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Mathar D, Erfanian Abdoust M, Marrenbach T, Tuzsus D, Peters J. The catecholamine precursor Tyrosine reduces autonomic arousal and decreases decision thresholds in reinforcement learning and temporal discounting. PLoS Comput Biol 2022; 18:e1010785. [PMID: 36548401 PMCID: PMC9822114 DOI: 10.1371/journal.pcbi.1010785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 01/06/2023] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Supplementation with the catecholamine precursor L-Tyrosine might enhance cognitive performance, but overall findings are mixed. Here, we investigate the effect of a single dose of tyrosine (2g) vs. placebo on two catecholamine-dependent trans-diagnostic traits: model-based control during reinforcement learning (2-step task) and temporal discounting, using a double-blind, placebo-controlled, within-subject design (n = 28 healthy male participants). We leveraged drift diffusion models in a hierarchical Bayesian framework to jointly model participants' choices and response times (RTS) in both tasks. Furthermore, comprehensive autonomic monitoring (heart rate, heart rate variability, pupillometry, spontaneous eye blink rate) was performed both pre- and post-supplementation, to explore potential physiological effects of supplementation. Across tasks, tyrosine consistently reduced participants' RTs without deteriorating task-performance. Diffusion modeling linked this effect to attenuated decision-thresholds in both tasks and further revealed increased model-based control (2-step task) and (if anything) attenuated temporal discounting. On the physiological level, participants' pupil dilation was predictive of the individual degree of temporal discounting. Tyrosine supplementation reduced physiological arousal as revealed by increases in pupil dilation variability and reductions in heart rate. Supplementation-related changes in physiological arousal predicted individual changes in temporal discounting. Our findings provide first evidence that tyrosine supplementation might impact psychophysiological parameters, and suggest that modeling approaches based on sequential sampling models can yield novel insights into latent cognitive processes modulated by amino-acid supplementation.
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Affiliation(s)
- David Mathar
- Department of Psychology, Biological Psychology, University of Cologne, Cologne, Germany
- * E-mail:
| | - Mani Erfanian Abdoust
- Biological Psychology of Decision Making, Institute of Experimental Psychology, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
| | - Tobias Marrenbach
- Biological Psychology of Decision Making, Institute of Experimental Psychology, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
| | - Deniz Tuzsus
- Department of Psychology, Biological Psychology, University of Cologne, Cologne, Germany
| | - Jan Peters
- Department of Psychology, Biological Psychology, University of Cologne, Cologne, Germany
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Ma Q, Gao F, Zhou L, Fan Y, Zhao B, Xi W, Wang C, Zhu F, Ma X, Wang W, Wang Y. Characterizing serum amino acids in schizophrenic patients: Correlations with gut microbes. J Psychiatr Res 2022; 153:125-133. [PMID: 35810602 DOI: 10.1016/j.jpsychires.2022.07.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Revised: 06/02/2022] [Accepted: 07/01/2022] [Indexed: 10/17/2022]
Abstract
Amino acid abnormalities have been suggested to be a key pathophysiological mechanism in schizophrenia (SZ). Recently, gut microbes were found to be critically involved in mental and metabolic diseases. However, the relationship between serum amino acid levels and gut microbes in SZ is rarely studied. Here, we analyzed serum amino acid levels in 76 untreated SZ patients and 79 healthy controls (HC). Serum levels of 10 amino acids were significantly altered in patients with SZ. We further classified the cut-off values for serum arginine, leucine, glutamine, and methionine levels to distinguish SZ patients from controls. These classifiers were shown to be effective in another validation cohort (49 SZ and 48 HC). The correlation between serum amino acids and clinical symptoms and cognitive functions was also analyzed. Arginine, leucine, glutamine, and methionine levels were significantly correlated with clinical symptoms and cognitive impairments in SZ patients. By metagenome shotgun sequencing of fecal samples, we found that patients with SZ with a low level of serum amino acids have higher richness and evenness of the gut microbiota. At the genus level, the abundances of Mitsuokella and Oscillibacter are significantly abnormal. At the mOTU level, 15 mOTUs in the low-level SZ group were significantly different from the HC group. In addition, Mitsuokella multacida was correlated with glutamine and methionine, respectively. Our research revealed that alterations in serum amino acid levels are critically related to changes in gut microbiota composition in SZ patients. These findings may shed light on new strategies for the diagnosis and treatment of SZ.
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Affiliation(s)
- Qingyan Ma
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Clinical Research Center for Psychiatric Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China
| | - Fengjie Gao
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Clinical Research Center for Psychiatric Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China
| | - Lina Zhou
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Clinical Research Center for Psychiatric Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China
| | - Yajuan Fan
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Clinical Research Center for Psychiatric Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China
| | - Binbin Zhao
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Clinical Research Center for Psychiatric Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China
| | - Wenyu Xi
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Clinical Research Center for Psychiatric Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China
| | - Chuyao Wang
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Clinical Research Center for Psychiatric Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China
| | - Feng Zhu
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Clinical Research Center for Psychiatric Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Translational Medicine, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, 710061, China
| | - Xiancang Ma
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Clinical Research Center for Psychiatric Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China
| | - Wei Wang
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Clinical Research Center for Psychiatric Medicine of Shaanxi Province, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China.
| | - Yunpeng Wang
- Department of Psychiatry, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China; Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, 277 Yanta West Road, Xi'an, 710061, China.
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Brecht AK, Medawar E, Thieleking R, Sacher J, Beyer F, Villringer A, Witte AV. Dietary and serum tyrosine, white matter microstructure and inter-individual variability in executive functions in overweight adults: Relation to sex/gender and age. Appetite 2022; 178:106093. [PMID: 35738483 DOI: 10.1016/j.appet.2022.106093] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 03/16/2022] [Accepted: 05/19/2022] [Indexed: 11/02/2022]
Abstract
Tyrosine (tyr), the precursor of the neurotransmitter dopamine, is known to modulate cognitive functions including executive attention. Tyr supplementation is suggested to influence dopamine-modulated cognitive performance. However, results are inconclusive regarding the presence or strength and also the direction of the association between tyr and cognitive function. This pre-registered cross-sectional analysis investigates whether diet-associated serum tyr relates to executive attention performance, and whether this relationship is moderated by differences in white matter microstructure. 59 healthy, overweight, young to middle-aged adults (20 female, 28.3 ± 6.6 years, BMI: 27.3 ± 1.5 kg/m2) drawn from a longitudinal study reported dietary habits, donated blood and completed diffusion-weighted brain magnetic resonance imaging and the attention network test. Main analyses were performed using linear regressions and non-parametric voxel-wise inference testing. Confirmatory analyses did neither support an association between dietary and serum tyr nor a relationship between relative serum tyr/large neutral amino acids (LNAA) levels or white matter microstructure and executive attention performance. However, exploratory analyses revealed higher tyr intake, higher serum tyr and better executive attention performance in the male sex/gender group. In addition, older age was associated with higher dietary tyr intake and lower fractional anisotropy in a widespread cluster across the brain. Finally, a positive association between relative serum tyr/LNAA and executive attention performance was found in the male sex/gender group when accounting for age effects. Our analysis advances the field of dopamine-modulated cognitive functions by revealing sex/gender and age differences which might be diet-related. Longitudinal or intervention studies and larger sample sizes are needed to provide more reliable evidence for links between tyr and executive attention.
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Affiliation(s)
- A-K Brecht
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - E Medawar
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - R Thieleking
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany
| | - J Sacher
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Cognitive Neurology, University Medical Center Leipzig, Germany
| | - F Beyer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Cognitive Neurology, University Medical Center Leipzig, Germany
| | - A Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Cognitive Neurology, University Medical Center Leipzig, Germany
| | - A V Witte
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany; Cognitive Neurology, University Medical Center Leipzig, Germany.
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Medrano M, Molina-Hidalgo C, Alcantara JMA, Ruiz JR, Jurado-Fasoli L. Acute Effect of a Dietary Multi-Ingredient Nootropic as a Cognitive Enhancer in Young Healthy Adults: A Randomized, Triple-Blinded, Placebo-Controlled, Crossover Trial. Front Nutr 2022; 9:858910. [PMID: 35634417 PMCID: PMC9133906 DOI: 10.3389/fnut.2022.858910] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
Aim To study the acute effect of a dietary multi-ingredient nootropic on cognitive performance in young healthy adults. We also analyzed the influence of the dietary multi-ingredient nootropic on emotional state, heart rate (HR), and heart rate variability (HRV). Methods This is a randomized, triple-blinded, placebo-controlled, crossover trial. In total, 26 young healthy adults (50% women; 24.9 ± 3.3 years old) ingested 10 g of a dietary multi-ingredient nootropic [Evo-Gamers®; Harrison Sport Nutrition (HSN), Granada, Spain] or placebo (maltodextrin) in a randomized order (clinicaltrials.gov No. NCT04790188). After 30 min of the ingestion, participants performed a battery of cognitive performance tests to measure the processing speed, inhibitory control, working memory, cognitive flexibility, creativity, and verbal fluency. The emotional status was assessed through questionnaires, and HR and HRV were measured using a heart rate monitor. Results In comparison with placebo, the acute ingestion of the nootropic showed a significantly better response time in several cognitive tests (i.e., processing speed, inhibitory control, spatial working memory, and cognitive flexibility, all P < 0.05 and effect size range of 0.4–0.6). It also displayed a higher accuracy in the processing speed, the inhibitory control, and cognitive flexibility tests (all P < 0.05; effect size ranged from 0.4 to 0.6). Furthermore, the nootropic showed a higher creativity and positive emotions and lower sadness-depression emotions, whereas HR and HRV remained similar between placebo vs. nootropic conditions. However, there were no differences between the nootropic and placebo in verbal fluency, motivation, or anxiety (all P > 0.05). Conclusion An acute ingestion of a dietary multi-ingredient nootropic enhances cognitive performance in comparison with placebo without negatively influencing HR or HRV in young healthy adults.
