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1.
Public Health Nutr ; : 1-38, 2024 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-39462820

RESUMO

OBJECTIVE: Evaluate knowledge and beliefs about dietary nitrate among United Kingdom (UK)-based adults. DESIGN: An online questionnaire was administered to evaluate knowledge and beliefs about dietary nitrate. Overall knowledge of dietary nitrate was quantified using a 21-point Nitrate Knowledge Index. Responses were compared between sociodemographic groups. SETTING: UK. PARTICIPANTS: A nationally representative sample of three hundred adults. RESULTS: Only 19% of participants had heard of dietary nitrate prior to completing the questionnaire. Most participants (∼70%) were unsure about the effects of dietary nitrate on health parameters (e.g., blood pressure, cognitive function, cancer risk) or exercise performance. Most participants were unsure of the average population intake (78%) and acceptable daily intake (ADI) (83%) of nitrate. Knowledge of dietary sources of nitrate was generally low, with only ∼30% of participants correctly identifying foods with higher/lower nitrate contents. Almost none of the participants had deliberately purchased, or avoided purchasing, a food based around its nitrate content. Nitrate Knowledge Index scores were generally low (median[IQR]: 5[8]), but were significantly higher in individuals who were currently employed vs. unemployed (median[IQR]: 5[7]vs.4[7]; p<0.001), in those with previous nutrition education vs. no nutrition education (median[IQR]: 6[7]vs.4[8]; p=0.012), and in individuals who had heard of nitrate prior to completing the questionnaire vs. those who had not (median [IQR]: 9[8]vs.4[7]; p<0.001). CONCLUSIONS: This study demonstrates low knowledge around dietary nitrate in UK-based adults. Greater education around dietary nitrate may be valuable to help individuals make more informed decisions about their consumption of this compound.

2.
Lancet Healthy Longev ; 5(6): e406-e421, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38824956

RESUMO

BACKGROUND: More than 57 million people have dementia worldwide. Evidence indicates a change in dementia prevalence and incidence in high-income countries, which is likely to be due to improved life-course population health. Identifying key modifiable risk factors for dementia is essential for informing risk reduction and prevention strategies. We therefore aimed to estimate the population attributable fraction (PAF) for dementia associated with modifiable risk factors. METHODS: In this systematic review and meta-analysis, we searched Embase, MEDLINE, and PsycINFO, via Ovid, from database inception up to June 29, 2023, for population-derived or community-based studies and reviews reporting a PAF value for one or more modifiable risk factor for later-life dementia (prevalent or incident dementia in people aged ≥60 years), with no restrictions on dementia subtype, the sex or baseline age of participants, or the period of study. Articles were independently screened for inclusion by four authors, with disagreements resolved through consensus. Data including unweighted and weighted PAF values (weighted to account for communality or overlap in risk) were independently extracted into a predefined template by two authors and checked by two other authors. When five or more unique studies investigated a given risk factor or combination of the same factors, random-effects meta-analyses were used to calculate a pooled PAF percentage estimate for the factor or combination of factors. The review protocol was registered on PROSPERO, CRD42022323429. FINDINGS: 4024 articles were identified, and 74 were included in our narrative synthesis. Overall, PAFs were reported for 61 modifiable risk factors, with sufficient data available for meta-analysis of 12 factors (n=48 studies). In meta-analyses, the highest pooled unweighted PAF values were estimated for low education (17·2% [95% CI 14·4-20·0], p<0·0001), hypertension (15·8% [14·7-17·1], p<0·0001), hearing loss (15·6% [10·3-20·9], p<0·0001), physical inactivity (15·2% [12·8-17·7], p<0·0001), and obesity (9·4% [7·3-11·7], p<0·0001). According to weighted PAF values, low education (9·3% [6·9-11·7], p<0·0001), physical inactivity (7·3% [3·9-11·2], p=0·0021), hearing loss (7·2% [5·2-9·7], p<0·0001), hypertension (7·1% [5·4-8·8], p<0·0001), and obesity (5·3% [3·2-7·4], p=0·0001) had the highest pooled estimates. When low education, midlife hypertension, midlife obesity, smoking, physical inactivity, depression, and diabetes were combined (Barnes and Yaffe seven-factor model; n=9 studies), the pooled unweighted and weighted PAF values were 55·0% (46·5-63·5; p<0·0001) and 32·0% (26·6-37·5; p<0·0001), respectively. The pooled PAF values for most individual risk factors were higher in low-income and middle-income countries (LMICs) versus high-income countries. INTERPRETATION: Governments need to invest in a life-course approach to dementia prevention, including policies that enable quality education, health-promoting environments, and improved health. This investment is particularly important in LMICs, where the potential for prevention is high, but resources, infrastructure, budgets, and research focused on ageing and dementia are limited. FUNDING: UK Research and Innovation (Medical Research Council).


Assuntos
Demência , Humanos , Demência/epidemiologia , Demência/prevenção & controle , Demência/etiologia , Fatores de Risco
3.
Support Care Cancer ; 32(7): 418, 2024 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-38849604

