta-carotene and 11 mg vitamin C per day. Plasma and lymphocyte concentrations of carotenoids, vitamin C and vitamin E were analysed. Ex vivo protection of lymphocyte DNA from oxidative injury produced by iron ions was evaluated by means of the Comet assay, and lipid peroxidation by HPLC analysis of malondialdehyde (MDA). RESULTS Dietary intervention with tomato products increased lycopene concentration both in plasma (P < 0.001) and lymphocytes (P < 0.01). Vitamin C concentrations increased by approximately 35% in plasma (P < 0.05) and by approximately 230% in lymphocytes (P < 0.005). Vitamin E decreased significantly in plasma (P < 0.0001) but not in lymphocytes. Finally, there was an improved protection from DNA oxidative damage (P < 0.05) with no significant effect on MDA levels. CONCLUSIONS Our results suggest that tomato products are not only good sources of lycopene but also sources of bioavailable vitamin C. A Regular intake of small amounts of tomato products can increase cell protection from DNA damage induced by oxidant species. This effect may originate from the synergism of different antioxidants present in tomatoes.
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Affiliation(s)
- P Riso
- Department of Food Science and Technology, Division of Human Nutrition, University of Milan, Italy.
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Mozaffarieh M, Sacu S, Wedrich A. The role of the carotenoids, lutein and zeaxanthin, in protecting against age-related macular degeneration: a review based on controversial evidence. Nutr J 2003; 2:20. [PMID: 14670087 PMCID: PMC305368 DOI: 10.1186/1475-2891-2-20] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2003] [Accepted: 12/11/2003] [Indexed: 11/10/2022] Open
Abstract
PURPOSE A review of the role of the carotenoids, lutein and zeaxanthin, and their function in altering the pathogenesis of age-related macular degeneration (AMD). METHODS Medline and Embase search. RESULTS Recent evidence introduces the possibility that lutein and zeaxanthin, carotenoids found in a variety of fruits and vegetables may protect against the common eye disease of macular degeneration. This potential and the lack to slow the progression of macular degeneration, has fueled high public interest in the health benefits of these carotenoids and prompted their inclusion in various supplements. The body of evidence supporting a role in this disease ranges from basic studies in experimental animals to various other clinical and epidemiological studies. Whilst some epidemiological studies suggest a beneficial role for carotenoids in the prevention of AMD, others are found to be unrelated to it. Results of some clinical studies indicate that the risk for AMD is reduced when levels of the carotenoids are elevated in the serum or diet, but this correlation is not observed in other studies. Published data concerning the toxicity of the carotenoids or the optimum dosage of these supplements is lacking. CONCLUSION An intake of dietary supplied nutrients rich in the carotenoids, lutein and zeaxanthin, appears to be beneficial in protecting retinal tissues, but this is not proven. Until scientifically sound knowledge is available we recommend for patients judged to be at risk for AMD to: alter their diet to more dark green leafy vegetables, wear UV protective lenses and a hat when outdoors. Future investigations on the role of nutrition, light exposure, genetics, and combinations of photodynamic therapy with intravitreal steroid (triamcinolone-acetonide) injections hold potential for future treatment possibilities.
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Affiliation(s)
| | - Stefan Sacu
- Department of Ophthalmology, University of Vienna, Austria
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Hak AE, Stampfer MJ, Campos H, Sesso HD, Gaziano JM, Willett W, Ma J. Plasma carotenoids and tocopherols and risk of myocardial infarction in a low-risk population of US male physicians. Circulation 2003; 108:802-7. [PMID: 12900344 DOI: 10.1161/01.cir.0000084546.82738.89] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Increased intake of carotenoids and vitamin E may protect against myocardial infarction (MI). However, prospective data on blood levels of carotenoids other than beta-carotene and vitamin E (tocopherol) and risk of MI are sparse. METHODS AND RESULTS We conducted a prospective, nested case-control analysis among male physicians without prior history of cardiovascular disease who were followed for up to 13 years in the Physicians' Health Study. Samples from 531 physicians diagnosed with MI were analyzed together with samples from paired control subjects, matched for age and smoking, for 5 major carotenoids (alpha- and beta-carotene, beta-cryptoxanthin, lutein, and lycopene), retinol, and alpha- and gamma-tocopherol. Overall, we found no evidence for a protective effect against MI for higher baseline plasma levels of retinol or any of the carotenoids measured. Among current and former smokers but not among never-smokers, higher baseline plasma levels of beta-carotene tended to be associated with lower risk (P for interaction=0.02). Men with higher plasma levels of gamma-tocopherol tended to have an increased risk of MI (P for trend=0.01). CONCLUSIONS These prospective data do not support an overall protective relation between plasma carotenoids or tocopherols and future MI risk among men without a history of prior cardiovascular disease.
