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1.
Nutr Rev ; 2023 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-37695299

RESUMO

CONTEXT: Sleep disturbances are a core symptom of menopause, which refers to the permanent cessation of menstrual periods. Nutritional interventions may alleviate menopause-related sleep disturbances, as studies have shown that certain interventions (eg, tart cherry juice, or tryptophan-rich foods) can improve relevant aspects of sleep. OBJECTIVE: The aim of this systematic review was to examine the effect of nutritional interventions for menopause-related sleep disturbances, in order to inform the subsequent development of specific interventional trials and assess their potential as a treatment for menopause-related sleep disturbances. DATA SOURCES: Published studies in English were located by searching PubMed and PsycArticles databases (until September 15, 2022). DATA EXTRACTION: Following full-text review, a final total of 59 articles were included. The search protocol was performed in accordance with PRISMA guidelines. DATA ANALYSIS: A total of 37 studies reported that a nutritional intervention improved some aspect of sleep, and 22 studies observed no benefit. Most (n = 24) studies recruited postmenopausal women, 18 recruited menopausal women, 3 recruited perimenopausal women, and 14 recruited women from multiple groups. The majority of the studies were of low methodological quality. Due to the heterogeneity of the studies, a narrative synthesis without meta-analysis is reported. CONCLUSION: Despite the large heterogeneity in the studies and choice of intervention, the majority of the identified studies reported that a nutritional intervention did benefit sleep, and that it is mainly subjective sleep that is improved. More high-quality, adequately powered, randomized controlled trials of the identified nutritional interventions are necessary. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42021262367.

2.
Nutrients ; 14(11)2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35684062

RESUMO

The incidence of several diet and lifestyle-related diseases, previously seen only in adults, is increasing in prevalence in young people. The Black population, and particularly Black males, are at high risk of developing lifestyle-related diseases. Adolescence and young adulthood are considered a transitional period with increasing independence and responsibility, along with the development of lifelong lifestyle habits. This systematic review aimed to establish which methods and approaches to nutritional education interventions are the most effective in improving the nutritional/dietary intake in healthy young Black males. Eligibility criteria were designed using PICOS and included controlled trials of nutrition education interventions designed to improve dietary intake in healthy young Black or mixed-race males aged 14-21 years old. Medline, Cinahl and Scopus were searched in April 2021, resulting in 20,375 records being screened, and subsequently 72 full-text articles were reviewed. Risk of bias was assessed using the ROBINS-I tool. One study met the eligibility criteria. Results are presented in a narrative format as meta-analysis was not possible. This systematic review revealed a lack of evidence on the effectiveness of nutritional education interventions in this high-risk population. Limitations are noted and recommendations have been made.


Assuntos
Ingestão de Alimentos , Terapia Nutricional , Adolescente , Adulto , Dieta , Educação em Saúde , Humanos , Estilo de Vida , Masculino , Terapia Nutricional/métodos , Adulto Jovem
3.
Nutr Neurosci ; 25(11): 2335-2343, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34380382

RESUMO

Background: Polyphenols from coffee berry (chlorogenic acid) and apple (flavanol) have been shown to improve mood and increase cerebral blood flow in healthy humans. These effects may underpin the cognitive effects of polyphenols seen previously.Objective: The aim of the present paper was to extend previous research by investigating the effects of coffee berry at high and low doses when combined with apple extract on cognitive performance and mood.Design: This randomised, double-blind, placebo controlled, crossover trial included 46 healthy males and females,18-49 years of age (mean age 23 years),consuming: 1100 mg coffee berry extract, 1100 mg coffee berry extract plus 275 mg apple extract, 100 mg coffee berry extract plus 275 mg apple extract or placebo on 4 separate occasions, completing cognitive and mood assessments pre-dose and then again at 1-, 3- and 6 hrs post-dose.Results: Analysis revealed a consistent pattern of alerting effects following 1100 mg coffee berry extract. Limited effects on cognitive function were observed. Specifically, faster peg and ball performance (executive function) was observed following 1100 mg coffee berry plus apple extract and accuracy on the Rapid Visual Information Processing (RVIP) task increased on the third of four repetitions following 1100 mg coffee berry alone. Interestingly, more false alarms on RVIP were observed following the same intervention.Conclusions: In line with previous findings, 1100 mg coffee berry engendered increased arousal. The absence of effects on mood when an apple extract was added, and the potential for the low dose of caffeine within the coffee berry to act synergistically with polyphenols, raise interesting future avenues of research.Abbreviations: Cognitive demand battery (CDB), Profile Of Mood States (POMS), Visual Analogue Scale (VAS), Rapid Visual Information Processing (RVIP).