RESUMO

PURPOSE: Patients with cancer often experience nutritional challenges and are vulnerable to muscle mass loss. While substantial research is directed towards understanding how nutritional interventions affect clinical outcomes, insights into patients' personal experiences during these trials remain limited. This qualitative study aimed to gain a deeper understanding of how participation in the Protein Recommendations to Increase Muscle (PRIMe) trial affected patients' relationships with food. METHODS: A subset of patients who completed a minimum of one follow-up visit in the PRIMe trial participated in a semi-structured interview about their experience implementing dietary modifications to increase protein intake. Data from 26 patients with a recent diagnosis of stage II-IV colorectal cancer (non-cachectic) were included. Interviews were audio recorded, transcribed verbatim, and qualitative content analysis was applied. RESULTS: Most patients were male (65.4%) with stage II or III (69.2%) colorectal cancer and were a mean age of 57 ± 10 years. Five key themes emerged to provide a deeper understanding of patients' relationship with food after the PRIMe trial: (1) new positive perspectives on nutrition and coping with a cancer diagnosis; (2) embracing a comprehensive approach to food and nutrition; (3) facilitators promoting adherence to the intervention; (4) barriers challenging adherence to the intervention; and (5) shaping future dietary intake. CONCLUSION: This qualitative study explored the emotional and psychological effects of a clinical nutrition trial on patients, focusing on their relationship with food. It underscored the trial's comprehensive intervention and its enduring influence on patients, extending beyond the immediate intervention phase. The role of current perspectives, motivation, and knowledge acquisition on ability to adhere to dietary changes to increase protein intake were emphasized by patients and are key considerations for both clinicians and researchers. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT02788955; registration posted on 2016-06-02.


Assuntos
Neoplasias Colorretais , Proteínas Alimentares , Pesquisa Qualitativa , Humanos , Neoplasias Colorretais/dietoterapia , Neoplasias Colorretais/psicologia , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Proteínas Alimentares/administração & dosagem , Adaptação Psicológica , Adulto
4.
Nutrition ; 125: 112494, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38843564

RESUMO

BACKGROUND AND AIMS: Measurement of body composition using computed tomography (CT) scans may be a viable clinical tool for low muscle mass assessment in oncology. However, longitudinal assessments are often infeasible with CT. Clinically accessible body composition technologies can be used to track changes in fat-free mass (FFM) or muscle, though their accuracy may be impacted by cancer-related physiological changes. The purpose of this study was to examine the agreement among accessible body composition method with criterion methods for measures of whole-body FFM measurements and, when possible, muscle mass for the classification of low muscle in patients with cancer. METHODS: Patients with colorectal cancer were recruited to complete measures of whole-body DXA, air displacement plethysmography (ADP), and bioelectrical impedance analysis (BIA). These measures were used alone, or in combination to construct the criterion multicompartment (4C) mode for estimating FFM. Patients also underwent abdominal CT scans as part of routine clinical assessment. Agreement of each method with 4C model was analyzed using mean constant error (CE = criterion - alternative), linear regression including root mean square error (RMSE), Bland-Altman limits of agreement (LoA) and mean percentage difference (MPD). Additionally, appendicular lean soft tissue index (ALSTI) measured by DXA and predicted by CT were compared for the absolute agreement, while the ALSTI values and skeletal muscle index by CT were assessed for agreement on the classification of low muscle mass. RESULTS: Forty-five patients received all measures for the 4C model and 25 had measures within proximity of clinical CT measures. Compared to 4C, DXA outperformed ADP and BIA by showing the strongest overall agreement (CE = 1.96 kg, RMSE = 2.45 kg, MPD = 98.15 ± 2.38%), supporting its use for body composition assessment in patients with cancer. However, CT cutoffs for skeletal muscle index or CT-estimated ALSTI were lower than DXA ALSTI (average 1.0 ± 1.2 kg/m2) with 24.0% to 32.0% of patients having a different low muscle classification by CT when compared to DXA. CONCLUSIONS: Despite discrepancies between clinical body composition assessment and the criterion multicompartment model, DXA demonstrates the strongest agreement with 4C. Disagreement between DXA and CT for low muscle mass classification prompts further evaluation of the measures and cutoffs used with each technique. Multicompartment models may enhance our understanding of body composition variations at the individual patient level and improve the applicability of clinically accessible technologies for classification and monitoring change over time.


Assuntos
Absorciometria de Fóton , Composição Corporal , Neoplasias Colorretais , Impedância Elétrica , Músculo Esquelético , Tomografia Computadorizada por Raios X , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Absorciometria de Fóton/métodos , Idoso , Tomografia Computadorizada por Raios X/métodos , Neoplasias Colorretais/diagnóstico por imagem , Músculo Esquelético/diagnóstico por imagem , Músculo Esquelético/fisiopatologia , Pletismografia/métodos , Adulto
5.
Eur J Clin Nutr ; 78(6): 534-540, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38472359

RESUMO

BACKGROUND: The evidence on the relationship between adiposity and disease outcomes in paediatric Crohn's disease (CD) is limited and lacks consensus. AIM: To investigate the relationship between (a) body mass index (BMI) and clinical CD outcomes (hospitalisation, surgery, disease behaviour, biologic use, extra-intestinal manifestations (EIMs)) and (b) the age of CD onset with clinical outcomes. DESIGN: Clinical outcomes were examined in CD patients diagnosed at age <17 years and enroled in the National Institute for Health Research IBD-UK BioResource at a median age of 24 years. All outcomes and BMI were recorded at the time of enrolment. Participants were categorised into normal (<25 kg/m2) and high (≥25 kg/m2) BMI. Age at disease diagnosis was categorised into pre-puberty/early puberty (<11 years), puberty (11-14 years) and post-puberty (15-17 years). Spearman rank correlation was used to test the associations between continuous variables and chi-square test to compare categorical variables. RESULTS: 848 participants with CD were included (51.8% males) and median age at diagnosis was 14 years. Participants with high BMI experienced a greater frequency of EIMs (P = 0.05) than those with low BMI (1 type of EIM: 18.5% vs. 13.2%, respectively; ≥2 types of EIMs: 7.8% vs. 5.6%, respectively). Age at diagnosis and BMI showed weak correlations with corticosteroid use (ρ = 0.08, P = 0.03 and ρ = -0.09, P = 0.01; respectively). An early diagnosis (<11 years) was associated with higher occurrence of stenosing and penetrating disease behaviour (P = 0.01) and hospitalisations (P < 0.001). CONCLUSIONS: A higher BMI and an earlier age of disease onset are associated with worse CD clinical presentation.