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Affiliation(s)
- A Elisabeth Hak
- Department of Epidemiology, Harvard School of Public Health, Channing Laboratory, 181 Longwood Ave, Boston, Mass 02115-5804, USA
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Tyssandier V, Cardinault N, Caris-Veyrat C, Amiot MJ, Grolier P, Bouteloup C, Azais-Braesco V, Borel P. Vegetable-borne lutein, lycopene, and beta-carotene compete for incorporation into chylomicrons, with no adverse effect on the medium-term (3-wk) plasma status of carotenoids in humans. Am J Clin Nutr 2002; 75:526-34. [PMID: 11864859 DOI: 10.1093/ajcn/75.3.526] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND The results of epidemiologic studies have consistently shown associations between dietary intake or plasma carotenoid status and incidence of cancers and cardiovascular and eye diseases. OBJECTIVE The aim was to assess whether vegetable-borne carotenoids (lycopene, lutein, and beta-carotene) compete for intestinal absorption and whether this affects the plasma status of carotenoids in the medium term (ie, after 3 wk). DESIGN During 3-wk periods separated by 3-wk washout periods, 20 women were supplemented with either 96 g tomato purée/d (14.98 mg lycopene + 1.50 mg beta-carotene), 92 g cooked chopped spinach/d (11.93 mg lutein + 7.96 mg beta-carotene), 96 g tomato purée/d + 92 g chopped spinach/d, 96 g tomato purée/d + 2 lutein pills (12 mg lutein), or 92 g chopped spinach/d + 1 lycopene pill (15 mg lycopene). Plasma carotenoids were measured before and after each supplementation period. The subjects also participated in postprandial experiments in which they ingested meals containing double amounts of the supplements described above. Carotenoids were measured in chylomicrons to assess the interaction of carotenoids on absorption. RESULTS Adding a second carotenoid to a meal that provided a first carotenoid diminished the chylomicron response to the first carotenoid. However, cosupplementation with a second carotenoid of a diet supplemented with a first carotenoid did not diminish the medium-term plasma response to the first carotenoid. CONCLUSION Consumption of carotenoids from different vegetable sources does not diminish plasma carotenoid concentrations in the medium term, despite the finding in postprandial testing of competitive inhibitory interactions among different carotenoids.
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Affiliation(s)
- Viviane Tyssandier
- Unité Maladies Métaboliques et Micronutriments, INRA, Clermont-Ferrand/Theix, Saint-Genès-Champanelle, France
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Meijer EP, Goris AH, Senden J, van Dongen JL, Bast A, Westerterp KR. Antioxidant supplementation and exercise-induced oxidative stress in the 60-year-old as measured by antipyrine hydroxylates. Br J Nutr 2001; 86:569-75. [PMID: 11737955 DOI: 10.1079/bjn2001434] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The effects of 12 weeks of antioxidant supplementation on exercise-induced oxidative stress were investigated in older adults (60 (SE 1) years; BMI 26 (SE 1) kg/m(2)). Subjects were randomly divided in two groups: supplementation (n 11) with 100 mg dl-alpha-tocopheryl acetate, 200 mg ascorbic acid, and 2 mg beta-carotene, and placebo (n 9). Before and after the 12 week supplementation period, subjects cycled for 45 min at submaximal intensity (50 % maximal workload capacity). Antipyrine was used as marker for oxidative stress. Antipyrine reacts quickly with hydroxyl radicals to form para- and ortho-hydroxyantipyrine. The latter metabolite is not formed in man through the mono-oxygenase pathway of cytochrome P450. Daily supplementation significantly increased plasma concentrations of alpha-tocopherol and beta-carotene in the supplemented group (Delta 14.4 (SE 3.2) and 0.4 (se 0.1) micromol/l; P<0.001 and P<0.01). No significant differences, within and between groups, were observed in the exercise-induced increase in the ratios para- and ortho-hydroxyantipyrine to antipyrine. In addition, supplementation did not affect the exercise-induced increase in thiobarbituric acid reactive substances in plasma. In conclusion, in 60-year-old subjects antioxidant supplementation had no effect on the exercise-induced increase in oxidative stress as measured by free radical products of antipyrine.
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Affiliation(s)
- E P Meijer
- Department of Human Biology, Maastricht University, Maastricht, The Netherlands.