Assuntos
Coffea , Malus , Masculino , Feminino , Humanos , Adulto Jovem , Adulto , Estudos Cross-Over , Afeto , Cognição , Método Duplo-Cego , Extratos Vegetais/farmacologia
4.
J Phys Act Health ; 18(1): 2-7, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33260144

RESUMO

BACKGROUND: Physical activity provides a number of physical and psychological benefits. Multimodal proprioceptive exercise represents a useful balance-based exercise with the potential to reduce falls in older adults. Previous research has also indicated cognitive benefits following multimodal proprioceptive exercise in young and older adults. This study aimed to assess cognition and mood following 2 types of physical activity (multimodal proprioception vs yoga) compared with control (classroom-based) in healthy older adults. METHOD: Nineteen older adults (Mage = 65, sex = 9 males) participated in this randomized controlled crossover trial. Participants completed a 20-minute multimodal proprioceptive exercise class, 20-minute yoga session, and 20-minute classroom-based control. Numeric working memory and mood were assessed before and immediately following each of the interventions. RESULTS: The multimodal proprioceptive intervention significantly reduced numeric working memory reaction time versus the yoga (P = .043) and control (P = .023) group. There were no differences found for accuracy or mood. CONCLUSIONS: These results indicate that multimodal proprioceptive exercise is worthy of further investigation as an alternative mode of exercise alongside the more traditional aerobic and strength-based exercise for healthy older adults.


Assuntos
Envelhecimento , Cognição/fisiologia , Terapia por Exercício/métodos , Exercício Físico/psicologia , Propriocepção , Yoga , Afeto , Idoso , Idoso de 80 Anos ou mais , Estudos Cross-Over , Feminino , Humanos , Masculino , Memória de Curto Prazo/fisiologia
5.
Nutrients ; 12(8)2020 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-32731478

RESUMO

BACKGROUND: In whole foods, polyphenols exist alongside a wide array of other potentially bioactive phytochemicals. Yet, investigations of the effects of combinations of polyphenols with other phytochemicals are limited. OBJECTIVE: The current study investigated the effects of combining extracts of beetroot, ginseng and sage with phenolic-rich apple, blueberry and coffee berry extracts. DESIGN: This randomized, double-blind, placebo-controlled crossover design investigated three active beverages in 32 healthy adults aged 18-49 years. Each investigational beverage comprised extracts of beetroot, ginseng and sage. Each also contained a phenolic-rich extract derived from apple (containing 234 mg flavanols), blueberry (300 mg anthocyanins) or coffee berry (440 mg chlorogenic acid). Cognition, mood and CBF parameters were assessed at baseline and then again at 60, 180 and 360 min post-drink. RESULTS: Robust effects on mood and CBF were seen for the apple and coffee berry beverages, with increased subjective energetic arousal and hemodynamic responses being observed. Fewer effects were seen with the blueberry extract beverage. CONCLUSIONS: Either the combination of beetroot, ginseng and sage was enhanced by the synergistic addition of the apple and coffee berry extract (and to a lesser extent the blueberry extract) or the former two phenolic-rich extracts were capable of evincing the robust mood and CBF effects alone.


Assuntos
Circulação Cerebrovascular/efeitos dos fármacos , Cognição/efeitos dos fármacos , Flavonóis/farmacologia , Nitratos/farmacologia , Compostos Fitoquímicos/farmacologia , Adolescente , Adulto , Afeto/efeitos dos fármacos , Antocianinas/farmacologia , Beta vulgaris , Bebidas/análise , Mirtilos Azuis (Planta) , Ácido Clorogênico/farmacologia , Café , Estudos Cross-Over , Método Duplo-Cego , Feminino , Voluntários Saudáveis , Humanos , Masculino , Malus , Pessoa de Meia-Idade , Extratos Vegetais/farmacologia , Adulto Jovem
6.
Nutrients ; 10(10)2018 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-30274327