Assuntos
Idade de Início , Índice de Massa Corporal , Doença de Crohn , Humanos , Masculino , Feminino , Adolescente , Reino Unido/epidemiologia , Criança , Adulto Jovem
6.
J Nutr ; 154(2): 469-478, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38048992

RESUMO

BACKGROUND: Aging and vitamin D deficiency have been associated with reduced nitric oxide (NO) synthesis and impaired endothelial function (EF) but the evidence in humans remains weak. OBJECTIVES: Two independent cross-sectional studies were designed to evaluate the association between age, sex, and plasma vitamin D concentrations with physiological and biochemical biomarkers of NO synthesis and EF in young and older healthy participants (Study 1) and in overweight and obese postmenopausal females (Study 2). METHODS: In Study 1, 40 young (20-49 y) and older (50-75 y) males and females (10 participants per age and sex group) were included. Resting blood pressure and ear-to-finger peripheral pulse wave velocity (PWV) were measured. A stable-isotopic method was used to determine whole-body NO production. Plasma 25-hydroxyvitamin D (25(OH)D), nitrate, nitrite, and asymmetric dimethylarginine (ADMA) concentrations were determined. In Study 2, 80 older overweight and obese females (age 61.2 ± 6.2 y, body mass index 29.5 ± 4.4 kg/m2) were recruited. Postocclusion reactive hyperemia (PORH) and peripheral PWV were measured. Plasma concentrations of 25(OH)D, nitrate, cyclic guanosine monophosphate, 3-nitrotyrosine (3-NT), endothelin-1, vascular endothelial growth factor, and ADMA were determined. RESULTS: In Study 1, whole-body NO production was significantly greater in young compared with older participants (0.61 ± 0.30 µmol·h-1·kg-1 compared with 0.39 ± 0.10 µmol·h-1·kg-1, P = 0.01) but there was no evidence of a sex difference (P = 0.81). Plasma 25(OH)D concentration was not associated with PWV (r = 0.18, P = 0.28) or whole-body NO production (r = -0.20, P = 0.22). Plasma ADMA concentration was associated positively with age (r = 0.35, P = 0.03) and negatively with whole-body NO production (r = -0.33, P = 0.04). In Study 2, age was associated with lower PORH (r = -0.28, P = 0.02) and greater ADMA concentrations (r = 0.22, P = 0.04). Plasma 25(OH)D concentration was inversely associated with 3-NT concentrations (r = -0.31, P = 0.004). CONCLUSIONS: Older age was associated with lower whole-body NO production. Plasma vitamin D concentrations were not associated with NO production or markers of EF but showed a weak, significant correlation with oxidative stress in postmenopausal overweight females.


Assuntos
Óxido Nítrico , Deficiência de Vitamina D , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Sobrepeso , Nitratos , Estudos Transversais , Análise de Onda de Pulso , Fator A de Crescimento do Endotélio Vascular , Envelhecimento , Vitamina D , Obesidade , Vitaminas
7.
Crit Rev Food Sci Nutr ; : 1-13, 2023 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-38104588

RESUMO

Carrots are main dietary sources of several potential anti-cancer compounds, including polyacetylenes, while ß-carotene has shown no benefits in controlled cancer trials. Accordingly, associations between carrot intake and cancer incidence were quantified, where necessary using α-carotene as a non-causal biomarker of carrot consumption, by searching for studies published before June 2022 reporting risk estimates for relationships of cancer incidence with carrot intake or α-carotene intake or α-carotene plasma concentration, supplemented with hand searches of included studies and reviews. Meta-analyses comparing highest and lowest reported intakes in prospective studies using a random-effects model estimated summary relative risks (RRs) with 95% confidence intervals (CIs), separately for carrot intake or α-carotene plasma concentration, and the corresponding dose-responses. Of 198 observational studies, in 50 prospective studies with 52000 cases recording carrot intake, the cancer-risk was substantially reduced (RR 0.90, 95% CI 0.87-0.94, p ˂ 0·00004). In 30 prospective studies with 9331 cases reporting plasma α-carotene levels, summary RR was 0.80 (0.72-0.89, p ˂ 0·00006). For both exposure types, inter-study heterogeneity was moderate, interaction with cancer types insignificant, and the dose-response significant (p ˂ 0·01). In conclusion, carrot consumption is robustly associated with decreased cancer-risk; carrot consumption should be encouraged, and the causal mechanisms further investigated.

8.
Eur J Clin Nutr ; 77(10): 927-940, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37491453

RESUMO

Endothelial dysfunction is closely linked to the development of atherosclerosis. This systematic review and meta-analysis reviewed the evidence on the effect of weight loss, achieved by dietary-based interventions, on biomarkers of endothelial function (EF). Two databases (Medline, Embase) were searched from inception until November 2022 for studies that met the following criteria: 1) adult subjects (≥ 18 years) without exclusion for health status, 2) dietary interventions for weight loss, and 3) measurements of changes in EF biomarkers. Random-effect meta-analysis and meta-regression were performed. Thirty-seven articles including 1449 participants were included in the systematic review. Study duration ranged from 3-52 weeks. Overall, weight loss significantly improved biomarkers of EF [standardised mean difference (SMD):0.65; 95%CI:0.49,0.81; P < 0.001;I2 = 91.9%]. Subgroup analyses showed weight loss significantly improved levels of E-selectin (P < 0.001), intercellular adhesion molecule-1 (ICAM-1) (P < 0.001), vascular cell adhesion molecule-1 (VCAM-1) (P < 0.001), nitrite/nitrate (NOx) (P < 0.001) and vascular endothelial growth factor (VEGF) (P < 0.001). Conversely, there was no significant improvement for von Willebrand Factor (vWF). Meta-regression analysis revealed that changes in EF biomarkers were not affected by age, BMI, quality of the studies or the amount of weight lost. A significant heterogeneity was observed for the effects of weight loss on changes in EF biomarkers. Dietary-induced weight loss may be associated with biomarkers changes indicating an improvement of EF, and it may represent a potential strategy to reduce atherosclerotic risk.