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Corridan BM, O'Donoghue M, Hughes DA, Morrissey PA. Low-dose supplementation with lycopene or beta-carotene does not enhance cell-mediated immunity in healthy free-living elderly humans. Eur J Clin Nutr 2001; 55:627-35. [PMID: 11477460 DOI: 10.1038/sj.ejcn.1601187] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2000] [Revised: 01/02/2001] [Accepted: 01/10/2001] [Indexed: 12/27/2022]
Abstract
OBJECTIVE To assess the effects of supplementation with the carotenoids, beta-carotene or lycopene, at levels achievable within a diet rich in fruit and vegetables, on immune function in a group of free-living healthy elderly. DESIGN A double-blind randomized placebo-controlled trial. T cell subsets and the expression of functionally associated cell surface molecules, quantified by flow cytometry, and lectin-stimulated lymphocyte proliferation, were compared before and following the treatment period. SUBJECTS Fifty-eight subjects aged over 65 y were recruited; 52 were included in the final analysis. INTERVENTIONS Participants received one placebo, one lycopene (13.3 mg) or one beta-carotene (8.2 mg) capsule daily for 12 weeks. RESULTS No significant differences were observed in any of the parameters examined following either lycopene or beta-carotene supplementation. CONCLUSIONS In well-nourished, free-living, healthy elderly individuals, supplementation with relatively low levels of beta-carotene or lycopene is not associated with either a beneficial or detrimental effects on several aspects of cell-mediated immunity.
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Affiliation(s)
- B M Corridan
- Nutritional Sciences, Department of Food Science and Technology, University College, Cork, Ireland
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Gimeno E, Castellote AI, Lamuela-Raventós RM, de la Torre-Boronat MC, López-Sabater MC. Rapid high-performance liquid chromatographic method for the simultaneous determination of retinol, alpha-tocopherol and beta-carotene in human plasma and low-density lipoproteins. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 2001; 758:315-22. [PMID: 11486843 DOI: 10.1016/s0378-4347(01)00202-x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A reversed-phase HPLC method with diode-array detection was used to simultaneously determine retinol, alpha-tocopherol and beta-carotene in human plasma and low-density lipoproteins. An aliquot of sample was de-proteinized with ethanol containing beta-tocopherol acetate as internal standard, and the analytes were extracted twice with hexane. The solvent was evaporated to dryness under a stream of nitrogen and the residue was redissolved in methanol to be injected directly into the HPLC system. A multiple solvent system based on methanol, butanol and water at a flow-rate of 2 ml/min and held at 45 degrees C provided clear separation of these compounds in only 8 min. The method showed good linearity, precision and accuracy for all compounds. Owing to its simplicity, this method may be useful in routine clinical and epidemiological work.
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Affiliation(s)
- E Gimeno
- Dpt. Nutricío i Bromatologia, Centre de Referència en Tecnologia dels Aliments, Facultat Fe Farmácia, Universitat de Barcelona, Spain
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Jang Y, Lee JH, Huh KB, Kim OY, Topham D, Balderston B. Influence of alcohol consumption and smoking habits on cardiovascular risk factors and antioxidant status in healthy Korean men. Nutr Res 2000. [DOI: 10.1016/s0271-5317(00)00220-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Martin KR, Wu D, Meydani M. The effect of carotenoids on the expression of cell surface adhesion molecules and binding of monocytes to human aortic endothelial cells. Atherosclerosis 2000; 150:265-74. [PMID: 10856518 DOI: 10.1016/s0021-9150(99)00375-5] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Several large epidemiological studies have shown a correlation between elevated plasma carotenoid levels and decreased risk of cardiovascular disease (CVD). One proposed mechanism for the beneficial effect of carotenoids is through functional modulation of potentially atherogenic processes associated with the vascular endothelium. To test this, we incubated confluent human aortic endothelial cell (HAEC) cultures (passages 4-8) for 24 h with each of the five most prevalent carotenoids in human plasma, which are alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, and lycopene, at an approximate concentration of 1 micromol/l. Carotenoids were solubilized in 0.7% (v/v) tetrahydrofuran and incorporated into FBS before adding to cell culture medium. Due to disparate solubilities in aqueous medium, final concentrations of alpha-carotene, beta-carotene, beta-cryptoxanthin, lutein, and lycopene were 1.7, 1.1, 0.7, 0.9, and 0.3 micromol/l and monolayers accumulated 647, 158, 7, 113, and 9 pmol/mg protein, respectively. Monolayers were then stimulated with IL-1beta (5 ng/ml) for 6 h with subsequent determination of cell surface expression of adhesion molecules as measured by an enzyme-linked immunosorbent assay (ELISA). To assess endothelial cell adhesion to monocytes, IL-1beta-stimulated monolayers were incubated for 10 min with 51Cr-labeled U937 monocytic cells and adhesion determined by isotope counting. Pre-incubation of HAEC with beta-carotene, lutein and lycopene significantly reduced VCAM-1 expression by 29, 28, and 13%, respectively. Pre-incubation with beta-carotene and lutein significantly reduced E-selectin expression by 38 and 34%, respectively. Pre-treatment with beta-carotene, lutein and lycopene significantly reduced the expression of ICAM-1 by 11, 14, and 18%, respectively. While other carotenoids were ineffective, lycopene attenuated both IL-1beta-stimulated and spontaneous HAEC adhesion to U937 monocytic cells by 20 and 25%, respectively. Thus, among the carotenoids, lycopene appears to be most effective in reducing both HAEC adhesion to monocytes and expression of adhesion molecules on the cell surface.