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Affiliation(s)
- María Medrano
- PROmoting FITness and Health Through Physical Activity Research Group, Department of Physical Education and Sports, Faculty of Sport Sciences, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
| | - Cristina Molina-Hidalgo
- PROmoting FITness and Health Through Physical Activity Research Group, Department of Physical Education and Sports, Faculty of Sport Sciences, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
- Department of Physiology, Faculty of Medicine, University of Granada, Granada, Spain
| | - Juan M. A. Alcantara
- PROmoting FITness and Health Through Physical Activity Research Group, Department of Physical Education and Sports, Faculty of Sport Sciences, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
| | - Jonatan R. Ruiz
- PROmoting FITness and Health Through Physical Activity Research Group, Department of Physical Education and Sports, Faculty of Sport Sciences, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
- Instituto de Investigación Biosanitaria, ibs.Granada, Granada, Spain
| | - Lucas Jurado-Fasoli
- PROmoting FITness and Health Through Physical Activity Research Group, Department of Physical Education and Sports, Faculty of Sport Sciences, Sport and Health University Research Institute (iMUDS), University of Granada, Granada, Spain
- Department of Physiology, Faculty of Medicine, University of Granada, Granada, Spain
- *Correspondence: Lucas Jurado-Fasoli,
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Baseline-dependent effect of dopamine's precursor L-tyrosine on working memory gating but not updating. COGNITIVE AFFECTIVE & BEHAVIORAL NEUROSCIENCE 2021; 20:521-535. [PMID: 32133585 PMCID: PMC7266860 DOI: 10.3758/s13415-020-00783-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Adaptive goal-directed behavior requires a dynamic balance between maintenance and updating within working memory (WM). This balance is controlled by an input-gating mechanism implemented by dopamine in the basal ganglia. Given that dopaminergic manipulations can modulate performance on WM-related tasks, it is important to gain mechanistic insight into whether such manipulations differentially affect updating (i.e., encoding and removal) and the closely-related gate opening/closing processes that respectively enable/prevent updating. To clarify this issue, 2.0 g of dopamine’s precursor L-tyrosine was administered to healthy young adults (N = 45) in a double-blind, placebo-controlled, within-subjects study. WM processes were empirically distinguished using the reference-back paradigm, which isolates performance related to updating, gate opening, and gate closing. L-tyrosine had a selective, baseline-dependent effect only on gate opening, which was evidenced by markedly reduced variance across subjects in gate opening performance in the L-tyrosine compared with the placebo condition, whereas the whole-sample average performance did not differ between conditions. This indicates a pattern of results whereby low-performing subjects improved, whereas high-performing subjects were impaired on L-tyrosine. Importantly, this inverted U-shaped pattern was not explained by regression to the mean. These results are consistent with an inverted-U relationship between dopamine and WM, and they indicate that updating and gating are differentially affected by a dopaminergic manipulation. This highlights the importance of distinguishing these processes when studying WM, for example, in the context of WM deficits in disorders with a dopaminergic pathophysiology.
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Klaschik S, Ellerkmann RK, Gehlen J, Frede S, Hilbert T. From bench to bar side: Evaluating the red wine storage lesion. Open Life Sci 2021; 16:872-883. [PMID: 34522781 PMCID: PMC8402936 DOI: 10.1515/biol-2021-0089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/18/2021] [Accepted: 07/19/2021] [Indexed: 11/15/2022] Open
Abstract
Vitally essential red fluids like packed cells and red wine are seriously influenced in quality when stored over prolonged periods. In the case of red cell concentrates, the resulting storage lesion has particular significance in perioperative medicine. We hypothesized that, in contrast, aging rather improves the properties of red wine in several ways. A translational approach, including (I) in vitro experiments, (II) a randomized, blinded crossover trial of acute clinical effects, and (III) a standardized red wine blind tasting was used. Three monovarietal wines (Cabernet Sauvignon, Chianti, Shiraz) in three different vintages (range 2004-2016), each 5 years different, were assessed. Assessments were performed at a German university hospital (I, II) and on a garden terrace during a mild summer evening (III). Young wines induced cell stress and damage while significantly reducing cytoprotective proteins in HepG2 hepatoma cells. Sympathetic activity and multitasking skills were altered depending on wines' ages. Hangovers tended to be aggravated by young red wine. Aged variants performed better in terms of aroma and overall quality but worse in optical appearance. We found no evidence for a red wine storage lesion. However, we plead for consensus-based guidelines for proper storage, as it is common in clinical medicine.
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Affiliation(s)
- Sven Klaschik
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Richard K. Ellerkmann
- Department of Anesthesiology and Intensive Care Medicine, Dortmund Hospital, Beurhausstrasse 40, 44137 Dortmund, Germany
| | - Jennifer Gehlen
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Stilla Frede
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Tobias Hilbert
- Department of Anesthesiology and Intensive Care Medicine, University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
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Crawford C, Boyd C, Deuster PA. Dietary Supplement Ingredients for Optimizing Cognitive Performance Among Healthy Adults: A Systematic Review. J Altern Complement Med 2021; 27:940-958. [PMID: 34370563 DOI: 10.1089/acm.2021.0135] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Background: Dietary supplements promoted for brain health and enhanced cognitive performance are widely available. Claims made for these products are directed not only to the elderly wishing to prevent or mitigate cognitive decline, but also young healthy populations looking to boost their cognitive performance. It is unclear whether these claims made on product bottles and through advertising match the science. Objectives: To explore the evidence on the efficacy and safety of single dietary supplement ingredients frequently marketed with claims of enhanced cognitive performance among healthy adults. Design: A systematic review. Results: Nine of 54 dietary supplement ingredients identified through a scoping review met the eligibility criteria with at least 3 published studies identified per ingredient, yielding 69 unique publications. Ingredients evaluated included Bacopa monnieri, choline, creatine, omega-3 fatty acids, Ginkgo biloba, ginseng, Rhodiola rosea, tyrosine, and valerian root, all in supplement form and compared with a placebo, at various serving sizes and durations of use. Conclusions: The low level of certainty in the state of the science, coupled with not always knowing what is in a dietary supplement product, make weighing risks and benefits difficult; these data hinder the ability to develop recommendations about using such ingredients for consumers interested in boosting their cognitive performance. Whereas certain trends regarding promising serving sizes or duration for use, are pointed to in this synthesis, when combined, studies are inconsistent and imprecise, and many are methodologically flawed. Potential solutions to address research gaps are offered, for future research next steps, which is needed to strengthen the evidence and inform decisions.
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Affiliation(s)
- Cindy Crawford
- Consortium for Health and Military Performance, Department of Military and Emergency Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Courtney Boyd
- Consortium for Health and Military Performance, Department of Military and Emergency Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, USA.,Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Patricia A Deuster
- Consortium for Health and Military Performance, Department of Military and Emergency Medicine, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, MD, USA
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Plini ERG, O’Hanlon E, Boyle R, Sibilia F, Rikhye G, Kenney J, Whelan R, Melnychuk MC, Robertson IH, Dockree PM. Examining the Role of the Noradrenergic Locus Coeruleus for Predicting Attention and Brain Maintenance in Healthy Old Age and Disease: An MRI Structural Study for the Alzheimer's Disease Neuroimaging Initiative. Cells 2021; 10:1829. [PMID: 34359997 PMCID: PMC8306442 DOI: 10.3390/cells10071829] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 07/08/2021] [Accepted: 07/08/2021] [Indexed: 12/18/2022] Open
Abstract
The noradrenergic theory of Cognitive Reserve (Robertson, 2013-2014) postulates that the upregulation of the locus coeruleus-noradrenergic system (LC-NA) originating in the brainstem might facilitate cortical networks involved in attention, and protracted activation of this system throughout the lifespan may enhance cognitive stimulation contributing to reserve. To test the above-mentioned theory, a study was conducted on a sample of 686 participants (395 controls, 156 mild cognitive impairment, 135 Alzheimer's disease) investigating the relationship between LC volume, attentional performance and a biological index of brain maintenance (BrainPAD-an objective measure, which compares an individual's structural brain health, reflected by their voxel-wise grey matter density, to the state typically expected at that individual's age). Further analyses were carried out on reserve indices including education and occupational attainment. Volumetric variation across groups was also explored along with gender differences. Control analyses on the serotoninergic (5-HT), dopaminergic (DA) and cholinergic (Ach) systems were contrasted with the noradrenergic (NA) hypothesis. The antithetic relationships were also tested across the neuromodulatory subcortical systems. Results supported by Bayesian modelling showed that LC volume disproportionately predicted higher attentional performance as well as biological brain maintenance across the three groups. These findings lend support to the role of the noradrenergic system as a key mediator underpinning the neuropsychology of reserve, and they suggest that early prevention strategies focused on the noradrenergic system (e.g., cognitive-attentive training, physical exercise, pharmacological and dietary interventions) may yield important clinical benefits to mitigate cognitive impairment with age and disease.
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Affiliation(s)
- Emanuele R. G. Plini
- Department of Psychology, Trinity College Institute of Neuroscience, Trinity College Dublin, Llyod Building, 42A Pearse St, 8PVX+GJ Dublin, Ireland; (E.O.); (R.B.); (G.R.); (J.K.); (M.C.M.); (I.H.R.); (P.M.D.)
| | - Erik O’Hanlon
- Department of Psychology, Trinity College Institute of Neuroscience, Trinity College Dublin, Llyod Building, 42A Pearse St, 8PVX+GJ Dublin, Ireland; (E.O.); (R.B.); (G.R.); (J.K.); (M.C.M.); (I.H.R.); (P.M.D.)