Assuntos
Molécula 1 de Adesão de Célula Vascular , Fator A de Crescimento do Endotélio Vascular , Adulto , Humanos , Biomarcadores , Análise de Regressão , Redução de Peso
9.
Am J Clin Nutr ; 118(2): 422-432, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37290740

RESUMO

BACKGROUND: Total energy expenditure (TEE) determines energy requirements, but objective data in patients with cancer are limited. OBJECTIVES: We aimed to characterize TEE, investigate its predictors, and compare TEE with cancer-specific predicted energy requirements. METHODS: This cross-sectional analysis included patients with stages II-IV colorectal cancer from the Protein Recommendation to Increase Muscle (PRIMe) trial. TEE was assessed by 24-h stay in a whole-room indirect calorimeter before dietary intervention and compared with cancer-specific predicted energy requirements (25-30 kcal/kg). Generalized linear models, paired-samples t tests, and Pearson correlation were applied. RESULTS: Thirty-one patients (56 ± 10 y; body mass index [BMI]: 27.9 ± 5.5 kg/m2; 68% male) were included. Absolute TEE was higher in males (mean difference: 391 kcal/d; 95% CI: 167, 616 kcal/d; P < 0.001), patients with colon cancer (mean difference: 279 kcal/d; 95% CI: 73, 485 kcal/d; P = 0.010), and patients with obesity (mean difference: 393 kcal/d; 95% CI: 182, 604 kcal/d; P < 0.001). Appendicular lean soft tissue (ß: 46.72; 95% CI: 34.27, 59.17; P < 0.001) and tumor location (colon-ß: 139.69; 95% CI: 19.44, 259.95; P = 0.023) independently predicted TEE when adjusted for sex. Error between measured TEE and energy requirements predicted by 25 kcal/kg (mean difference: 241 kcal/d; 95% CI: 76, 405 kcal/d; P = 0.010) or 30 kcal/kg (mean difference: 367 kcal/d; 95% CI: 163, 571 kcal/d; P < 0.001) was higher for patients with obesity, and proportional error was observed (25 kcal/kg: r = -0.587; P < 0.001; and 30 kcal/kg: r = -0.751; P < 0.001). TEE (mean difference: 25 kcal/kg; 95% CI: 24, 27 kcal/kg) was below predicted requirements using 30 kcal/kg (-430 ± 322 kcal/d; P < 0.001). CONCLUSIONS: This is the largest study to assess TEE of patients with cancer using whole-room indirect calorimeter and highlights the need for improved assessment of energy requirements in this population. Energy requirements predicted using 30 kcal/kg overestimated TEE by 1.44 times in a controlled sedentary environment and TEE was outside of the predicted requirement range for most. Special considerations are warranted when determining TEE of patients with colorectal cancer, such as BMI, body composition, and tumor location. This is a baseline cross-sectional analysis from a clinical trial registered at clinicaltrials.gov as NCT02788955 (https://clinicaltrials.gov/ct2/show/NCT02788955).


Assuntos
Neoplasias Colorretais , Metabolismo Energético , Feminino , Humanos , Masculino , Índice de Massa Corporal , Calorimetria Indireta , Estudos Transversais , Metabolismo Energético/fisiologia , Obesidade , Pessoa de Meia-Idade , Idoso
10.
J Acad Nutr Diet ; 123(3): 407-416, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36002111

RESUMO

BACKGROUND: Dietary changes often accompany management of a cancer diagnosis, but how and why patients with colorectal cancer (CRC) make dietary decisions requires further investigation. OBJECTIVE: To learn about patients' food-related beliefs and understand whether and why dietary changes were made by patients starting chemotherapy after a CRC diagnosis. DESIGN: A qualitative semi-structured interview study was conducted as a secondary analysis among a subset of patients with stages II-IV CRC enrolled at baseline in a randomized controlled trial. PARTICIPANTS/SETTING: Twenty-nine patients participated in the interview. Data were collected at the University of Alberta (Edmonton, Alberta, Canada) from 2016-2019 before any trial intervention. QUALITATIVE DATA ANALYSIS: Audio-recorded interviews were transcribed verbatim then coded inductively by two research team members. Qualitative content analysis was applied to capture emergent themes. RESULTS: Patients reported varied degrees of dietary change that stemmed from internal and external influences. Four main themes emerged to describe patients' dietary decisions after a CRC diagnosis: 1) Medical Influences: eating to live; 2) Health Beliefs: connecting lived experiences with new realities; 3) Static Diets: no changes postdiagnosis; and 4) Navigating External Influences: confluence of personal agency and social constraints. CONCLUSION: The extent to which patients altered their dietary choices depended on perspectives and beliefs. These included the degree to which dietary decisions provided some agency (ie, feeling of control) for dealing with physical ramifications of cancer treatment, individuals' personal understandings of healthy foods, and the role of diet in managing their new physical reality postdiagnosis. This information provides registered dietitian nutritionists and health care providers with insight into dietary intentions of select patients being treated for CRC. These findings can guide future research focused on effective strategies for streamlined nutritional support that aligns with patient needs.