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Affiliation(s)
- K R Martin
- Vascular Biology Program, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, 711 Washington Street, 02111, Boston, MA, USA
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Sasaki S, Tsubono Y, Okubo S, Hayashi M, Kakizoe T, Tsugane S. Effects of three-month oral supplementation of beta-carotene and vitamin C on serum concentrations of carotenoids and vitamins in middle-aged subjects: a pilot study for a randomized controlled trial to prevent gastric cancer in high-risk Japanese population. Jpn J Cancer Res 2000; 91:464-70. [PMID: 10835489 PMCID: PMC5926389 DOI: 10.1111/j.1349-7006.2000.tb00968.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Prior to a randomized controlled trial to prevent gastric cancer by oral supplementation of beta-carotene and vitamin C in a high-risk Japanese population, we examined the serum response to three-month oral supplementation of beta-carotene (0, 3, 30 mg / day) and vitamin C (0, 50, 1000 mg / day) by a three-by-three factorial design using 54 subjects (age range = 40 - 69 years). Serum concentrations of carotenoids, alpha-tocopherol, and ascorbic acid were examined at baseline, and one, two, and three-month points. Both serum beta-carotene and ascorbic acid were significantly higher in high-dose groups than in each placebo group during the supplementation. The serum beta-carotene increased gradually (597 - 830% increase) during the study, whereas the serum ascorbic acid reached nearly a steady-state at the one-month point and remained stable thereafter (88 - 95% increase). No statistically significant interaction between beta-carotene and vitamin C supplementations was observed either for serum beta-carotene or for serum ascorbic acid. Among carotenoids and alpha-tocopherol examined, serum lycopene in the high-dose beta-carotene group was significantly higher than in the placebo group at all points. No unfavorable change in carotenoids and alpha-tocopherol was observed in any group.
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Affiliation(s)
- S Sasaki
- Epidemiology and Biostatistics Division, National Cancer Center Research Institute East, 6-5-1 Kashiwanoha, Kashiwa 277-8577, Japan.
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Evans JR, Henshaw K. Antioxidant vitamin and mineral supplementation for preventing age-related macular degeneration. Cochrane Database Syst Rev 2000:CD000253. [PMID: 10796707 DOI: 10.1002/14651858.cd000253] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Some observational studies have suggested that people who eat a diet rich in antioxidant vitamins (carotenoids, vitamins C and E) or minerals (selenium and zinc) may be less likely to develop age-related macular degeneration. OBJECTIVES The aim of this review is to examine the evidence as to whether or not taking vitamin or mineral supplements prevents the development of age-related macular degeneration. SEARCH STRATEGY We searched the Cochrane Eyes and Vision Group specialised register, the Cochrane Controlled Trials Register - Central, MEDLINE, reference lists of identified reports and the Science Citation Index. We contacted investigators and experts in the field for details of unpublished studies. The most recent searches were conducted in June 1999. SELECTION CRITERIA All randomised trials comparing an antioxidant vitamin and/or mineral supplement (alone or in combination) to control were included. We included only studies where supplementation had been given for at least one year. DATA COLLECTION AND ANALYSIS Both reviewers independently extracted data and assessed trial quality. Currently there is only one published trial included in the review so no data synthesis was conducted. MAIN RESULTS One trial is included in the review. This was a primary prevention trial in Finnish male smokers with four treatment groups: alpha-tocopherol alone, beta-carotene alone, alpha-tocopherol and beta-carotene, placebo. The add-on maculopathy study was conducted in a subset of the main trial cohort. 269 cases of maculopathy (14 late stage age-related macular degeneration) were identified. There was no association of age-related macular degeneration with treatment. REVIEWER'S CONCLUSIONS There is no evidence to date that people without age-related macular degeneration should take antioxidant vitamin and mineral supplements to prevent or delay the onset of the disease. The results of five large ongoing trials are awaited.
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Affiliation(s)
- J R Evans
- 'Glaxo' Department of Ophthalmology Epidemiology, Institute of Ophthalmology (UCL) and Moorfields Eye Hospital, City Road, London, UK, EC1V 2PD.