- Department of Psychiatry, Royal College of Surgeons in Ireland, Hospital Rd, Beaumont, 9QRH+4F Dublin, Ireland
- Department of Psychiatry, School of Medicine Dublin, Trinity College Dublin, 152-160 Pearse St, 8QV3+99 Dublin, Ireland;
| | - Rory Boyle
- Department of Psychology, Trinity College Institute of Neuroscience, Trinity College Dublin, Llyod Building, 42A Pearse St, 8PVX+GJ Dublin, Ireland; (E.O.); (R.B.); (G.R.); (J.K.); (M.C.M.); (I.H.R.); (P.M.D.)
| | - Francesca Sibilia
- Department of Psychiatry, School of Medicine Dublin, Trinity College Dublin, 152-160 Pearse St, 8QV3+99 Dublin, Ireland;
| | - Gaia Rikhye
- Department of Psychology, Trinity College Institute of Neuroscience, Trinity College Dublin, Llyod Building, 42A Pearse St, 8PVX+GJ Dublin, Ireland; (E.O.); (R.B.); (G.R.); (J.K.); (M.C.M.); (I.H.R.); (P.M.D.)
| | - Joanne Kenney
- Department of Psychology, Trinity College Institute of Neuroscience, Trinity College Dublin, Llyod Building, 42A Pearse St, 8PVX+GJ Dublin, Ireland; (E.O.); (R.B.); (G.R.); (J.K.); (M.C.M.); (I.H.R.); (P.M.D.)
| | - Robert Whelan
- Department of Psychology, Global Brain Health Institute, Trinity College Dublin, Lloyd Building, 42A Pearse St, 8PVX+GJ Dublin, Ireland;
| | - Michael C. Melnychuk
- Department of Psychology, Trinity College Institute of Neuroscience, Trinity College Dublin, Llyod Building, 42A Pearse St, 8PVX+GJ Dublin, Ireland; (E.O.); (R.B.); (G.R.); (J.K.); (M.C.M.); (I.H.R.); (P.M.D.)
| | - Ian H. Robertson
- Department of Psychology, Trinity College Institute of Neuroscience, Trinity College Dublin, Llyod Building, 42A Pearse St, 8PVX+GJ Dublin, Ireland; (E.O.); (R.B.); (G.R.); (J.K.); (M.C.M.); (I.H.R.); (P.M.D.)
- Department of Psychology, Global Brain Health Institute, Trinity College Dublin, Lloyd Building, 42A Pearse St, 8PVX+GJ Dublin, Ireland;
| | - Paul M. Dockree
- Department of Psychology, Trinity College Institute of Neuroscience, Trinity College Dublin, Llyod Building, 42A Pearse St, 8PVX+GJ Dublin, Ireland; (E.O.); (R.B.); (G.R.); (J.K.); (M.C.M.); (I.H.R.); (P.M.D.)
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Wu D, Yang CC, Chen KY, Lin YC, Wu PJ, Hsieh PH, Nakao Y, Ow MYL, Hsieh YC, Hu CJ. Hydrolyzed Chicken Extract (ProBeptigen ®) on Cognitive Function in Healthy Middle-Aged People: A Randomized Double-Blind Trial. Nutrients 2020; 12:nu12051362. [PMID: 32397609 PMCID: PMC7284526 DOI: 10.3390/nu12051362] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/07/2020] [Accepted: 05/09/2020] [Indexed: 12/16/2022] Open
Abstract
Cognitive decline is an important issue of global public health. Cognitive aging might begin at middle adulthood, the period particularly vulnerable to stress in lifespan. Essence of chicken (EOC) has consistently demonstrated its beneficial effects on various cognitive domains as nutritional supplementation. This study primarily aimed to examine the cognitive enhancement effects of ProBeptigen® (previously named CMI-168), hydrolyzed peptides extracted from EOC, in healthy middle-aged people under mild stress. Ninety healthy subjects were randomly assigned into the ProBeptigen® or placebo group for eight weeks. Neurocognitive assessment, event-related potentials (ERPs), and blood tests were conducted before, during, and after the treatment. The ProBeptigen® group outperformed placebo group on Logical Memory subtests of Wechsler Memory Scale-third edition (WMS-III) and Spatial Working Memory task in the Cambridge Neuropsychological Test Automated Battery (CANTAB). The anti-inflammatory effects of ProBeptigen® in humans were also confirmed, with progressively declining high-sensitivity C-reactive protein (hs-CRP) levels. Regular dietary supplementation of ProBeptigen® is suggested to improve verbal short- and long-term memory as well as spatial working memory, and reduce inflammation in middle-aged healthy individuals with stress. The effects of ProBeptigen® on cognition warrant further investigation. (NCT03612752)
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Affiliation(s)
- Dean Wu
- Department of Neurology, Shuang-Ho Hospital, Taipei Medical University, New Taipei 235, Taiwan; (D.W.); (C.-C.Y.); (K.-Y.C.); (P.-J.W.); (P.-H.H.)
- School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
| | - Cheng-Chang Yang
- Department of Neurology, Shuang-Ho Hospital, Taipei Medical University, New Taipei 235, Taiwan; (D.W.); (C.-C.Y.); (K.-Y.C.); (P.-J.W.); (P.-H.H.)
- Research Center for Brain and Consciousness, Taipei Medical University, Taipei 235, Taiwan
| | - Kuan-Yu Chen
- Department of Neurology, Shuang-Ho Hospital, Taipei Medical University, New Taipei 235, Taiwan; (D.W.); (C.-C.Y.); (K.-Y.C.); (P.-J.W.); (P.-H.H.)
| | - Ying-Chin Lin
- School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
- Department of Family Medicine, Wanfang Hospital, Taipei 116, Taiwan
| | - Pei-Jung Wu
- Department of Neurology, Shuang-Ho Hospital, Taipei Medical University, New Taipei 235, Taiwan; (D.W.); (C.-C.Y.); (K.-Y.C.); (P.-J.W.); (P.-H.H.)
| | - Pei-Hsiu Hsieh
- Department of Neurology, Shuang-Ho Hospital, Taipei Medical University, New Taipei 235, Taiwan; (D.W.); (C.-C.Y.); (K.-Y.C.); (P.-J.W.); (P.-H.H.)
| | - Yoshihiro Nakao
- Research and Development, BRAND’S Suntory Asia, Singapore 138623, Singapore; (Y.N.); (M.Y.L.O.)
| | - Mandy Y. L. Ow
- Research and Development, BRAND’S Suntory Asia, Singapore 138623, Singapore; (Y.N.); (M.Y.L.O.)
| | - Yi-Chen Hsieh
- PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan
- Correspondence: (Y.-C.H.); (C.-J.H.)
| | - Chaur-Jong Hu
- Department of Neurology, Shuang-Ho Hospital, Taipei Medical University, New Taipei 235, Taiwan; (D.W.); (C.-C.Y.); (K.-Y.C.); (P.-J.W.); (P.-H.H.)
- School of Medicine, College of Medicine, Taipei Medical University, Taipei 110, Taiwan;
- PhD Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei 110, Taiwan
- Correspondence: (Y.-C.H.); (C.-J.H.)
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10
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Tyrosine negatively affects flexible-like behaviour under cognitively demanding conditions. J Affect Disord 2020; 260:329-333. [PMID: 31521870 DOI: 10.1016/j.jad.2019.09.031] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 08/06/2019] [Accepted: 09/03/2019] [Indexed: 10/26/2022]
Abstract
BACKGROUND The catecholaminergic precursor to dopamine, tyrosine, is an important modulator of cognitive performance. A number of studies have demonstrated that the beneficial effects of tyrosine on cognitive performance are most pronounced when individuals are exposed to stressful situations, such as hypothermia. However, little is known about whether manipulation of stress using non-aversive stimuli, such as cognitive demand, can also bring about similar improvements. METHODS We conducted a randomized, double-blind, placebo-controlled experiment to test the effects of tyrosine administration and cognitive load (low or high) on cognitive flexibility, a measure known to be influenced by catecholaminergic function. A total of 70 healthy volunteers completed a baseline cognitive flexibility test (Wisconsin Card Sorting Test: WCST). Participants were given a dose of either tyrosine (2.0 g) or placebo (cellulose) and subject to either low cognitive load (simple reaction time task) or high cognitive load (digit memory span task), immediately followed by a WCST for a second time. RESULTS Contrary to expectations, we found that instead of ameliorating performance under the high cognitive load condition, tyrosine worsened cognitive flexibility. LIMITATIONS Physiological marker of stress was not measured. CONCLUSIONS Our results suggest that aversive stressors and cognitive demand modulate the effects of tyrosine on cognitive performance in a differential manner.
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11
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Influence of nutritional tyrosine on cognition and functional connectivity in healthy old humans. Neuroimage 2019; 193:139-145. [DOI: 10.1016/j.neuroimage.2019.03.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/25/2019] [Accepted: 03/04/2019] [Indexed: 01/16/2023] Open
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12
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Nelson JM, Phillips CA, McKinley RA, McIntire LK, Goodyear C, Monforton L. The effects of transcranial direct current stimulation (tDCS) on multitasking performance and oculometrics. MILITARY PSYCHOLOGY 2019. [DOI: 10.1080/08995605.2019.1598217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
| | - Chandler A. Phillips
- Department of Industrial and Biomedical Engineering, Wright State University, Dayton, Ohio
| | - R. Andy McKinley
- Applied Neuroscience Branch, Wright-Patterson Air Force Base, Ohio
| | | | | | - Lanie Monforton
- Department of Industrial and Biomedical Engineering, Wright State University, Dayton, Ohio
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Jo M, Noh MH, Lim HG, Kang CW, Im DK, Oh MK, Jung GY. Precise tuning of the glyoxylate cycle in Escherichia coli for efficient tyrosine production from acetate. Microb Cell Fact 2019; 18:57. [PMID: 30890173 PMCID: PMC6423740 DOI: 10.1186/s12934-019-1106-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 03/09/2019] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Acetate is one of promising feedstocks owing to its cheap price and great abundance. Considering that tyrosine production is gradually shifting to microbial production method, its production from acetate can be attempted to further improve the economic feasibility of its production. RESULTS Here, we engineered a previously reported strain, SCK1, for efficient production of tyrosine from acetate. Initially, the acetate uptake and gluconeogenic pathway were amplified to maximize the flux toward tyrosine. As flux distribution between glyoxylate and TCA cycles is critical for efficient precursor supplementation, the activity of the glyoxylate cycle was precisely controlled by expression of isocitrate lyase gene under different-strength promoters. Consequently, the engineered strain with optimal flux distribution produced 0.70 g/L tyrosine with 20% of the theoretical maximum yield which are 1.6-fold and 1.9-fold increased values of the parental strain. CONCLUSIONS Tyrosine production from acetate requires precise tuning of the glyoxylate cycle and we obtained substantial improvements in production titer and yield by synthetic promoters and 5' untranslated regions (UTRs). This is the first demonstration of tyrosine production from acetate. Our strategies would be widely applicable to the production of various chemicals from acetate in future.