Assuntos
Neoplasias Colorretais , Dieta , Humanos , Alimentos , Neoplasias Colorretais/diagnóstico , Pesquisa Qualitativa , Alberta
11.
Sports Med ; 52(10): 2537-2558, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35604567

RESUMO

INTRODUCTION: Dietary inorganic nitrate is a popular nutritional supplement, which increases nitric oxide bioavailability and may improve exercise performance. Despite over a decade of research into the effects of dietary nitrate supplementation during exercise there is currently no expert consensus on how, when and for whom this compound could be recommended as an ergogenic aid. Moreover, there is no consensus on the safe administration of dietary nitrate as an ergogenic aid. This study aimed to address these research gaps. METHODS: The modified Delphi technique was used to establish the views of 12 expert panel members on the use of dietary nitrate as an ergogenic aid. Over three iterative rounds (two via questionnaire and one via videoconferencing), the expert panel members voted on 222 statements relating to dietary nitrate as an ergogenic aid. Consensus was reached when > 80% of the panel provided the same answer (i.e. yes or no). Statements for which > 80% of the panel cast a vote of insufficient evidence were categorised as such and removed from further voting. These statements were subsequently used to identify directions for future research. RESULTS: The 12 panel members contributed to voting in all three rounds. A total of 39 statements (17.6%) reached consensus across the three rounds (20 yes, 19 no). In round one, 21 statements reached consensus (11 yes, 10 no). In round two, seven further statements reached consensus (4 yes, 3 no). In round three, an additional 11 statements reached consensus (5 yes, 6 no). The panel agreed that there was insufficient evidence for 134 (60.4%) of the statements, and were unable to agree on the outcome of the remaining statements. CONCLUSIONS: This study provides information on the current expert consensus on dietary nitrate, which may be of value to athletes, coaches, practitioners and researchers. The effects of dietary nitrate appear to be diminished in individuals with a higher aerobic fitness (peak oxygen consumption [V̇O2peak] > 60 ml/kg/min), and therefore, aerobic fitness should be taken into account when considering use of dietary nitrate as an ergogenic aid. It is recommended that athletes looking to benefit from dietary nitrate supplementation should consume 8-16 mmol nitrate acutely or 4-16 mmol/day nitrate chronically (with the final dose ingested 2-4 h pre-exercise) to maximise ergogenic effects, taking into consideration that, from a safety perspective, athletes may be best advised to increase their intake of nitrate via vegetables and vegetable juices. Acute nitrate supplementation up to ~ 16 mmol is believed to be safe, although the safety of chronic nitrate supplementation requires further investigation. The expert panel agreed that there was insufficient evidence for most of the appraised statements, highlighting the need for future research in this area.


Assuntos
Substâncias para Melhoria do Desempenho , Consenso , Técnica Delphi , Suplementos Nutricionais , Humanos , Nitratos
12.
Free Radic Biol Med ; 176: 105-117, 2021 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-34562607

RESUMO

The traditional Mediterranean diet (MedDiet), rich in minimally processed plant foods and fish, has been widely recognized to be one of the healthiest diets. Data from multiple randomized clinical trials have demonstrated its powerful effect against oxidative stress, inflammation and the development and progression of cardiovascular disease, type 2 diabetes, and other metabolic conditions that play a crucial role in the pathogenesis of neurodegenerative diseases. The protecting effects of the MedDiet against cognitive decline have been investigated in several observational and experimental studies. Data from observational studies suggest that the MedDiet may represent an effective dietary strategy for the early prevention of dementia, although these findings require further substantiation in clinical trials which have so far produced inconclusive results. Moreover, as we discuss in this review, accumulating data emphasizes the importance of: 1) maintaining an optimal nutritional and metabolic status for the promotion of healthy cognitive aging, and 2) implementing cognition-sparing dietary and lifestyle interventions during early time-sensitive windows before the pathological cascades turn into an irreversible state. In summary, components of the MedDiet pattern, such as essential fatty acids, polyphenols and vitamins, have been associated with reduced oxidative stress and the current evidence from observational studies seems to assign to the MedDiet a beneficial role in promoting brain health; however, results from clinical trials have been inconsistent. While we advocate for longitudinal analyses and for larger and longer clinical trials to be conducted, we assert our interim support to the use of the MedDiet as a protective dietary intervention for cognitive function based on its proven cardiovascular and metabolic benefits.


Assuntos
Doenças Cardiovasculares , Disfunção Cognitiva , Diabetes Mellitus Tipo 2 , Dieta Mediterrânea , Animais , Doenças Cardiovasculares/prevenção & controle , Cognição
13.
BMJ Open ; 11(2): e042823, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33550254

RESUMO

INTRODUCTION: Dementia prevalence continues to increase, and effective interventions are needed to prevent, delay or slow its progression. Higher adherence to the Mediterranean diet (MedDiet) and increased physical activity (PA) have been proposed as strategies to facilitate healthy brain ageing and reduce dementia risk. However, to date, there have been no dementia prevention trials in the UK focussed on combined dietary and PA interventions. This study aims to: (1) assess feasibility and acceptability of a theory-underpinned digital and group-based intervention for dementia risk reduction in an 'at risk' UK cohort; (2) evaluate behaviour change responses to the intervention; and, (3) provide information on cognitive, neurological, vascular and physiological outcomes to inform the design of a follow-on, full-scale efficacy trial. METHODS: One hundred and eight participants aged 55 to 74 years with a QRISK2 score of ≥10% will be recruited to take part in this 24-week multi-site study. Participants will be randomised into three parallel arms: (1) Control; (2) MedDiet; and, (3) MedDiet+PA. The study will evaluate a personalised website, group session and food delivery intervention to increase MedDiet adherence and PA in older adults at risk of dementia. Diet and PA will be monitored prior to, during and following the intervention. Feasibility, acceptability and hypothesised mediators will be assessed in addition to measures of cognitive function, brain structure/perfusion (MRI), vascular function and metabolic markers (blood, urine and faecal) prior to, and following, the intervention. DISCUSSION: This trial will provide insights into the feasibility, acceptability and mechanism of effect of a multi-domain intervention focussed on the MedDiet alone and PA for dementia risk reduction in an 'at risk' UK cohort. ETHICS AND DISSEMINATION: The study has received NHS REC and HRA approval (18/NI/0191). Findings will be disseminated via conference presentations, public lectures, and peer-reviewed publications. TRIAL REGISTRATION DETAILS: ClinicalTrials.gov NCT03673722.