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Riedl J, Linseisen J, Hoffmann J, Wolfram G. Some dietary fibers reduce the absorption of carotenoids in women. J Nutr 1999; 129:2170-6. [PMID: 10573545 DOI: 10.1093/jn/129.12.2170] [Citation(s) in RCA: 184] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Dietary fiber may be partly responsible for the lower bioavailability of carotenoids from food than from purified supplements. Due to the lack of detailed information available, we investigated the effects of different kinds of dietary fiber on the absorption of carotenoids and alpha-tocopherol. Six healthy young women received an antioxidant mixture consisting of beta-carotene, lycopene, lutein, canthaxanthin and alpha-tocopherol together with a standard meal. The meal did not contain additional dietary fiber or was enriched with pectin, guar, alginate, cellulose or wheat bran (0. 15 g. kg body weight(-1)). The increases in plasma carotenoid and alpha-tocopherol concentrations were followed over 24 h, and the areas-under-curves (AUC(24h)) were calculated. The mean AUC(24h) of beta-carotene was significantly (P < 0.05) reduced by the water-soluble fibers pectin, guar and alginate with a mean decrease of 33-43%. All tested fibers significantly reduced the AUC(24h) of lycopene and lutein by 40-74% (P < 0.05). The dietary fiber effect on the AUC(24h) of canthaxanthin was almost significant (P = 0.059) and there was no effect on the AUC(24h) of alpha-tocopherol. We conclude that the bioavailability of beta-carotene, lycopene and lutein given within a mixed supplement is markedly reduced by different kinds of dietary fiber.
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Affiliation(s)
- J Riedl
- Institute of Nutrition Science, Technical University of Munich, Freising-Weihenstephan, Germany
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Watzl B, Bub A, Brandstetter BR, Rechkemmer G. Modulation of human T-lymphocyte functions by the consumption of carotenoid-rich vegetables. Br J Nutr 1999; 82:383-9. [PMID: 10673911 DOI: 10.1017/s0007114599001634] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
A human intervention study was conducted to determine the effect of the consumption of carotenoid-rich vegetables on the immune system. Subjects, (twenty-three men), who were non-smokers, were not restricted in their daily diet, except that they had to abstain from fruit and vegetables high in carotenoids throughout the whole study period. The study was divided into four periods, each lasting 2 weeks: weeks 1-2: low-carotenoid period; throughout weeks 3-8: daily consumption of 330 ml tomato juice (40 mg lycopene/d, 1.5 mg beta-carotene/d) (weeks 3-4), 330 ml carrot juice (21.6 mg beta-carotene/d, 15.7 mg alpha-carotene/d, 0.5 mg lutein/d) (weeks 5-6), 10 g dried spinach powder (11.3 mg lutein/d, 3.1 mg beta-carotene/d) (weeks 7-8). Blood was collected weekly from subjects after a 12 h fast. T-lymphocyte functions were assessed by measuring proliferation and secretion of immunoreactive cytokines. The consumption of a low-carotenoid diet resulted in a significantly reduced proliferation of peripheral blood mononuclear cells (PBMC) cultured with concanavalin A. After 2 weeks of tomato juice consumption and until the end of the intervention period lymphocyte proliferation was not significantly changed compared with proliferation at the end of the depletion period. Secretion of cytokines by T-helper-1-like lymphocytes (interleukin (IL)-2) and by T-helper-2-like lymphocytes (IL-4) was influenced by the dietary intervention. IL-2 and IL-4 secretion values were significantly suppressed after the low-carotenoid diet (P < 0.001 and P < 0.05 respectively compared with baseline). Tomato juice consumption significantly enhanced IL-2 (P < 0.001) and IL-4 secretion (P < 0.05) compared with the end of depletion period. After carrot juice and spinach powder consumption the cytokine secretion capacity of PBMC was not significantly different from that at the end of the depletion period. In conclusion, the results of the present study indicate that a low-carotenoid diet reduces T-lymphocyte functions and addition of tomato juice restores these functions. This modulation could not be explained by changes in the plasma carotenoid concentrations. The active constituents in tomato juice as well as the biological significance of this immunomodulation remain to be determined.
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Affiliation(s)
- B Watzl
- Institute of Nutritional Physiology, Federal Research Centre for Nutrition, Karlsruhe, Germany.
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Gylling H, Puska P, Vartiainen E, Miettinen TA. Retinol, vitamin D, carotenes and alpha-tocopherol in serum of a moderately hypercholesterolemic population consuming sitostanol ester margarine. Atherosclerosis 1999; 145:279-85. [PMID: 10488954 DOI: 10.1016/s0021-9150(99)00078-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We have shown earlier that sitostanol ester margarine lowers serum cholesterol by inhibiting cholesterol absorption so that, theoretically, there could be interference with the absorption of fat-soluble vitamins. Accordingly, we investigated whether sitostanol ester margarine affects the serum levels of vitamin D, retinol, alpha-tocopherol and alpha- and beta-carotenes during 1-year treatment in 102 subjects and 49 controls with moderate hypercholesterolemia. The vitamins were assayed at baseline on home diet, on margarine alone, after 1 year's consumption of sitostanol ester margarine and after an additional 2 months on home diet. In the sitostanol group, serum plant sterols, indicators of cholesterol absorption efficiency, were reduced up to -38% in relation to controls from home diet (P < 0.01) indicating that cholesterol absorption was markedly reduced. Vitamin D and retinol concentrations and the ratio of alpha-tocopherol to cholesterol were unchanged by sitostanol ester. Serum beta-carotenes and alpha-carotene concentration but not proportion were reduced in the sitostanol group from baseline and in relation to controls (P < 0.01). Retinol and vitamin D were unassociated with serum cholesterol, plant sterols or other vitamins, whereas alpha-tocopherol and carotenes were significantly associated with serum plant sterols suggesting that the higher cholesterol absorption efficiency, the higher the alpha-tocopherol and carotene levels in serum. We conclude that sitostanol ester did not affect vitamin D and retinol concentrations and alpha-tocopherol/cholesterol proportion, but reduced serum beta-carotene levels. Alpha-tocopherol and carotenes, but not vitamin D and retinol, were related to serum cholesterol and cholesterol absorption.