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Affiliation(s)
- Minji Jo
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Myung Hyun Noh
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Hyun Gyu Lim
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Chae Won Kang
- Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea
| | - Dae-Kyun Im
- Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, South Korea
| | - Min-Kyu Oh
- Department of Chemical and Biological Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul, 02841, South Korea
| | - Gyoo Yeol Jung
- School of Interdisciplinary Bioscience and Bioengineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea. .,Department of Chemical Engineering, Pohang University of Science and Technology, 77 Cheongam-Ro, Nam-Gu, Pohang, Gyeongbuk, 37673, South Korea.
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14
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Tsai SF, Chang CY, Yong SM, Lim AL, Nakao Y, Chen SJ, Kuo YM. A Hydrolyzed Chicken Extract CMI-168 Enhances Learning and Memory in Middle-Aged Mice. Nutrients 2018; 11:E27. [PMID: 30583503 PMCID: PMC6356702 DOI: 10.3390/nu11010027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 12/17/2018] [Accepted: 12/19/2018] [Indexed: 12/17/2022] Open
Abstract
There has been increasing evidence that consumption of dietary supplements or specific nutrients can influence cognitive processes and emotions. A proprietary chicken meat extraction, Chicken Meat Ingredient-168 (CMI-168), has previously been shown to enhance cognitive function in humans. However, the mechanism underlying the CMI-168-induced benefits remains unclear. In this study, we investigated the effects of CMI-168 on hippocampal neuroplasticity and memory function in middle-aged (9⁻12 months old) mice. The mice in the test group (termed the "CMI-168 group") were fed dietary pellets produced by mixing CMI-168 and normal laboratory mouse chow to provide a daily CMI-168 dose of 150 mg/kg of body weight for 6 weeks. The control mice (termed the "Chow group") were fed normal laboratory mouse chow pellets. CMI-168 supplementation did not affect the body weight gain, food intake, or exploratory behavior of the mice. In the novel object recognition test, the CMI-168 group showed better hippocampus-related non-spatial memory compared to the control Chow group. However, spatial memory examined by the Morris Water Maze test was similar between the two groups. There was also no significant difference in the induction and maintenance of long-term potentiation and dendritic complexity of the hippocampal cornu ammonis region 1 (CA1) neurons, as well as the levels of neuroplasticity-related proteins in the hippocampi of the CMI-168 and Chow groups. Interestingly, we observed that CMI-168 appeared to protect the mice against stress-induced weight loss. In conclusion, dietary supplementation of CMI-168 was found to improve learning and memory in middle-aged mice, independent of structural or functional changes in the hippocampus. The resilience to stress afforded by CMI-168 warrants further investigation.
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Affiliation(s)
- Sheng-Feng Tsai
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
- College of Photonics, National Chiao Tung University, Hsinchu 30010, Taiwan.
| | - Chia-Yuan Chang
- Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan 70101, Taiwan.
| | - Shan-May Yong
- Scientific Research and Applications, BRAND'S Suntory, Singapore 048423, Singapore.
| | - Ai-Lin Lim
- Scientific Research and Applications, BRAND'S Suntory, Singapore 048423, Singapore.
| | - Yoshihiro Nakao
- Scientific Research and Applications, BRAND'S Suntory, Singapore 048423, Singapore.
| | - Shean-Jen Chen
- College of Photonics, National Chiao Tung University, Hsinchu 30010, Taiwan.
| | - Yu-Min Kuo
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
- Department of Cell Biology and Anatomy, College of Medicine, National Cheng Kung University, Tainan 70101, Taiwan.
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15
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Neuro-Cognitive Effects of Acute Tyrosine Administration on Reactive and Proactive Response Inhibition in Healthy Older Adults. eNeuro 2018; 5:eN-NWR-0035-17. [PMID: 30094335 PMCID: PMC6084775 DOI: 10.1523/eneuro.0035-17.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2017] [Revised: 03/01/2018] [Accepted: 03/24/2018] [Indexed: 01/02/2023] Open
Abstract
The aging brain is characterized by altered dopamine signaling. The amino acid tyrosine, a catecholamine precursor, is known to improve cognitive performance in young adults, especially during high environmental demands. Tyrosine administration might also affect catecholamine transmission in the aging brain, thereby improving cognitive functioning. In healthy older adults, impairments have been demonstrated in two forms of response inhibition: reactive inhibition (outright stopping) and proactive inhibition (anticipatory response slowing) under high information load. However, no study has directly compared the effects of a catecholamine precursor on reactive and load-dependent proactive inhibition. In this study we explored the effects of tyrosine on reactive and proactive response inhibition and signal in dopaminergically innervated fronto-striatal regions. Depending on age, tyrosine might lead to beneficial or detrimental neurocognitive effects. We aimed to address these hypotheses in 24 healthy older human adults (aged 61-72 years) using fMRI in a double blind, counterbalanced, placebo-controlled, within-subject design. Across the group, tyrosine did not alter reactive or proactive inhibition behaviorally but did increase fronto-parietal proactive inhibition-related activation. When taking age into account, tyrosine affected proactive inhibition both behaviorally and neurally. Specifically, increasing age was associated with a greater detrimental effect of tyrosine compared with placebo on proactive slowing. Moreover, with increasing age, tyrosine decreased fronto-striatal and parietal proactive signal, which correlated positively with tyrosine's effects on proactive slowing. Concluding, tyrosine negatively affected proactive response slowing and associated fronto-striatal activation in an age-dependent manner, highlighting the importance of catecholamines, perhaps particularly dopamine, for proactive response inhibition in older adults.
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16
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Miquel S, Champ C, Day J, Aarts E, Bahr BA, Bakker M, Bánáti D, Calabrese V, Cederholm T, Cryan J, Dye L, Farrimond JA, Korosi A, Layé S, Maudsley S, Milenkovic D, Mohajeri MH, Sijben J, Solomon A, Spencer JPE, Thuret S, Vanden Berghe W, Vauzour D, Vellas B, Wesnes K, Willatts P, Wittenberg R, Geurts L. Poor cognitive ageing: Vulnerabilities, mechanisms and the impact of nutritional interventions. Ageing Res Rev 2018; 42:40-55. [PMID: 29248758 DOI: 10.1016/j.arr.2017.12.004] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Revised: 12/08/2017] [Accepted: 12/08/2017] [Indexed: 12/21/2022]
Abstract
BACKGROUND Ageing is a highly complex process marked by a temporal cascade of events, which promote alterations in the normal functioning of an individual organism. The triggers of normal brain ageing are not well understood, even less so the factors which initiate and steer the neuronal degeneration, which underpin disorders such as dementia. A wealth of data on how nutrients and diets may support cognitive function and preserve brain health are available, yet the molecular mechanisms underlying their biological action in both normal ageing, age-related cognitive decline, and in the development of neurodegenerative disorders have not been clearly elucidated. OBJECTIVES This review aims to summarise the current state of knowledge of vulnerabilities that predispose towards dysfunctional brain ageing, highlight potential protective mechanisms, and discuss dietary interventions that may be used as therapies. A special focus of this paper is on the impact of nutrition on neuroprotection and the underlying molecular mechanisms, and this focus reflects the discussions held during the 2nd workshop 'Nutrition for the Ageing Brain: Functional Aspects and Mechanisms' in Copenhagen in June 2016. The present review is the most recent in a series produced by the Nutrition and Mental Performance Task Force under the auspice of the International Life Sciences Institute Europe (ILSI Europe). CONCLUSION Coupling studies of cognitive ageing with studies investigating the effect of nutrition and dietary interventions as strategies targeting specific mechanisms, such as neurogenesis, protein clearance, inflammation, and non-coding and microRNAs is of high value. Future research on the impact of nutrition on cognitive ageing will need to adopt a longitudinal approach and multimodal nutritional interventions will likely need to be imposed in early-life to observe significant impact in older age.