Assuntos
Demência , Dieta Mediterrânea , Idoso , Demência/prevenção & controle , Exercício Físico , Estudos de Viabilidade , Humanos , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Reino Unido
14.
Clin Nutr ESPEN ; 41: 175-185, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33487262

RESUMO

BACKGROUND: Severe muscle mass (MM) loss is a defining feature of cancer observed across all types and stages of disease and is an independent predictor of poor clinical outcomes including higher incidences of chemotherapy toxicity and decreased survival. Protein is essential to build MM, yet the optimal amount for preventing or treating muscle loss in patients with cancer remains undefined. METHODS: The Protein Recommendation to Increase Muscle (PRIMe) study is a single-center, two-armed, parallel, randomized, controlled pilot trial that assesses the feasibility of utilizing a high protein (HP) diet to positively impact clinical outcomes in people undergoing chemotherapy to treat colorectal cancer. Forty patients with newly diagnosed stage II-IV colorectal cancer who are scheduled to receive chemotherapy will be included. Participants are randomly assigned to a HP or normal protein (NP) diet for twelve weeks. The HP and NP groups receive nutrition recommendations to achieve 2.0 g of protein per kilogram of body weight per day (g∙kg-1∙d-1) and 1.0 g⋅kg-1⋅d-1, respectively. These values refer to the upper and lower recommended range of protein intake for people with cancer. Energy recommendations are based on measured energy expenditure. Assessments are completed within two weeks of starting chemotherapy (baseline), at week 6, and at week 12. Changes to skeletal MM, physical function, anthropometrics, body composition, muscle strength, physical activity, energy metabolism, metabolic markers, nutritional status, quality of life, readiness to change and psychosocial determinants of behavioural change are assessed between the HP and NP groups. Feasibility of the nutritional intervention is assessed by change in MM as a surrogate marker. CONCLUSIONS: This evidence-based study investigates the feasibility of increasing protein intake following a diagnosis of cancer on clinical outcomes during treatment for colorectal cancer. This study will inform larger trials assessing the impact of increasing protein intake in cancer to determine their importance and integration into standard clinical care for people with cancer.


Assuntos
Neoplasias Colorretais , Dieta Rica em Proteínas , Neoplasias Colorretais/tratamento farmacológico , Estudos de Viabilidade , Humanos , Músculo Esquelético , Projetos Piloto , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como Assunto
15.
J Alzheimers Dis ; 79(2): 743-762, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33361599

RESUMO

BACKGROUND: Mild cognitive impairment (MCI) is a cognitive state associated with increased risk of dementia. Little research on MCI exists from low-and middle-income countries (LMICs), despite high prevalence of dementia in these settings. OBJECTIVE: This systematic review aimed to review epidemiological reports to determine the prevalence of MCI and its associated risk factors in LMICs. METHODS: Medline, Embase, and PsycINFO were searched from inception until November 2019. Eligible articles reported on MCI in population or community-based studies from LMICs and were included as long as MCI was clearly defined. RESULTS: 5,568 articles were screened, and 78 retained. In total, n = 23 different LMICs were represented; mostly from China (n = 55 studies). Few studies were from countries defined as lower-middle income (n = 14), low income (n = 4), or from population representative samples (n = 4). There was large heterogeneity in how MCI was diagnosed; with Petersen criteria the most commonly applied (n = 26). Prevalence of amnesic MCI (aMCI) (Petersen criteria) ranged from 0.6%to 22.3%. Similar variability existed across studies using the International Working Group Criteria for aMCI (range 4.5%to 18.3%) and all-MCI (range 6.1%to 30.4%). Risk of MCI was associated with demographic (e.g., age), health (e.g., cardio-metabolic disease), and lifestyle (e.g., social isolation, smoking, diet and physical activity) factors. CONCLUSION: Outside of China, few MCI studies have been conducted in LMIC settings. There is an urgent need for population representative epidemiological studies to determine MCI prevalence in LMICs. MCI diagnostic methodology also needs to be standardized. This will allow for cross-study comparison and future resource planning.


Assuntos
Disfunção Cognitiva/epidemiologia , Países em Desenvolvimento/estatística & dados numéricos , Idoso , Disfunção Cognitiva/etiologia , Humanos , Pessoa de Meia-Idade , Prevalência , Fatores de Risco
16.
Contemp Clin Trials Commun ; 18: 100571, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32405570