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Affiliation(s)
- H Gylling
- Department of Medicine, University of Helsinki, Finland
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van het Hof KH, Brouwer IA, West CE, Haddeman E, Steegers-Theunissen RP, van Dusseldorp M, Weststrate JA, Eskes TK, Hautvast JG. Bioavailability of lutein from vegetables is 5 times higher than that of beta-carotene. Am J Clin Nutr 1999; 70:261-8. [PMID: 10426704 DOI: 10.1093/ajcn.70.2.261] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND To gain more insight into the relation between vegetable consumption and the risk of chronic diseases, it is important to determine the bioavailability of carotenoids from vegetables and the effect of vegetable consumption on selected biomarkers of chronic diseases. OBJECTIVE To assess the bioavailability of beta-carotene and lutein from vegetables and the effect of increased vegetable consumption on the ex vivo oxidizability of LDL. DESIGN Over 4 wk, 22 healthy adult subjects consumed a high-vegetable diet (490 g/d), 22 consumed a low-vegetable diet (130 g/d), and 10 consumed a low-vegetable diet supplemented with pure beta-carotene (6 mg/d) and lutein (9 mg/d). RESULTS Plasma concentrations of vitamin C and carotenoids (ie, alpha-carotene, beta-carotene, lutein, zeaxanthin, and beta-cryptoxanthin) were significantly higher after the high-vegetable diet than after the low-vegetable diet. In addition to an increase in plasma beta-carotene and lutein, the pure carotenoid-supplemented diet induced a significant decrease in plasma lycopene concentration of -0.11 micromol/L (95% CI: -0.21, -0.0061). The responses of plasma beta-carotene and lutein to the high-vegetable diet were 14% and 67%, respectively, of those to the pure carotenoid- supplemented diet. Conversion of beta-carotene to retinol may have attenuated its plasma response compared with that of lutein. There was no significant effect on the resistance of LDL to oxidation ex vivo. CONCLUSIONS Increased vegetable consumption enhances plasma vitamin C and carotenoid concentrations, but not resistance of LDL to oxidation. The relative bioavailability of lutein from vegetables is higher than that of beta-carotene.
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Dugas TR, Morel DW, Harrison EH. Dietary supplementation with beta-carotene, but not with lycopene, inhibits endothelial cell-mediated oxidation of low-density lipoprotein. Free Radic Biol Med 1999; 26:1238-44. [PMID: 10381195 DOI: 10.1016/s0891-5849(98)00321-9] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Carotenoids may protect low-density lipoprotein from oxidation, a process implicated in the development of atherosclerosis. Our previous studies showed that in vitro enrichment of low-density lipoprotein (LDL) with beta-carotene protected it from cell-mediated oxidation. However, in vitro enrichment with either lutein or lycopene actually enhanced oxidation of the LDL. In the present studies we have examined the impact of LDL carotenoid content on its oxidation by human aortic endothelial cells (EaHy-1) in culture, comparing the effects of in vivo supplementation with in vitro enrichments. The beta-carotene content in human LDL was increased three- to sixfold by daily supplementation with 15 mg beta-carotene for 4 weeks, and the lycopene content of LDL in other individuals was increased two- to threefold by ingestion of one glass (12 ounce) of tomato juice daily for 3 weeks. LDL isolated from these healthy, normolipidemic donors not taking supplemental carotenoid was incubated at 0.25 mg protein/ml with EaHy-1 cells in Ham's F-10 medium for up to 48 h. Following dietary beta-carotene supplementation, LDL oxidation (as assessed by formation of lipid hydroperoxides) was markedly inhibited, to an even greater extent than was observed for LDL enriched in vitro with beta-carotene (that resulted in an 11- to 12-fold increase in LDL beta-carotene). No effect on cell-mediated oxidation was observed, however, for LDL enriched in vivo with lycopene. Thus, beta-carotene appears to function as an antioxidant in protecting LDL from cell-mediated oxidation although lycopene does not. The fact that the three- to sixfold enrichments of LDL with beta-carotene achieved by dietary supplementation were more effective in inhibiting oxidation than the 11- to 12-fold enrichments achieved by an in vitro method suggests that dietary supplementation is a more appropriate procedure for studies involving the enrichment of lipoprotein with carotenoids.