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Affiliation(s)
- Sophie Miquel
- Mars-Wrigley, 1132 W. Blackhawk Street, Chicago, IL 60642, United States
| | - Claire Champ
- Human Appetite Research Unit, School of Psychology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Jon Day
- Cerebrus Associates Limited, The White House, 2 Meadrow, Godalming, Surrey, GU7 3HN, United Kingdom
| | - Esther Aarts
- Donders Institute for Brain, Cognition, and Behaviour, Radboud University Nijmegen, Kapittelweg 29, 6525 EN Nijmegen, The Netherlands
| | - Ben A Bahr
- Biotechnology Research and Training Centre, University of North Carolina - Pembroke, United States
| | - Martijntje Bakker
- The Netherlands Organisation for Health Research and Development, Laan van Nieuw Oost-Indië 334, 2593 CE The Hague, The Netherlands
| | - Diána Bánáti
- International Life Sciences Institute, Europe (ILSI Europe), Av E. Mounier 83, Box 6, 1200 Brussels, Belgium
| | - Vittorio Calabrese
- University of Catania, Department of Biomedical and Biotechnological Sciences, Biological Tower - Via Santa Sofia, 97, Catania, Italy
| | - Tommy Cederholm
- University of Uppsala, Institutionen för folkhälso- och vårdvetenskap, Klinisk nutrition och metabolism, Uppsala Science Park, 751 85 Uppsala, Sweden
| | - John Cryan
- Anatomy & Neuroscience, University College Cork, 386 Western Gateway Building, Cork, Ireland
| | - Louise Dye
- Human Appetite Research Unit, School of Psychology, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | | | - Aniko Korosi
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Science Park 904, 1098 XH, Amsterdam, The Netherlands
| | - Sophie Layé
- Nutrition et Neurobiologie Intégrée, INRA Bordeaux University, 146 rue Léo Saignat, 33076 Bordeaux cedex, France
| | - Stuart Maudsley
- Department of Biomedical Research and VIB-UAntwerp Center for Molecular Neurology, University of Antwerp, Gebouw V, Campus Drie Eiken, Universiteitsplein 1, 2610 Antwerpen, Belgium
| | - Dragan Milenkovic
- INRA, Human Nutrition Unit, UCA, F-63003, Clermont-Ferrand, France; Department of Internal Medicine, Division of Cardiovascular Medicine, School of Medicine, University of California Davis, Davis, CA 95616, United States
| | - M Hasan Mohajeri
- DSM Nutritional Products Ltd., Wurmisweg 576, Kaiseraugst 4303, Switzerland
| | - John Sijben
- Nutricia Research, Nutricia Advanced Medical Nutrition, PO Box 80141, 3508TC, Utrecht, The Netherlands
| | - Alina Solomon
- Aging Research Center, Karolinska Institutet, Gävlegatan 16, SE-113 30 Stockholm, Sweden
| | - Jeremy P E Spencer
- Hugh Sinclair Unit of Human Nutrition and Institute for Cardiovascular and Metabolic Research, Department of Food and Nutritional Sciences, University of Reading, Whiteknights, Reading, RG6 6AP, United Kingdom
| | - Sandrine Thuret
- Institute of Psychiatry, Psychology and Neuroscience, King's College London, The Maurice Wohl Clinical Neuroscience Institute,125 Coldharbour Lane, SE5 9NU London, United Kingdom
| | - Wim Vanden Berghe
- PPES, Department Biomedical Sciences, University Antwerp, Campus Drie Eiken, Universiteitsplein 1, 2610 Antwerp, Belgium
| | - David Vauzour
- University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, United Kingdom
| | - Bruno Vellas
- Department of Geriatric Medicine, CHU Toulouse, Gerontopole, Toulouse, France
| | - Keith Wesnes
- Wesnes Cognition Limited, Little Paddock, Streatley on Thames, RG8 9RD, United Kingdom; Medical School, University of Exeter, Exeter, United Kingdom; Department of Psychology, Northumbria University, Newcastle, United Kingdom; Centre for Human Psychopharmacology, Swinburne University, Melbourne, Australia; Medicinal Plant Research Group, Newcastle University, United Kingdom
| | - Peter Willatts
- School of Psychology, University of Dundee Nethergate, Dundee, DD1 4HN, United Kingdom
| | - Raphael Wittenberg
- London School of Economics and Political Science, Personal Social Services Research Unit, London, United Kingdom
| | - Lucie Geurts
- International Life Sciences Institute, Europe (ILSI Europe), Av E. Mounier 83, Box 6, 1200 Brussels, Belgium.
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Food for thought: association between dietary tyrosine and cognitive performance in younger and older adults. PSYCHOLOGICAL RESEARCH 2017; 83:1097-1106. [PMID: 29255945 PMCID: PMC6647184 DOI: 10.1007/s00426-017-0957-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2017] [Accepted: 12/04/2017] [Indexed: 11/03/2022]
Abstract
The fact that tyrosine increases dopamine availability that, in turn, may enhance cognitive performance has led to numerous studies on healthy young participants taking tyrosine as a food supplement. As a result of this dietary intervention, participants show performance increases in working memory and executive functions. However, the potential association between habitual dietary tyrosine intake and cognitive performance has not been investigated to date. The present study aims at clarifying the association of episodic memory (EM), working memory (WM) and fluid intelligence (Gf), and tyrosine intake in younger and older adults. To this end, we acquired habitual tyrosine intake (food frequency questionnaire) from 1724 participants of the Berlin Aging Study II (1383 older adults, 341 younger adults) and modelled its relations to cognitive performance assessed in a broad battery of cognitive tasks using structural equation modeling. We observed a significant association between tyrosine intake and the latent factor capturing WM, Gf, and EM in the younger and the older sample. Due to partial strong factorial invariance between age groups for a confirmatory factor analysis on cognitive performance, we were able to compare the relationship between tyrosine and cognition between age groups and found no difference. Above and beyond previous studies on tyrosine food supplementation the present result extend this to a cross-sectional association between habitual tyrosine intake levels in daily nutrition and cognitive performance (WM, Gf, and EM). This corroborates nutritional recommendations that are thus far derived from single-dose administration studies.
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Kennedy DO, Wightman EL, Forster J, Khan J, Haskell-Ramsay CF, Jackson PA. Cognitive and Mood Effects of a Nutrient Enriched Breakfast Bar in Healthy Adults: A Randomised, Double-Blind, Placebo-Controlled, Parallel Groups Study. Nutrients 2017; 9:nu9121332. [PMID: 29215606 PMCID: PMC5748782 DOI: 10.3390/nu9121332] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 11/24/2017] [Accepted: 11/29/2017] [Indexed: 12/24/2022] Open
Abstract
Objectives: Few previous studies have assessed the effects of concomitant administration of multiple potentially psychoactive nutrients. Methods: 95 healthy adult participants consumed either a nutrient enriched breakfast bar (containing α-Linolenic acid, l-tyrosine, l-theanine, vitamins, minerals and 21.5 mg of caffeine) or an isocaloric, macronutrient matched control bar for 56 days. Cognitive function and mood were assessed pre-dose and at 40- and 160-min post-dose on the 1st and 56th day of the intervention period. Results: The results demonstrated acute effects of treatment across post-dose assessments on both assessment days in terms of alertness, and on tasks assessing attention, working and episodic memory and executive function, including cognitively demanding Serial subtraction and Rapid Visual Information Processing tasks. There were no evident chronic effects independent of the breakfast bars’ acute effects. Discussion: These results demonstrate that a nutrient enriched breakfast bar with low caffeine content can exert striking beneficial effects on acute cognitive function and alertness.
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Affiliation(s)
- David O Kennedy
- Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle-upon-Tyne NE1 8ST, UK.
| | - Emma L Wightman
- Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle-upon-Tyne NE1 8ST, UK.
| | - Joanne Forster
- Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle-upon-Tyne NE1 8ST, UK.
| | - Julie Khan
- Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle-upon-Tyne NE1 8ST, UK.
| | - Crystal F Haskell-Ramsay
- Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle-upon-Tyne NE1 8ST, UK.
| | - Philippa A Jackson
- Brain, Performance and Nutrition Research Centre, Northumbria University, Newcastle-upon-Tyne NE1 8ST, UK.
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19
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van de Rest O, Bloemendaal M, de Heus R, Aarts E. Dose-Dependent Effects of Oral Tyrosine Administration on Plasma Tyrosine Levels and Cognition in Aging. Nutrients 2017; 9:nu9121279. [PMID: 29168741 PMCID: PMC5748730 DOI: 10.3390/nu9121279] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 10/25/2017] [Accepted: 11/20/2017] [Indexed: 01/06/2023] Open
Abstract
The effects of tyrosine on plasma response and cognition in aging are unknown. We assessed the dose-dependent response to tyrosine administration in older adults in both plasma tyrosine concentrations and working memory performance. In this double blind randomized cross-over trial 17 older adults (aged 60–75 years) received a single administration of 100, 150, or 200 mg/kg body weight of tyrosine. For comparison, 17 young adults (aged 18–35 years) received a dose of 150 mg/kg body weight of tyrosine. Tyrosine plasma concentrations were determined before and 90, 120, 150, 180, 210, and 240 min after tyrosine intake. Working memory was assessed using the N-back task at 90 min after tyrosine administration. Older adults showed a dose-dependent increase in plasma tyrosine concentrations (p < 0.001), and the plasma response was higher than for young adults with the same dose (p < 0.001). Load-dependent working memory performance decreased with higher doses of tyrosine (p = 0.048), especially in older adults with greater dose-dependent plasma tyrosine responses (p = 0.035). Our results show an age-related increase in plasma tyrosine response, which was associated with a dose-dependent decline in cognitive functioning in older adults.
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Affiliation(s)
- Ondine van de Rest
- Wageningen University, Division of Human Nutrition, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
| | - Mirjam Bloemendaal
- Radboud University, Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
| | - Rianne de Heus
- Wageningen University, Division of Human Nutrition, P.O. Box 8129, 6700 EV Wageningen, The Netherlands.
- Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Department of Geriatric Medicine, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
- Radboud Alzheimer Centre, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
| | - Esther Aarts
- Radboud University, Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, P.O. Box 9101, 6500 HB Nijmegen, The Netherlands.
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Influences of glutamine administration on response selection and sequence learning: a randomized-controlled trial. Sci Rep 2017; 7:2693. [PMID: 28578427 PMCID: PMC5457419 DOI: 10.1038/s41598-017-02957-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Accepted: 04/21/2017] [Indexed: 01/08/2023] Open
Abstract
Precursors of neurotransmitters are increasingly often investigated as potential, easily-accessible methods of neuromodulation. However, the amino-acid glutamine, precursor to the brain’s main excitatory and inhibitory neurotransmitters glutamate and GABA, remains notably little investigated. The current double-blind, randomized, placebo-controlled study provides first evidence 2.0 g glutamine administration in healthy adults affects response selection but not motor sequence learning in a serial reaction time task. Specifically, glutamine increased response selection errors when the current target response required a different hand than the directly preceding target response, which might indicate enhanced cortical excitability via a presumed increase in glutamate levels. These results suggest glutamine can alter cortical excitability but, despite the critical roles of glutamate and GABA in motor learning, at its current dose glutamine does not affect sequence learning.
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Jongkees BJ, Sellaro R, Beste C, Nitsche MA, Kühn S, Colzato LS. l -Tyrosine administration modulates the effect of transcranial direct current stimulation on working memory in healthy humans. Cortex 2017; 90:103-114. [DOI: 10.1016/j.cortex.2017.02.014] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 12/01/2016] [Accepted: 02/18/2017] [Indexed: 10/20/2022]
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Shearer J, Graham TE, Skinner TL. Nutra-ergonomics: influence of nutrition on physical employment standards and the health of workers. Appl Physiol Nutr Metab 2017; 41:S165-74. [PMID: 27277565 DOI: 10.1139/apnm-2015-0531] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The importance of ergonomics across several scientific domains, including biomechanics, psychology, sociology, and physiology, have been extensively explored. However, the role of other factors that may influence the health and productivity of workers, such as nutrition, is generally overlooked. Nutra-ergonomics describes the interface between workers, their work environment, and performance in relation to their nutritional status. It considers nutrition to be an integral part of a safe and productive workplace that encompasses physical and mental health as well as the long-term wellbeing of workers. This review explores the knowledge, awareness, and common practices of nutrition, hydration, stimulants, and fortified product use employed prior to physical employment standards testing and within the workplace. The influence of these nutra-ergonomic strategies on physical employment standards, worker safety, and performance will be examined. Further, the roles, responsibilities, and implications for the applicant, worker, and the employer will be discussed within the context of nutra-ergonomics, with reference to the provision and sustainability of an environment conducive to optimize worker health and wellbeing. Beyond physical employment standards, workplace productivity, and performance, the influence of extended or chronic desynchronization (irregular or shift work) in the work schedule on metabolism and long-term health, including risk of developing chronic and complex diseases, is discussed. Finally, practical nutra-ergonomic strategies and recommendations for the applicant, worker, and employer alike will be provided to enhance the short- and long-term safety, performance, health, and wellbeing of workers.