RESUMO

Cognitive and mood benefits of coffee are often attributed to caffeine. However, emerging evidence indicates behavioural effects of non-caffeine components within coffee, suggesting the potential for direct or synergistic effects of these compounds when consumed with caffeine in regular brewed coffee. The current randomised, placebo-controlled, double-blind, counterbalanced-crossover study compared the effects of regular coffee, decaffeinated coffee, and placebo on measures of cognition and mood. Age and sex effects were explored by comparing responses of older (61⁻80 years, N = 30) and young (20⁻34 years, N = 29) males and females. Computerised measures of episodic memory, working memory, attention, and subjective state were completed at baseline and 30 min post-drink. Regular coffee produced the expected effects of decreased reaction time and increased alertness when compared to placebo. When compared to decaffeinated coffee, increased digit vigilance accuracy and decreased tiredness and headache ratings were observed. Decaffeinated coffee also increased alertness when compared to placebo. Higher jittery ratings following regular coffee in young females and older males represented the only interaction of sex and age with treatment. These findings suggest behavioural activity of coffee beyond its caffeine content, raising issues with the use of decaffeinated coffee as a placebo and highlighting the need for further research into its psychoactive effects.


Assuntos
Afeto/efeitos dos fármacos , Cafeína/administração & dosagem , Café , Cognição/efeitos dos fármacos , Adulto , Idoso , Idoso de 80 Anos ou mais , Atenção/efeitos dos fármacos , Cafeína/análise , Estudos Cross-Over , Método Duplo-Cego , Fadiga , Feminino , Humanos , Aprendizagem/efeitos dos fármacos , Masculino , Pessoa de Meia-Idade , Placebos , Tempo de Reação/efeitos dos fármacos , Saliva/química
7.
Nutrients ; 10(8)2018 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-30087294

RESUMO

BACKGROUND: Extracts of several members of the monoterpene-rich Lamiaceae sub-family Nepetoideae, including those from the Salvia (sage), Melissa (Lemon balm) and Rosmarinus (rosemary) genera, evince cognitive and mood effects in humans that are potentially related to their effects on cholinergic and GABAergic neurotransmission. To date, despite promising in vitro properties, the cognitive and mood effects of the closely related Mentha spicata (spearmint) and Mentha piperita (peppermint) remain unexplored. This study therefore assessed the human cognitive/mood effects of the M. spicata/piperita essential oil with the most promising, brain-relevant in vitro properties according to pre-trial in vitro screening. Design: Organic spearmint and peppermint (Mentha spicata/piperita) essential oils were pre-screened for neurotransmitter receptor binding and acetylcholinesterase (AChE) inhibition. In a double-blind, placebo-controlled, balanced cross-over study, 24 participants (mean age 25.2 years) consumed single doses of encapsulated placebo and 50 µl and 100 µl of the most promising essential oil (peppermint with nicotinic/GABAA receptor binding and AChE inhibitory properties, that increased calcium influx in a CAD cell neuronal model). Psychological functioning was assessed with mood scales and a range of standardised, cognitively demanding tasks pre-dose and at 1, 3 and 6 h post-dose. Results: The highest (100 µL) dose of essential oil improved performance on the cognitively demanding Rapid Visual Information Processing task (RVIP) at 1 h and 3 h post-dose and both doses attenuated fatigue and improved performance of the Serial 3 s subtraction task at 3 h post-dose. Conclusion: Peppermint (Mentha piperita) essential oil with high levels of menthol/menthone and characteristic in vitro cholinergic inhibitory, calcium regulatory and GABAA/nicotinic receptor binding properties, beneficially modulated performance on demanding cognitive tasks and attenuated the increase in mental fatigue associated with extended cognitive task performance in healthy adults. Future investigations should consider investigating higher doses.


Assuntos
Afeto/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Cognição/efeitos dos fármacos , Mentha piperita , Nootrópicos/farmacologia , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologia , Terpenos/farmacologia , Adulto , Atenção/efeitos dos fármacos , Encéfalo/metabolismo , Sinalização do Cálcio/efeitos dos fármacos , Células Cultivadas , Inibidores da Colinesterase/isolamento & purificação , Inibidores da Colinesterase/farmacologia , Estudos Cross-Over , Método Duplo-Cego , Inglaterra , Feminino , Humanos , Masculino , Mentha piperita/química , Mentha spicata/química , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Testes Neuropsicológicos , Nootrópicos/isolamento & purificação , Óleos Voláteis/isolamento & purificação , Óleos de Plantas/isolamento & purificação , Receptores de GABA-A/efeitos dos fármacos , Receptores de GABA-A/metabolismo , Receptores Nicotínicos/efeitos dos fármacos , Receptores Nicotínicos/metabolismo , Terpenos/isolamento & purificação , Adulto Jovem
8.
Nutrients ; 10(8)2018 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-30060538