RESUMO

BACKGROUND: Nitrate-rich food can increase NO production and may induce positive effects on brain function. This study examined the feasibility of a randomized clinical trial (RCT) testing the effects of prolonged consumption of incremental doses of dietary nitrate (NO3 -) in overweight and obese older participants. Secondary aims tested dose-dependent changes in cognitive, vascular and pulmonary functions and cerebral blood flow (CBF). METHODS: This was a single blind, four-arm parallel RCT conducted in 60 overweight and obese older participants. Eligible participants were randomized to:1) high NO3 - (140 ml of beetroot juice (BJ) per day, ~800 mg of NO3 -/day), 2) moderate NO3 - (70 ml of BJ per day, ~400 mg of NO3 -/day), 3) low NO3 - (70 ml on alternate days, ~400 mg of NO3 -) or 4) NO3 - depleted (70 ml on alternate days, ~0.001 mg of NO3). Measurements of cognitive, vascular and pulmonary functions and CBF were conducted at baseline and 13-weeks NO3 - intake was assessed by six 24-h recalls, and by measuring NO3 - intake biomarkers. Feasibility was assessed by obtaining qualitative feedback and evaluating trial recruitment, retention, compliance with study visits and measurement protocols. RESULTS: Participant recruitment started in July 2018 and ended in April 2019. Of all the recruitment strategies that were used, advertisement of the study via Facebook generated the highest response rate. Sixty-two participants consented and were enrolled. Overall, characteristics of included participants matched our recruitment criteria. CONCLUSION: The findings from this study provide evidence of the acceptability and feasibility of an intervention investigating the effects of incremental doses of high-nitrate BJ over a prolonged period. TRIAL REGISTRATION: The intervention study was registered with clinical trial ISRCTN registry (ISRCTN14746723) on 27 December 2018.

17.
BMJ Open ; 9(10): e030719, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31676652

RESUMO

OBJECTIVES: To examine knowledge and beliefs about the biological roles of dietary inorganic nitrate in UK-based nutrition professionals, and to explore potential differences by participants' education level. SETTING: An online questionnaire was administered to UK-based nutrition professionals, exploring knowledge and/or beliefs across five areas: (1) health and performance effects of nitrate; (2) current and recommended intake values for nitrate; (3) dietary sources of nitrate; (4) methods of evaluating nitrate intake and (5) nitrate metabolism. PARTICIPANTS: One hundred and twenty-five nutrition professionals. PRIMARY OUTCOME: Knowledge and beliefs about inorganic nitrate. RESULTS: Most nutrition professionals taking part in the survey had previously heard of inorganic nitrate (71%) and perceived it to be primarily beneficial (51%). The majority believed that nitrate consumption can improve sports performance (59%) and reduce blood pressure (54%), but were unsure about effects on cognitive function (71%), kidney function (80%) and cancer risk (70%). Knowledge of dietary sources of nitrate and factors affecting its content in food were generally good (41%-79% of participants providing correct answers). However, most participants were unsure of the average population intake (65%) and the acceptable daily intake (64%) of nitrate. Most participants (65%) recognised at least one compound (ie, nitric oxide or nitrosamines) that is derived from dietary nitrate in the body. Knowledge of nitrate, quantified by a 23-point index created by summing correct responses, was greater in individuals with a PhD (p=0.01; median (IQR)=13 (9-17)) and tended to be better in respondents with a masters degree (p=0.054; 13 (8-15)) compared with undergraduate-level qualifications (10 (2-14)). CONCLUSIONS: UK-based nutrition professionals demonstrated mixed knowledge about the physiology of dietary nitrate, which was better in participants with higher education. More efficient dissemination of current knowledge about inorganic nitrate and its effects on health to nutrition professionals will support them to make more informed recommendations about consumption of this compound.


Assuntos
Atitude do Pessoal de Saúde , Competência Clínica , Escolaridade , Nitratos , Nutricionistas , Adulto , Idoso , Desempenho Atlético , Pressão Sanguínea , Cognição , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recomendações Nutricionais , Inquéritos e Questionários , Reino Unido
18.
Nitric Oxide ; 91: 15-22, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31295558

RESUMO

The nitrate (NO3-)-nitrite (NO2-)-nitric oxide (NO) pathway has received considerable interest in recent years as a potential target for nutritional interventions designed to increase NO production, and elicit therapeutic effects in humans. In particular, studies have evaluated the effects of supplemental dietary NO3-, which serves as a 'substrate' for this pathway, on numerous different health outcomes. One challenge has been to evaluate compliance with the NO3- interventions. A recent advance in this field has been the development of a non-invasive, simple and rapid method to measure nitrite concentrations in saliva using small test salivary strips. In the present study, ten healthy adults were recruited to a randomised, crossover study and received an acute dose of NO3--rich beetroot juice (BJ) after rinsing their mouth with either water or commercially available antibacterial mouthwash. Salivary NO3- and NO2- concentrations were measured at baseline and up to 5 h after BJ consumption using the gold-standard chemiluminescence and a colorimetric Griess assay. In addition, two salivary test strips (Berkeley Test strips, CA, USA) were used to measure NO2-concentrations at the same time points. Five observers read the strips and inter- and intra-observer reliability was measured. The Bland-Altman method was used to provide a visual representation of the agreement between the methods used to evaluate salivary NO3-/NO2-concentration. Sialin concentrations were measured at baseline and up to 5 h after BJ consumption. BJ elevated salivary NO3- and NO2- concentrations when the mouth was rinsed with water (both P < 0.01), as assessed via both chemiluminescence and Griess methods. Rinsing the mouth with antibacterial mouthwash attenuated markedly the increase in NO2- (P < 0.001), while NO3-concentrations were unaffected (P > 0.05). The Intra-Class Coefficients of Correlation (ICC) showed a high inter- and intra-observer reliability (r > 0.8). A significant positive correlation was found between absolute salivary NO2- concentrations measured by strips and Griess and chemiluminescence methods (rho = 0.83 and 0.77, respectively) and also when expressed as changes in salivary NO2- concentrations (rho = 0.80 and 0.79, respectively). Bland Altman analysis indicated a poor agreement for absolute NO2- concentrations between salivary strips and the chemiluminescence and Griess methods. A small significant negative correlation was found between changes in salivary sialin and salivary NO2- concentrations (r = -0.20, P = 0.04). A non-significant positive correlation was observed between the change in salivary sialin and salivary NO3- concentrations (r = 0.18, P = 0.06). This study suggests that commercially available salivary NO2- test strips provide a reasonable surrogate marker for monitoring changes in salivary NO2- concentrations in humans. However, the strips do not provide accurate estimates of absolute NO2- concentrations.