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Affiliation(s)
- Jane Shearer
- a Department of Biochemistry and Molecular Biology, Cumming School of Medicine. Faculty of Kinesiology, University of Calgary, Calgary, AB T2N 1N4, Canada
| | - Terry E Graham
- b Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON N1G 2W1, Canada
| | - Tina L Skinner
- c Centre for Research on Exercise, Physical Activity and Health, School of Human Movement and Nutrition Sciences, Faculty of Health and Behavioural Sciences, The University of Queensland, Brisbane, Queensland QLD 4072, Australia
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Colzato LS, Steenbergen L, Sellaro R, Stock AK, Arning L, Beste C. Effects of l-Tyrosine on working memory and inhibitory control are determined by DRD2 genotypes: A randomized controlled trial. Cortex 2016; 82:217-224. [PMID: 27403851 DOI: 10.1016/j.cortex.2016.06.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2016] [Revised: 05/16/2016] [Accepted: 06/09/2016] [Indexed: 11/19/2022]
Abstract
l-Tyrosine (TYR), the precursor of dopamine (DA), has been shown to enhance facets of cognitive control in situations with high cognitive demands. However some previous outcomes were mixed: some studies reported significant improvements, while other did not. Given that TYR increases DA level in the brain, we investigated, in a double-blind, randomized, placebo-controlled design, whether the C957T genotypes of a functional synonymous polymorphism in the human dopamine D2 receptor (DRD2) gene (rs6277) contribute to individual differences in the reactivity to TYR administration and whether this factor predicts the magnitude of TYR-induced performance differences on inhibiting behavioral responses in a stop-signal task and working memory (WM) updating in a N-back task. Our findings show that T/T homozygotes (i.e., individuals potentially associated with lower striatal DA level) showed larger beneficial effects of TYR supplementation than C/C homozygotes (i.e., individuals potentially associated with higher striatal DA level), suggesting that genetically determined differences in DA function may explain inter-individual differences in response to TYR supplementation. These findings reinforce the idea that genetic predisposition modulates the effect of TYR in its role as cognitive enhancer.
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Affiliation(s)
- Lorenza S Colzato
- Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
| | - Laura Steenbergen
- Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands
| | - Roberta Sellaro
- Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands
| | - Ann-Kathrin Stock
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine of the TU Dresden, Dresden, Germany
| | - Larissa Arning
- Department of Human Genetics, Medical Faculty, Ruhr-University Bochum, Bochum, Germany
| | - Christian Beste
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine of the TU Dresden, Dresden, Germany; Experimental Neurobiology, National Institute of Mental Healthy, Klecany, Czech Republic
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Effects of amino acid derivatives on physical, mental, and physiological activities. Crit Rev Food Sci Nutr 2016; 55:1793-807. [PMID: 24279396 DOI: 10.1080/10408398.2012.708368] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Nutritional ergogenic aids have been in use for a long time to enhance exercise and sports performance. Dietary components that exhibit ergogenic activity are numerous and their consumption is common and popular among athletes. They often come under scrutiny by legal authorities for their claimed benefits and safety concerns. Amino acid derivatives are propagated as being effective aids to enhance physical and mental performance in many ways, even though studies have pointed out that individuals who are deficient are more likely to benefit from dietary supplementation of amino acid derivatives than normal humans. In this review, some of the most common and widely used amino acids derivatives in sports and athletics namely creatine, tyrosine, carnitine, HMB, and taurine have been discussed for their effects on exercise performance, mental activity as well as body strength and composition. Creatine, carnitine, HMB, and taurine are reported to delay the onset of fatigue, improve exercise performance, and body strength. HMB helps in increasing fat-free mass and reduce exercise induced muscle injury. Taurine has been found to reduce oxidative stress during exercise and also act as an antihypertensive agent. Although, studies have not been able to find any favorable effect of tyrosine administration on exercise performance, it has been proved to be very effective in fighting stress, improving mood and cognitive performance particularly in sleep-deprived subjects. While available data from published studies and findings are equivocal about the efficacy of creatine, tyrosine, and HMB, more comprehensive researches on carnitine and taurine are necessary to provide evidence for the theoretical basis of their ergogenic role in nutritional modification and supplementation.
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Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands--A review. J Psychiatr Res 2015; 70:50-7. [PMID: 26424423 DOI: 10.1016/j.jpsychires.2015.08.014] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Revised: 07/28/2015] [Accepted: 08/24/2015] [Indexed: 10/23/2022]
Abstract
Consuming the amino-acid tyrosine (TYR), the precursor of dopamine (DA) and norepinephrine (NE), may counteract decrements in neurotransmitter function and cognitive performance. However, reports on the effectiveness of TYR supplementation vary considerably, with some studies finding beneficial effects, whereas others do not. Here we review the available cognitive/behavioral studies on TYR, to elucidate whether and when TYR supplementation can be beneficial for performance. The potential of using TYR supplementation to treat clinical disorders seems limited and its benefits are likely determined by the presence and extent of impaired neurotransmitter function and synthesis. Likewise, the potential of TYR supplementation for enhancing physical exercise seems minimal as well, perhaps because the link between physical exercise and catecholamine function is mediated by many other factors. In contrast, TYR does seem to effectively enhance cognitive performance, particularly in short-term stressful and/or cognitively demanding situations. We conclude that TYR is an effective enhancer of cognition, but only when neurotransmitter function is intact and DA and/or NE is temporarily depleted.
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Behavioral and cognitive effects of tyrosine intake in healthy human adults. Pharmacol Biochem Behav 2015; 133:1-6. [DOI: 10.1016/j.pbb.2015.03.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/14/2014] [Revised: 02/20/2015] [Accepted: 03/12/2015] [Indexed: 11/21/2022]
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Childs E. Influence of energy drink ingredients on mood and cognitive performance. Nutr Rev 2015; 72 Suppl 1:48-59. [PMID: 25293543 DOI: 10.1111/nure.12148] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Sales of energy products have grown enormously in recent years. Manufacturers claim that the products, in the form of drinks, shots, supplements, and gels, enhance physical and cognitive performance, while users believe the products promote concentration, alertness, and fun. Most of these products contain caffeine, a mild psychostimulant, as their foremost active ingredient. However, they also contain additional ingredients, e.g., carbohydrates, amino acids, herbal extracts, vitamins, and minerals, often in unspecified amounts and labeled as an "energy blend." It is not clear whether these additional ingredients provide any physical or cognitive enhancement beyond that provided by caffeine alone. This article reviews the available empirical data on the interactive effects of these ingredients and caffeine on sleep and cognitive performance and suggests objectives for future study.
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Affiliation(s)
- Emma Childs
- The University of Chicago, Department of Psychiatry and Behavioral Neuroscience, Chicago, Illinois, USA
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Steenbergen L, Sellaro R, Hommel B, Colzato LS. Tyrosine promotes cognitive flexibility: evidence from proactive vs. reactive control during task switching performance. Neuropsychologia 2015; 69:50-5. [PMID: 25598314 DOI: 10.1016/j.neuropsychologia.2015.01.022] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Revised: 01/12/2015] [Accepted: 01/15/2015] [Indexed: 11/25/2022]
Abstract
Tyrosine (TYR), an amino acid found in various foods, has been shown to increase dopamine (DA) levels in the brain. Recent studies have provided evidence that TYR supplementation can improve facets of cognitive control in situations with high cognitive demands. Here we investigated whether TYR promotes cognitive flexibility, a cognitive-control function that is assumed to be modulated by DA. We tested the effect of TYR on proactive vs. reactive control during task switching performance, which provides a relatively well-established diagnostic of cognitive flexibility. In a double-blind, randomized, placebo-controlled design, 22 healthy adults performed in a task-switching paradigm. Compared to a neutral placebo, TYR promoted cognitive flexibility (i.e. reduced switching costs). This finding supports the idea that TYR can facilitate cognitive flexibility by repleting cognitive resources.
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Affiliation(s)
- Laura Steenbergen
- Institute for Psychological Research, Leiden University, The Netherlands; Leiden Institute for Brain and Cognition, Leiden University, Leiden, 2333 AK Leiden, The Netherlands.
| | - Roberta Sellaro
- Institute for Psychological Research, Leiden University, The Netherlands; Leiden Institute for Brain and Cognition, Leiden University, Leiden, 2333 AK Leiden, The Netherlands
| | - Bernhard Hommel
- Institute for Psychological Research, Leiden University, The Netherlands; Leiden Institute for Brain and Cognition, Leiden University, Leiden, 2333 AK Leiden, The Netherlands
| | - Lorenza S Colzato
- Institute for Psychological Research, Leiden University, The Netherlands; Leiden Institute for Brain and Cognition, Leiden University, Leiden, 2333 AK Leiden, The Netherlands
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Lieberman HR, Thompson LA, Caruso CM, Niro PJ, Mahoney CR, McClung JP, Caron GR. The catecholamine neurotransmitter precursor tyrosine increases anger during exposure to severe psychological stress. Psychopharmacology (Berl) 2015; 232:943-51. [PMID: 25220844 PMCID: PMC4325185 DOI: 10.1007/s00213-014-3727-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2013] [Accepted: 08/22/2014] [Indexed: 12/01/2022]
Abstract
RATIONALE Acute stress produces behavioral and physiological changes modulated by central catecholamines (CA). Stress increases CA activity, and depletion of CA stores reduces responses to stress. Increasing CA activity by administration of the dietary amino acid CA precursor tyrosine may increase responsiveness to stress. This study determined whether tyrosine enhances the ability of humans to respond to severe stress. METHODS Severe psychological stress was generated during training at Survival, Evasion, Resistance, and Escape (SERE) School. The acute stressor consisted of two mock interrogations conducted during several days of simulated captivity. Seventy-eight healthy male and female military personnel participated in this double-blind, between-subjects study, in which they received either tyrosine (300 mg/kg, N = 36) or placebo (N = 36). Tyrosine (or placebo) was administered in food bars in two doses of 150 mg/kg each approximately 60 min before each mock interrogation. Mood (Profile of Mood States), saliva cortisol, and heart rate (HR) were assessed prior to stress exposure during a week of academic training preceding mock captivity and immediately following the mock interrogations. RESULTS The severe stress produced robust effects on mood (i.e., increased tension, depression, anger, fatigue, vigor, and confusion; p < .001), cortisol, and HR (p < .001). Tyrosine increased anger (p = .002, ANOVA treatment condition by test session interaction) during stress but had no other effects. CONCLUSION Tyrosine did not alter most subjective or physiological responses to severe acute stress, but it increased ratings of anger. The modest increase in anger may be an adaptive emotional response in stressful environments.