RESUMO

Epicatechin is a monomeric flavanol found in food sources such as tea, apples, berries and cocoa. A number of large-scale epidemiological studies have demonstrated an association between the consumption of these foods and cognitive function, as well as improved blood flow. The aim of this review is to summarise the evidence from intervention studies to clarify the effect of epicatechin on cognition and to consider the role of increased cerebral blood flow as a mechanism for any effects. The effects of epicatechin as consumed in cocoa are, therefore, reviewed here as this represents the only dietary source where it is purported to be the major active component. Our main findings are that a) the positive modulation of tasks that involve memory, executive function and processing speed in older adults; b) the cognitive benefits are more often shown in studies containing more than 50 mg epicatechin/day; and c) all studies with a duration of 28 days or longer in populations >50 years old demonstrate a cognitive improvement. However, as highlighted by this review, it is not currently possible to attribute effects solely to epicatechin without consideration of synergies. In order to overcome this issue, further studies examining the cognitive effects of epicatechin in isolation are required. The role of cerebral blood flow also requires further investigation through simultaneous measurement alongside cognitive function.


Assuntos
Cacau/química , Catequina/farmacologia , Circulação Cerebrovascular/efeitos dos fármacos , Cognição/efeitos dos fármacos , Função Executiva/efeitos dos fármacos , Memória/efeitos dos fármacos , Extratos Vegetais/farmacologia , Chocolate , Transtornos Cognitivos/prevenção & controle , Humanos , Tempo de Reação/efeitos dos fármacos
9.
Nutrients ; 9(12)2017 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-29215606

RESUMO

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.


Assuntos
Afeto/efeitos dos fármacos , Desjejum/psicologia , Cognição/efeitos dos fármacos , Alimentos Fortificados , Análise e Desempenho de Tarefas , Adulto , Atenção/efeitos dos fármacos , Cafeína/farmacologia , Método Duplo-Cego , Feminino , Glutamatos/farmacologia , Voluntários Saudáveis , Humanos , Masculino , Minerais/farmacologia , Tirosina/farmacologia , Vitaminas/farmacologia , Ácido alfa-Linolênico/farmacologia
11.
Nutr Neurosci ; 20(2): 135-151, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26618715

RESUMO

OBJECTIVES: A wild green-oats extract (Neuravena®) containing a range of potentially bioactive components, including flavonoids and triterpene saponins, has previously been shown to enhance animal stress responses and memory, and improve cognitive performance in humans at a dose of 1600 mg. Methods This double-blind, placebo-controlled, counterbalanced cross-over study assessed the effects of single doses of the green-oat extract (GOE) across a broad range of cognitive domains in healthy adults aged 40-65 years who self-reported that they felt that their memory had declined with age. Participants attended on six occasions, receiving a single dose of either placebo, 800, or 1600 mg GOE on each occasion, with the counterbalanced order of treatments repeated twice for each participant. Cognitive function was assessed with a range of computerized tasks measuring attention, spatial/working/episodic memory, and executive function pre-dose and at 1, 2.5, 4, and 6 hours post-dose. Results The results showed that 800mg GOE increased the speed of performance across post-dose assessments on a global measure including data from all of the timed tasks. It also improved performance of a delayed word recall task in terms of errors and an executive function task (Peg and Ball) in terms of decreased thinking time and overall completion time. Working memory span (Corsi blocks) was also increased, but only on the second occasion that this dose was taken. Discussion These results confirm the acute cognitive effects of GOE seen in previous research, and suggest that the optimal dose lies at or below 800 mg.