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Affiliation(s)
- T R Dugas
- Department of Biochemistry, MCP Hahnemann School of Medicine, Philadelphia, PA, USA
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Abstract
Our aim was to investigate (1) whether different campestanol/sitostanol mixtures in margarine differ in reducing serum cholesterol, and (2) whether sitostanol ester in butter decreases serum cholesterol and alters cholesterol absorption and metabolism. Twenty-three postmenopausal women replaced 25 g dietary fat with (1) sitostanol ester-rich (campestanol to sitostanol ratio 1:11) and (2) campestanol ester-rich (campestanol to sitostanol ratio 1:2) rapeseed oil margarine, (3) butter, and (4) sitostanol ester-rich (campestanol to sitostanol ratio 1:13) butter. The respective scheduled stanol intake was 3.18, 3.16, and 2.43 g/d. The 6-week margarine periods and, after an 8-week washout, 5-week butter periods were double-blind and in random order. Serum cholesterol precursor sterols (indicators of cholesterol synthesis) and plant sterols (indicators of cholesterol absorption) were quantified with gas-liquid chromatography (GLC). Low-density lipoprotein (LDL) cholesterol was reduced by 8% and 10% with the sitostanol and campestanol ester-rich margarines versus baseline (P < .05 for both) and high-density lipoprotein (HDL) cholesterol was increased by 6% and 5% (P < .05), so the LDL/HDL cholesterol ratio was reduced by 15% (P < .05 for both). Sitostanol ester-rich butter decreased LDL cholesterol 12% and the LDL/HDL cholesterol ratio 11% (P < .05 for both) versus the butter period. The serum proportions of plant sterols and cholestanol were similarly reduced and those of cholesterol precursor sterols were similarly increased during all periods (P < .05 for all). Serum proportions of sitostanol and campestanol were slightly increased, indicating that their absorption related to their dietary intake. During all stanol interventions, serum vitamin D and retinol concentrations and alpha-tocopherol to cholesterol ratios were unchanged, whereas those of alpha- and beta-carotenes were significantly reduced. We conclude that varying the campestanol to sitostanol ratio from 1:13 to 1:2 in margarine and in butter similarly decreased cholesterol absorption, LDL cholesterol, and the LDL/HDL cholesterol ratio such that the serum lipids became less atherogenic.
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Affiliation(s)
- H Gylling
- Department of Medicine, University of Helsinki, Finland
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Abstract
The importance of low density lipoprotein (LDL) oxidation to the atherosclerotic process has led to the examination of beta-carotene as a possible preventive agent. Several epidemiologic studies show an inverse association between serum/adipose beta-carotene levels and coronary heart disease risk. Randomized clinical trials, however, have not shown any benefit, and perhaps even an adverse effect, of beta-carotene supplementation. A number of possible confounding factors may explain the inconsistency between the trials and epidemiologic evidence. Other carotenoids that are correlated with beta-carotene both in the diet and in the blood might be important factors, as might other plant-derived compounds. Alternatively, low serum carotenoid levels may reflect either increased lipoprotein density or the presence of inflammation, both factors emerging as important novel risk factors for coronary heart disease. Whereas the trial results support no preventive role for beta-carotene, the epidemiologic evidence does generally support the idea that a diet rich in high carotenoid foods is associated with a reduced risk of heart disease.
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Affiliation(s)
- S B Kritchevsky
- Department of Preventive Medicine, University of Tennessee, Memphis, Memphis, TN 38105, USA
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Abstract
Interactions between carotenoids during absorption and during postabsorptive metabolism have been demonstrated or suggested in animal and human feeding or supplementation studies, as well as in in vitro studies of intestinal beta-carotene cleavage. Much of the evidence suggests an interaction between beta-carotene and oxycarotenoids such as canthaxanthin and lutein, and between the hydrocarbon carotenoids beta-carotene and lycopene. The evidence is equivocal, however, with discrepant findings between studies, both in magnitude and in direction of the interactions observed. This review discusses studies of carotenoid interactions and explores the possible underlying mechanisms and implications of these interactions. The most likely explanations for carotenoid interactions appear to be competition for incorporation into micelles, carotenoid exchange between lipoproteins in the postprandial state, and inhibition of provitamin A (beta-carotene) cleavage.
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Affiliation(s)
- H van den Berg
- Department of Physiology, TNO Nutrition and Food Research Institute, Zeist, The Netherlands
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Abstract
Factors that influence the bioavailability of carotenoids and their bioconversion to retinol are species of carotenoids, molecular linkage, amount of carotenoids consumed in a meal, matrix in which the carotenoid is incorporated, effectors of absorption and bioconversion, nutrient status of the host, genetic factors, host related factors, and mathematical interactions. In this paper, current knowledge of these factors is examined. Although data are not sufficiently comparable to allow an extensive systematic comparison of results, a number of conclusions can be drawn from the information available.