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Affiliation(s)
- Harris R. Lieberman
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Kansas Street, Natick, MA 01760 USA
| | - Lauren A. Thompson
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Kansas Street, Natick, MA 01760 USA
| | - Christina M. Caruso
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Kansas Street, Natick, MA 01760 USA
| | - Philip J. Niro
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Kansas Street, Natick, MA 01760 USA
| | - Caroline R. Mahoney
- Cognitive Sciences, US Army Natick Soldier Research, Development, and Engineering Center, Kansas Street, Natick, MA 01760 USA
| | - James P. McClung
- Military Nutrition Division, US Army Research Institute of Environmental Medicine, Kansas Street, Natick, MA 01760 USA
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Baker LB, Nuccio RP, Jeukendrup AE. Acute effects of dietary constituents on motor skill and cognitive performance in athletes. Nutr Rev 2014; 72:790-802. [PMID: 25400063 DOI: 10.1111/nure.12157] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Performance in many sports is at least partially dependent on motor control, coordination, decision-making, and other cognitive tasks. This review summarizes available evidence about the ingestion of selected nutrients or isolated compounds (dietary constituents) and potential acute effects on motor skill and/or cognitive performance in athletes. Dietary constituents discussed include branched-chain amino acids, caffeine, carbohydrate, cocoa flavanols, Gingko biloba, ginseng, guarana, Rhodiola rosea, sage, L-theanine, theobromine, and tyrosine. Although this is not an exhaustive list, these are perhaps the most researched dietary constituents. Caffeine and carbohydrate have the greatest number of published reports supporting their ability to enhance acute motor skill and cognitive performance in athletes. At this time, there is insufficient published evidence to substantiate the use of any other dietary constituents to benefit sports-related motor skill or cognitive performance. The optimal dose and timing of caffeine and carbohydrate intake promoting enhanced motor skill and cognitive performance remain to be identified. Valid, reliable, and sensitive batteries of motor skills and cognitive tests should be developed for use in future efficacy studies.
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Affiliation(s)
- Lindsay B Baker
- Gatorade Sports Science Institute, Barrington, Illinois, USA
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Jongkees BJ, Hommel B, Colzato LS. People are different: tyrosine's modulating effect on cognitive control in healthy humans may depend on individual differences related to dopamine function. Front Psychol 2014; 5:1101. [PMID: 25339925 PMCID: PMC4186281 DOI: 10.3389/fpsyg.2014.01101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 09/11/2014] [Indexed: 01/22/2023] Open
Affiliation(s)
- Bryant J Jongkees
- Institute of Psychological Research and Leiden Institute for Brain and Cognition, Leiden University Leiden, Netherlands
| | - Bernhard Hommel
- Institute of Psychological Research and Leiden Institute for Brain and Cognition, Leiden University Leiden, Netherlands
| | - Lorenza S Colzato
- Institute of Psychological Research and Leiden Institute for Brain and Cognition, Leiden University Leiden, Netherlands
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Food for creativity: tyrosine promotes deep thinking. PSYCHOLOGICAL RESEARCH 2014; 79:709-14. [DOI: 10.1007/s00426-014-0610-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Accepted: 09/05/2014] [Indexed: 10/24/2022]
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Colzato LS, Jongkees BJ, Sellaro R, van den Wildenberg WPM, Hommel B. Eating to stop: tyrosine supplementation enhances inhibitory control but not response execution. Neuropsychologia 2014; 62:398-402. [PMID: 24433977 DOI: 10.1016/j.neuropsychologia.2013.12.027] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2013] [Revised: 12/11/2013] [Accepted: 12/31/2013] [Indexed: 10/25/2022]
Abstract
Animal studies and research in humans have shown that the supplementation of tyrosine, or tyrosine-containing diets, increase the plasma tyrosine and enhance brain dopamine (DA). However, the strategy of administering tyrosine (and the role of DA therein) to enhance cognition is unclear and heavily debated. We studied, in a healthy population, whether tyrosine supplementation improves stopping overt responses, a core cognitive-control function. In a double-blind, placebo-controlled, within-subject design, one hour following the administration of tyrosine (corresponding to the beginning of the 1h-peak of the plasma concentration) or placebo, participants performed a stop-signal task-which taps into response inhibition and response execution speed. Participants in the Tyrosine condition were more efficient in inhibiting unwanted action tendencies but not in reacting to go signals. This is the first demonstration that the supplementation of tyrosine selectively targets, and reliably improves the ability to stop overt responses.
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Affiliation(s)
- Lorenza S Colzato
- Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands.
| | - Bryant J Jongkees
- Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands
| | - Roberta Sellaro
- Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands
| | - Wery P M van den Wildenberg
- University of Amsterdam, Amsterdam Center for the Study of Adaptive Control in Brain and Behaviour (Acacia), Psychology Department, Amsterdam, The Netherlands
| | - Bernhard Hommel
- Leiden University, Cognitive Psychology Unit & Leiden Institute for Brain and Cognition, Leiden, The Netherlands
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Colzato LS, Jongkees BJ, Sellaro R, Hommel B. Working memory reloaded: tyrosine repletes updating in the N-back task. Front Behav Neurosci 2013; 7:200. [PMID: 24379768 PMCID: PMC3863934 DOI: 10.3389/fnbeh.2013.00200] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Accepted: 11/25/2013] [Indexed: 01/20/2023] Open
Abstract
In this study we tested the idea that the food supplement l-Tyrosine (TYR) repletes resources required for cognitive-control operations. We investigated whether the “updating” (and monitoring) of working memory (WM) representations, a key cognitive-control function, can be promoted by administering TYR, the biochemical precursor of dopamine. Participants performed an N-back task where we compared the WM-demanding 2-back condition with the WM-undemanding 1-back condition. As expected, TYR promoted performance in the more demanding (2-back) but not in the easier (1-back) condition, suggesting that TYR selectively targets cognitive-control operations. This result suggests that TYR can replete cognitive resources when more control is needed and, more generally, that food can act as a cognitive enhancer.
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Affiliation(s)
- Lorenza S Colzato
- Institute for Psychological Research, Leiden Institute for Brain and Cognition, Leiden University , Leiden , Netherlands
| | - Bryant J Jongkees
- Institute for Psychological Research, Leiden Institute for Brain and Cognition, Leiden University , Leiden , Netherlands
| | - Roberta Sellaro
- Institute for Psychological Research, Leiden Institute for Brain and Cognition, Leiden University , Leiden , Netherlands
| | - Bernhard Hommel
- Institute for Psychological Research, Leiden Institute for Brain and Cognition, Leiden University , Leiden , Netherlands
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van de Rest O, van der Zwaluw NL, de Groot LCPGM. Literature review on the role of dietary protein and amino acids in cognitive functioning and cognitive decline. Amino Acids 2013; 45:1035-45. [DOI: 10.1007/s00726-013-1583-0] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 08/15/2013] [Indexed: 11/28/2022]
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Scientific Opinion on the substantiation of health claims related to L-tyrosine and contribution to normal synthesis of catecholamines (ID 1928), increased attention (ID 440, 1672, 1930), and contribution to normal muscle function (ID 1929) pursuant to Ar. EFSA J 2011. [DOI: 10.2903/j.efsa.2011.2270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Mache S, Kusma B, Vitzthum K, Nienhaus A, Klapp BF, Groneberg DA. Analysis and evaluation of geriatricians' working routines in German hospitals. Geriatr Gerontol Int 2011; 12:108-15. [DOI: 10.1111/j.1447-0594.2011.00714.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Mahoney CR, Castellani J, Kramer FM, Young A, Lieberman HR. Tyrosine supplementation mitigates working memory decrements during cold exposure. Physiol Behav 2007; 92:575-82. [PMID: 17585971 DOI: 10.1016/j.physbeh.2007.05.003] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Revised: 04/16/2007] [Accepted: 05/02/2007] [Indexed: 11/16/2022]
Abstract
In rats, dietary supplementation with the amino acid tyrosine (TYR) prevents depletion of central catecholamines observed during acute environmental stress. Concomitant changes in the animals' behavioral responses to stress suggest that TYR might have similar effects on central catecholamines and cognition in humans exposed to environmental stress. This study aimed to determine if severe cold exposure impairs human cognition and if dietary supplementation with TYR would ameliorate such deficits. Volunteers (N=19) completed three test sessions on different days (35 degrees C control/placebo, approximately 10 degrees C/placebo, approximately 10 degrees C/TYR) using a double-blind, within subjects design. During each session, volunteers completed two 90-minute water immersions and consumed a food bar (150 mg/kg TYR or placebo) before each immersion (total TYR 300 mg/kg). Cognitive performance, mood, and salivary cortisol were assessed. Cortisol was elevated in the cold (p<.01). Volunteers made fewer correct responses on a Match-to-Sample memory measure (p<.05) and reaction time (RT) and errors increased on a choice RT test (p<.01) in the cold. Self-reported tension (p<.01), depression (p<.05) and confusion (p<.01) also increased in the cold. When volunteers consumed TYR, correct responses increased on a Match-to-Sample memory measure (p<.05) and study time for the sample was shorter (p<.05), indicative of more rapid and accurate information processing. Finally, RT on the memory measure revealed a similar pattern across immersions for TYR and thermoneutral conditions, but not cold/placebo (p<.05). This study demonstrates cold exposure degrades cognitive performance and supplementation with TYR alleviates working memory decrements.