Assuntos
Envelhecimento , Avena/química , Disfunção Cognitiva/dietoterapia , Suplementos Nutricionais , Nootrópicos/uso terapêutico , Componentes Aéreos da Planta/química , Extratos Vegetais/uso terapêutico , Adulto , Idoso , Atenção , Avena/crescimento & desenvolvimento , Cápsulas , Cognição , Disfunção Cognitiva/fisiopatologia , Estudos Cross-Over , Suplementos Nutricionais/efeitos adversos , Método Duplo-Cego , Função Executiva , Humanos , Memória Episódica , Memória de Curto Prazo , Pessoa de Meia-Idade , Nootrópicos/administração & dosagem , Nootrópicos/efeitos adversos , Pacientes Desistentes do Tratamento , Componentes Aéreos da Planta/crescimento & desenvolvimento , Extratos Vegetais/administração & dosagem , Extratos Vegetais/efeitos adversos , Autorrelato , Memória Espacial
12.
Nutr Metab (Lond) ; 13: 11, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26870152

RESUMO

BACKGROUND: The brain is by far the most metabolically active organ in the body, with overall energy expenditure and local blood-supply closely related to neural activity. Both energy metabolism and cerebral vaso-dilation are dependent on adequate micronutrient status. This study investigated whether supplementation with ascending doses of multi-vitamin/minerals could modulate the metabolic and cerebral blood-flow consequences of performing cognitive tasks that varied in difficulty. METHODS: In this randomised, double-blind, placebo-controlled, parallel-groups study 97 healthy females (25-49 y), who were not selected on the basis of any nutritional parameters, received either placebo or one of two doses of multivitamins/minerals. Cerebral blood-flow (CBF) parameters in the frontal cortex, and total energy expenditure (TotalEnergy), carbohydrate and fat oxidation (CarbOxi/FatOxi), were measured during 5 tasks of graded cognitive difficulty and a control task (5 min per task) using Near-infrared spectroscopy (NIRS) and Indirect calorimetry of exhaled pulmonary gas (ICa) respectively. Assessments took place 60 min after the first dose and following eight weeks supplementation. RESULTS: During task performance supplementation with the first dose of micronutrients led to a dose-dependent increase in TotalEnergy and FatOxi throughout the post-dose assessment period following the higher dose, and increases in the total concentration of haemoglobin, a proxy measure for CBF, during task performance following the lower dose of vitamins/minerals (also containing coenzyme-Q10). Chronic supplementation over 8 weeks led to a dose-dependent increase in TotalEnergy during the task period. There were no interpretable effects on mood or cognitive performance. CONCLUSIONS: These results show that acute supplementation with micronutrients in healthy adults can modulate metabolic parameters and cerebral blood flow during cognitive task performance, and that the metabolic consequences are sustained during chronic supplementation. These findings suggest that both brain function and metabolism are amenable to micronutrient supplementation, even in adults who are assumed to have nutritional status typical of the population. TRIAL REGISTRATION: ClinicalTrials.gov - NCT02381964.

13.
Br J Nutr ; 114(9): 1427-37, 2015 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-26344014

RESUMO

Single doses of resveratrol have previously been shown to increase cerebral blood flow (CBF) with no clear effect on cognitive function or mood in healthy adults. Chronic resveratrol consumption may increase the poor bioavailability of resveratrol or otherwise potentiate its psychological effects. In this randomised, double-blind, placebo-controlled, parallel-groups study, a total of sixty adults aged between 18 and 30 years received either placebo or resveratrol for 28 d. On the 1st and 28th day of treatment, the performance of cognitively demanding tasks (serial subtractions, rapid visual information processing and 3-Back) (n 41 complete data sets) was assessed, alongside blood pressure (n 26) and acute (near-IR spectroscopy (NIRS)) and chronic (transcranial Doppler) measures of CBF (n 46). Subjective mood, sleep quality and health questionnaires were completed at weekly intervals (n 53/54). The results showed that the cognitive effects of resveratrol on day 1 were restricted to more accurate but slower serial subtraction task performance. The only cognitive finding on day 28 was a beneficial effect of resveratrol on the accuracy of the 3-Back task before treatment consumption. Subjective ratings of 'fatigue' were significantly lower across the entire 28 d in the resveratrol condition. Resveratrol also resulted in modulation of CBF parameters on day 1, as assessed by NIRS, and significantly increased diastolic blood pressure on day 28. Levels of resveratrol metabolites were significantly higher both before and after the day's treatment on day 28, in comparison with day 1. These results confirm the acute CBF effects of resveratrol and the lack of interpretable cognitive effects.