Assuntos
Colorimetria/instrumentação , Antissépticos Bucais/farmacologia , Nitritos/análise , Saliva/química , Adulto , Beta vulgaris/química , Colorimetria/métodos , Estudos Cross-Over , Feminino , Sucos de Frutas e Vegetais , Humanos , Masculino , Microbiota/efeitos dos fármacos , Pessoa de Meia-Idade , Boca/microbiologia , Nitratos/análise , Transportadores de Ânions Orgânicos/metabolismo , Reprodutibilidade dos Testes , Simportadores/metabolismo , Adulto Jovem
19.
Nutr Clin Pract ; 34(6): 922-934, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31347209

RESUMO

BACKGROUND: Our purpose was to assess the accuracy of resting energy expenditure (REE) equations in patients with newly diagnosed stage I-IV non-small cell lung, rectal, colon, renal, or pancreatic cancer. METHODS: In this cross-sectional study, REE was measured using indirect calorimetry and compared with 23 equations. Agreement between measured and predicted REE was assessed via paired t-tests, Bland-Altman analysis, and percent of estimations ≤ 10% of measured values. Accuracy was measured among subgroups of body mass index (BMI), stage (I-III vs IV), and cancer type (lung, rectal, and colon) categories. Fat mass (FM) and fat-free mass (FFM) were assessed using dual x-ray absorptiometry. RESULTS: Among 125 patients, most had lung, colon, or rectal cancer (92%, BMI: 27.5 ± 5.6 kg/m2 , age: 61 ± 11 years, REE: 1629 ± 321 kcal/d). Thirteen (56.5%) equations yielded REE values different than measured (P < 0.05). Limits of agreement were wide for all equations, with Mifflin-St. Jeor equation having the smallest limits of agreement, -21.7% to 11.3% (-394 to 203 kcal/d). Equations with FFM were not more accurate except for one equation (Huang with body composition; bias, limits of agreement: -0.3 ± 11.3% vs without body composition: 2.3 ± 10.1%, P < 0.001). Bias in body composition equations was consistently positively correlated with age and frequently negatively correlated with FM. Bias and limits of agreement were similar among subgroups of patients. CONCLUSION: REE cannot be accurately predicted on an individual level, and bias relates to age and FM.


Assuntos
Metabolismo Basal/fisiologia , Neoplasias/metabolismo , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Antropometria , Composição Corporal/fisiologia , Índice de Massa Corporal , Calorimetria Indireta , Estudos Transversais , Ingestão de Energia , Metabolismo Energético/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Estadiamento de Neoplasias , Neoplasias/patologia , Valor Preditivo dos Testes
20.
Am J Clin Nutr ; 110(4): 938-948, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31204785

RESUMO

BACKGROUND: In Mediterranean countries, adherence to a traditional Mediterranean dietary pattern (MedDiet) is associated with better cognitive function and reduced dementia risk. It is unclear if similar benefits exist in non-Mediterranean regions. OBJECTIVES: The aims of this study were to examine associations between MedDiet adherence and cognitive function in an older UK population and to investigate whether associations differed between individuals with high compared with low cardiovascular disease (CVD) risk. METHODS: We conducted an analysis in 8009 older individuals with dietary data at Health Check 1 (1993-1997) and cognitive function data at Health Check 3 (2006-2011) of the European Prospective Investigation into Cancer and Nutrition-Norfolk (EPIC-Norfolk). Associations were explored between MedDiet adherence and global and domain-specific cognitive test scores and risk of poor cognitive performance in the entire cohort, and when stratified according to CVD risk status. RESULTS: Higher MedDiet adherence defined by the Pyramid MedDiet score was associated with better global cognition (ß ± SE = -0.012 ± 0.002; P < 0.001), verbal episodic memory (ß ± SE = -0.009 ± 0.002; P < 0.001), and simple processing speed (ß ± SE = -0.002 ± 0.001; P = 0.013). Lower risk of poor verbal episodic memory (OR: 0.784; 95% CI: 0.641, 0.959; P = 0.018), complex processing speed (OR: 0.739; 95% CI: 0.601, 0.907; P = 0.004), and prospective memory (OR: 0.841; 95% CI: 0.724, 0.977; P = 0.023) was also observed for the highest compared with the lowest Pyramid MedDiet tertiles. The effect of a 1-point increase in Pyramid score on global cognitive function was equivalent to 1.7 fewer years of cognitive aging. MedDiet adherence defined by the Mediterranean Diet Adherence Screener (MEDAS) score (mapped through the use of both binary and continuous scoring) showed similar, albeit less consistent, associations. In stratified analyses, associations were evident in individuals at higher CVD risk only (P < 0.05). CONCLUSIONS: Higher adherence to the MedDiet is associated with better cognitive function and lower risk of poor cognition in older UK adults. This evidence underpins the development of interventions to enhance MedDiet adherence, particularly in individuals at higher CVD risk, aiming to reduce the risk of age-related cognitive decline in non-Mediterranean populations.


Assuntos
Transtornos Cognitivos/epidemiologia , Transtornos Cognitivos/prevenção & controle , Cognição , Dieta Mediterrânea , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Avaliação Nutricional , Estudos Prospectivos , Reino Unido/epidemiologia
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