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Affiliation(s)
- Caroline R Mahoney
- US Army Soldier Research, Development and Engineering Center, Kansas Street, Natick, MA 01760-5020, USA.
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Aquilani R, Verri M, Iadarola P, Arcidiaco P, Boschi F, Dossena M, Sessarego P, Scocchi M, Arrigoni N, Pastoris O. Plasma precursors of brain catecholaminergic and serotonergic neurotransmitters in rehabilitation patients with ischemic stroke11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated. Arch Phys Med Rehabil 2004; 85:779-84. [PMID: 15129403 DOI: 10.1016/j.apmr.2003.06.030] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE To determine levels of plasma amino acid tyrosine and tryptophan, precursors of brain catecholamine and serotonin neurotransmitters, respectively, in rehabilitative patients with ischemic stroke. DESIGN Controlled, pre-post analysis, consecutive sample. SETTING Rehabilitation center. PARTICIPANTS Twenty men with ischemic stroke (age, 68+/-11.3y) consecutively admitted into rehabilitation 15+/-10 days (range, 7-28d) after an acute cerebrovascular insult; 15 healthy sedentary subjects (controls 1); and 13 healthy hypoactive individuals who had recently had knee arthroplasty (controls 2). Both control groups were matched to stroke subjects for age, gender, and body weight. INTERVENTIONS At 8:00 am, after overnight fasting, venous blood samples were drawn from patients to determine plasma tyrosine and tryptophan levels. A nutritional evaluation, including nitrogen balance, was made. The same procedures were repeated after 45 days of rehabilitation. Amino acid data were compared with those obtained from the controls. MAIN OUTCOME MEASURE Plasma concentrations of amino acids. RESULTS Patients with ischemic stroke, on admission, had lower plasma tyrosine concentration than did both controls 1 (P<.0005) and controls 2 (P<.001), but a similar tryptophan level. The plasma content of tyrosine was similar between the 2 control groups. After 45 days of rehabilitation, the stroke patients' tyrosine and tryptophan levels remained virtually unchanged, as did nutritional parameters. Nutritional intakes were adequate to meet body needs but insufficient to correct plasma tyrosine. CONCLUSIONS Patients experiencing a recent stroke may have low plasma tyrosine levels and, therefore, reduced brain catecholamine formation. It is possible that an imbalance of brain neurotransmitters may occur.
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Affiliation(s)
- Roberto Aquilani
- Servizio di Fisiopatologia Metabolico-Nutrizionale e Nutrizione Clinica, Fondazione S Maugeri, Istituto Scientifico di Montescano, Montescano, Pavia, Italia
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Aquilani R, Iadarola P, Boschi F, Pistarini C, Arcidiaco P, Contardi A. Reduced plasma levels of tyrosine, precursor of brain catecholamines, and of essential amino acids in patients with severe traumatic brain injury after rehabilitation11No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors(s) or upon any organization with which the author(s) is/are associated. Arch Phys Med Rehabil 2003; 84:1258-65. [PMID: 13680559 DOI: 10.1016/s0003-9993(03)00148-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE To investigate whether levels of plasma tyrosine and tryptophan, precursors of brain catecholamine and serotonin neurotransmitters, respectively, and other essential amino acids (EAA) may return to normal in patients with severe traumatic brain injury (TBI) after 2 months in a hospital rehabilitation center. DESIGN Peripheral plasma concentrations of tyrosine, tryptophan, and other EAAs in subjects with severe TBI, both at admission (44+/-11d postinjury) and at discharge from the center (110+/-15d after acute event) were compared with concentrations in control subjects. SETTING Tertiary care rehabilitation setting in Italy. PARTICIPANTS Ten men (26.6+/-12.6y) with TBI and 6 healthy subjects (controls) matched for age, sex, voluntary loss of body weight, and sedentary lifestyle. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Concentrations of brain neurotransmitter precursor amino acids and of EAA. RESULTS On admission, patients had lower plasma tyrosine, leucine, valine, methionine, and phenylalanine concentrations than did control subjects. The plasma concentrations of tryptophan were similar in the 2 groups. These amino acid abnormalities were still present at discharge. CONCLUSION The levels of plasma tyrosine and many EAA in patients with TBI did not recover by discharge (110+/-15d) from rehabilitation. Plasma tryptophan concentrations were similar in patients and controls.
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Affiliation(s)
- Roberto Aquilani
- Servizio di Fisiopatologia Metabolico-Nutrizionale e Nutrizione Clinica, Fondazione S. Maugeri, Istituto Scientifico di Montescano, Pavia, Italy
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Abstract
UNLABELLED Our knowledge about the influence of nutritional supplements on human cognition, especially in the elderly, rests largely on animal behavioural research and neurochemical experiments in vitro, while only a few epidemiological studies and even fewer controlled experiments in humans are reported. This is an inherent problem, due partly to the difficulty of conducting controlled nutritional experiments in humans, but may also partly be due to the gap between the research disciplines of nutritional and neurobehavioral experimental science. LEARNING OBJECTIVES The aim of this paper is to discuss some new findings in this line of research, and to stress the importance of the need to start bridging the gap between disciplines by identifying possible human experimental models of altered cognitive function, which can elucidate the specific mechanisms of action through which nutritional supplements may enhance cognitive performance in humans in vivo. These experimental models are important because the research in this field is mostly based on epidemiological studies, which describe associations between nutrients and cognitive functions. Contrary to epidemiological studies, experimental models mimic associations between nutrients and cognition by manipulating their presumed mechanisms of action and can eventually explain the causal nature of found associations.
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Affiliation(s)
- B L Jorissen
- Experimental Psychopharmacology Unit, Brain & Behaviour Institute, Universiteit Maastricht, Maastricht, The Netherlands
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Hao S, Avraham Y, Bonne O, Berry EM. Separation-induced body weight loss, impairment in alternation behavior, and autonomic tone: effects of tyrosine. Pharmacol Biochem Behav 2001; 68:273-81. [PMID: 11267632 DOI: 10.1016/s0091-3057(00)00448-2] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
We have investigated the effects of tyrosine on alternation behavior and hippocampal adrenergic and cholinergic tone in a model of self-induced weight loss caused by separation stress. Separation decreased body weight in mice (P < .001) and spontaneous alternations in the T-maze (P < .001). This impairment was associated with depletion of both norepinephrine (NE, P < .001) and dopamine (P < .01) while increasing MHPG (P < .05) and the ratio of MHPG/NE (P < .05). Increasing tyrosine availability restored performance to control levels (P < .001) and repleted dopamine (P < .05) and presumably also NE (indicated by increases in both MHPG, P < .001, and MHPG/NE, P < .05). Stress increased adrenergic alpha(2)-receptor density (P < .001) without changing its K(d) and the B(max) and K(d) of beta-receptors, suggesting that it decreased NE transmission through action on alpha(2)-receptors. The balance between beta- and alpha(2)-receptors appeared to be related to alternation behavior as shown by the decrease (P < .01) and increase (P < .05) in their ratios induced by stress and tyrosine, respectively. With regard to cholinergic tone, separation stress increased M1 receptor density (P < .05) and its mRNA signal (P < .001). Tyrosine further increased M1 receptor density of stressed mice (P < .05). Tyrosine might be a potential therapy for cognitive and mood problems associated with the maintenance of a reduced body weight in the treatment of obesity and in the extreme case of anorexia nervosa.
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MESH Headings
- Animals
- Behavior, Animal/drug effects
- Behavior, Animal/physiology
- Carrier Proteins/drug effects
- Carrier Proteins/metabolism
- Dopamine/metabolism
- Female
- Hippocampus/drug effects
- Hippocampus/metabolism
- Methoxyhydroxyphenylglycol/metabolism
- Mice
- Norepinephrine/metabolism
- Receptor, Muscarinic M1
- Receptors, Adrenergic, alpha-2/drug effects
- Receptors, Adrenergic, alpha-2/metabolism
- Receptors, Adrenergic, beta/drug effects
- Receptors, Adrenergic, beta/metabolism
- Receptors, Muscarinic/drug effects
- Receptors, Muscarinic/metabolism
- Stress, Psychological/metabolism
- Stress, Psychological/psychology
- Tyrosine/pharmacology
- Weight Loss/drug effects
- Weight Loss/physiology
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Affiliation(s)
- S Hao
- Department of Human Nutrition and Metabolism, Hadassah Medical School, Hebrew University, Jerusalem, Israel
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Abstract
There is currently intense interest in the effects of macronutrients on psychological states, mental performance, and well-being. A strong theoretical perspective has guided work on carbohydrates and their relation to brain serotoninergic function with concomitant effects on performance. The clearest and most reliable effects have been observed for the beneficial action of glucose on cognitive performance, supported by investigations of hypoglycemia, which is associated with general impairment of cognitive performance. The effects of complex carbohydrates are less distinct and change with time of day; e.g., carbohydrate at breakfast tends to improve morning performance. However, these studies are rarely decisive. Far fewer experiments have been performed on protein and fat, and it is difficult to draw any firm conclusions. Macronutrients are seldom given alone, proportions of protein and fat differ greatly between studies, and comparisons are frequently performed with no food at all. Food intake may mitigate the effects of low doses but not of high doses of alcohol on performance. Effects of macronutrients on cognitive performance may be dependent on their effects on glucose metabolism, metabolic activation, or serotonin. Other factors that modify effects include time of day, circadian rhythms, type of task, habitual diet, and vulnerability of the population.
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Affiliation(s)
- L Dye
- Biopsychology Group, School of Psychology, University of Leeds, Leeds, UK.
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