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Affiliation(s)
- J J Castenmiller
- Department of Food Technology and Nutritional Sciences, Wageningen Agricultural University, The Netherlands
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Palan PR, Chang CJ, Mikhail MS, Ho GY, Basu J, Romney SL. Plasma concentrations of micronutrients during a nine-month clinical trial of beta-carotene in women with precursor cervical cancer lesions. Nutr Cancer 1998; 30:46-52. [PMID: 9507512 DOI: 10.1080/01635589809514639] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The effects of oral supplementation of a 30-mg dose of beta-carotene on the plasma levels of carotenoids, tocopherols, and retinol were studied sequentially in 69 patients participating in a nine-month randomized placebo controlled trial conducted to examine efficacy of beta-carotene to induce regression of cervical intraepithelial neoplasia. At each visit (baseline and 1.5, 3, 6, 9, 10.5, and 15 mo), blood samples were collected and the levels of six micronutrients were determined by high-performance liquid chromatography. No limitations or changes were introduced in each participant's dietary habits. Cervico-vaginal lavage samples were also obtained at the same visit and assayed for the presence of human papillomavirus DNA by Southern blot hybridization and polymerase chain reaction. In the supplemented group, mean plasma beta-carotene levels were significantly higher (p = 0.0001) than baseline and remained markedly elevated for 15 months. In the longitudinal analysis of the placebo group, there were no variations among individual mean plasma levels of beta-carotene, alpha-carotene, lycopene, retinol, gamma-tocopherol, or alpha-tocopherol, suggesting absence of seasonal or dietary changes. In the placebo group, cigarette smoking and steroid contraceptive use were significantly associated with low levels of plasma beta-carotene (p = 0.05 and p = 0.012, respectively). However, in contrast, in the beta-carotene-supplemented group, steroid contraceptive use had no influence on the plasma beta-carotene levels. An additional noteworthy finding was that beta-carotene supplementation did not reverse the depletion effect in smokers. There was no association between the plasma levels of these six micronutrients in women with cervical intraepithelial neoplasia and persistent human papillomavirus infection status in the placebo or the supplemented groups. Functional sequential nutrient interactions with each other or with other essential micronutrients and possible long-term toxicity need to be addressed in clinical trials.
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Affiliation(s)
- P R Palan
- Department of Obstetrics and Gynecology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, NY 10461, USA
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Albanes D, Virtamo J, Taylor PR, Rautalahti M, Pietinen P, Heinonen OP. Effects of supplemental beta-carotene, cigarette smoking, and alcohol consumption on serum carotenoids in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. Am J Clin Nutr 1997; 66:366-72. [PMID: 9250116 DOI: 10.1093/ajcn/66.2.366] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
We determined whether serum carotenoid or retinol concentrations were altered by beta-carotene supplementation in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study and whether such effects were modified by alcohol consumption or cigarette use. Participants in this substudy were 491 randomly selected men aged 58-76 y from the metropolitan Helsinki study center [237 receiving supplemental beta-carotene (20 mg/d) and 254 not receiving such supplementation]. Dietary carotenoids, retinol, and alcohol, and serum beta-carotene, alpha-tocopherol, retinol, and cholesterol were assessed at baseline. After an average of 6.7 y of supplementation, serum was collected and carotenoid, retinol, and alpha-tocopherol concentrations were determined by HPLC. Serum carotenoid fractions were highly correlated with each other (P < or = 0.0001). Compared with the unsupplemented group, the beta-carotene group had significantly higher serum concentrations of beta-carotene (1483%), alpha-carotene (145%), and beta-cryptoxanthin (67%) (P < or = 0.0001). Retinol concentrations were 6% higher (P = 0.03) and lutein was 11% lower (P = 0.02) in the supplemented group. Serum lycopene, zeaxanthin, and alpha-tocopherol did not differ according to beta-carotene-supplementation status. Although these beta-carotene-group differences were not significantly altered by amount of alcohol consumption, higher consumption (> 12.9 g/d, median) was related to lower (10-38%) concentrations of carotenoids, particularly beta-carotene, alpha-carotene, and beta-cryptoxanthin, in both the supplemented and unsupplemented groups. Smoking status did not significantly influence the supplementation-related differences in serum carotenoid and retinol values but concentrations of carotenoids were generally highest in participants who quit smoking while in the study and lowest in current smokers of > or = 20 cigarettes/d. This study showed that serum concentrations of non-beta-carotene carotenoids are altered by long-term beta-carotene supplementation and confirms the adverse effects of alcohol and cigarette smoking on serum carotenoids.
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Affiliation(s)
- D Albanes
- National Cancer Institute, Bethesda, MD 20892, USA
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