Assuntos
Afeto/efeitos dos fármacos , Circulação Cerebrovascular/efeitos dos fármacos , Cognição/efeitos dos fármacos , Suplementos Nutricionais , Sono/efeitos dos fármacos , Estilbenos/administração & dosagem , Adolescente , Adulto , Pressão Sanguínea/efeitos dos fármacos , Dieta , Método Duplo-Cego , Feminino , Frutas , Humanos , Masculino , Resveratrol , Inquéritos e Questionários , Análise e Desempenho de Tarefas , Verduras , Adulto Jovem
14.
Nutrients ; 7(8): 6109-27, 2015 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-26225993

RESUMO

Exercise undertaken in a fasted state can lead to higher post-exercise mental fatigue. The administration of a vitamin and mineral complex with guaraná (MVM + G) has been shown to attenuate mental fatigue and improve performance during cognitively demanding tasks. This placebo-controlled, double-blind, randomized, balanced cross-over study examined the effect of MVM + G consumed prior to morning exercise on cognitive performance, affect, exertion, and substrate metabolism. Forty active males (age 21.4 ± 3.0 year; body mass index (BMI) 24.0 ± 2.4 kg/m2; maximal oxygen consumption (V̇O2max) 57.6 ± 7.3 mL/min/kg) completed two main trials, consuming either MVM + G or placebo prior to a 30-min run at 60% V̇O2max. Supplementation prior to exercise led to a small but significant reduction in Rating of Perceived Exertion (RPE) during exercise compared to the placebo. The MVM + G combination also led to significantly increased accuracy of numeric working memory and increased speed of picture recognition, compared to the placebo. There were no significant effects of supplementation on any other cognitive or mood measures or on substrate metabolism during exercise. These findings demonstrate that consuming a vitamin and mineral complex containing guaraná, prior to exercise, can positively impact subsequent memory performance and reduce perceived exertion during a moderate-intensity run in active males.


Assuntos
Afeto/efeitos dos fármacos , Cognição/efeitos dos fármacos , Suplementos Nutricionais , Fadiga Mental/prevenção & controle , Micronutrientes/farmacologia , Paullinia , Corrida/fisiologia , Adolescente , Adulto , Estudos Cross-Over , Método Duplo-Cego , Jejum , Humanos , Masculino , Memória/efeitos dos fármacos , Minerais/farmacologia , Consumo de Oxigênio , Resistência Física/efeitos dos fármacos , Esforço Físico/efeitos dos fármacos , Extratos Vegetais/farmacologia , Reconhecimento Psicológico/efeitos dos fármacos , Corrida/psicologia , Vitaminas/farmacologia , Adulto Jovem
15.
Physiol Behav ; 149: 149-58, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26037632

RESUMO

Nitrate derived from vegetables is consumed as part of a normal diet and is reduced endogenously via nitrite to nitric oxide. It has been shown to improve endothelial function, reduce blood pressure and the oxygen cost of sub-maximal exercise, and increase regional perfusion in the brain. The current study assessed the effects of dietary nitrate on cognitive performance and prefrontal cortex cerebral blood-flow (CBF) parameters in healthy adults. In this randomised, double-blind, placebo-controlled, parallel-groups study, 40 healthy adults received either placebo or 450 ml beetroot juice (~5.5 mmol nitrate). Following a 90 minute drink/absorption period, participants performed a selection of cognitive tasks that activate the frontal cortex for 54 min. Near-Infrared Spectroscopy (NIRS) was used to monitor CBF and hemodynamics, as indexed by concentration changes in oxygenated and deoxygenated-haemoglobin, in the frontal cortex throughout. The bioconversion of nitrate to nitrite was confirmed in plasma by ozone-based chemi-luminescence. Dietary nitrate modulated the hemodynamic response to task performance, with an initial increase in CBF at the start of the task period, followed by consistent reductions during the least demanding of the three tasks utilised. Cognitive performance was improved on the serial 3s subtraction task. These results show that single doses of dietary nitrate can modulate the CBF response to task performance and potentially improve cognitive performance, and suggest one possible mechanism by which vegetable consumption may have beneficial effects on brain function.


Assuntos
Córtex Cerebral/irrigação sanguínea , Cognição/fisiologia , Suplementos Nutricionais , Hemodinâmica/fisiologia , Hemoglobinas/metabolismo , Nitratos/administração & dosagem , Adolescente , Adulto , Afeto , Análise de Variância , Pressão Sanguínea/fisiologia , Cognição/efeitos dos fármacos , Estudos Transversais , Método Duplo-Cego , Feminino , Sucos de Frutas e Vegetais , Frequência Cardíaca/fisiologia , Humanos , Masculino , Testes Neuropsicológicos , Nitratos/sangue , Espectroscopia de Luz Próxima ao Infravermelho , Adulto Jovem
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