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Healthy diet behaviours are important in a globally ageing population, particularly in relation to cardiometabolic and brain health. The Eatwell guide (EWG) reflects the UK government’s recommendations for a healthy and balanced diet. Data from the PREVENT dementia cohort study baseline visit was used in this analysis. Binary and graded EWG scores (BEWG, GEWG) were created from a self-reported Food Frequency Questionnaire. The CAIDE score was included as the primary outcome measure to represent risk for future AD. Secondary outcome measures included cardiometabolic health measures, and brain health measures. Generalised additive models were run in R. A total of 517 participants were included in the analysis, with a mean BEWG score of 4.39 (±1.66) (out of a possible 12 points) and GEWG score of 39.88 (±6.19) (out of a possible 60 points). There was no significant association between either EWG score and the CAIDE (BEWG β: 0.07; p: 0.32; GEWG β: 0.02, p: 0.36) or any measures of brain health. There was a significant association between higher GEWG score and lower systolic and diastolic blood pressure and body mass index (BMI) (systolic β: -0.24, p: 0.03; diastolic β: -0.16, p: 0.01; BMI β: -0.09, p: 0.02). Although not directly associated with the CAIDE score, the EWG dietary pattern may be beneficial for dementia prevention efforts through modification of hypertension and obesity, which are both known risk factors for dementia. Future work could replicate these findings in other UK-based cohorts as well as further development of EWG scoring methodologies.

Refereed/Peer-reviewed Purpose: Reporting guidelines facilitate quality and completeness in research reporting. The CONsolidated Standards Of Reporting Trials (CONSORT) statement is widely applied to dietary and nutrition trials but has no extension specific to nutrition. Evidence suggests poor reporting in nutrition research. The Federation of European Nutrition Societies led an initiative to make recommendations for a nutrition extension to the CONSORT statement towards a more robust reporting of the evidence base. Methods: An international working group was formed of nutrition researchers from 14 institutions in 12 different countries and on five continents. Using meetings over a period of one year, we interrogated the CONSORT statement specifically for its application to report nutrition trials. Results: We provide a total of 28 new nutrition-specific recommendations or emphasised recommendations for the reporting of the introduction (three), methods (twelve), results (five) and discussion (eight). We also added two additional recommendations that were not allocated under the standard CONSORT headings. Conclusion: We identify a need to provide guidance in addition to CONSORT to improve the quality and consistency of the reporting and propose key considerations for further development of formal guidelines for the reporting of nutrition trials. Readers are encouraged to engage in this process, provide comments and conduct specific studies to inform further work on the development of reporting guidelines for nutrition trials.

Consumption of the Mediterranean dietary pattern (MedDiet) is associated with reduced risk of numerous non-communicable diseases. Modulation of the composition and metabolism of the gut microbiota represents a potential mechanism through which the MedDiet elicits these effects. We conducted a systematic literature search (Prospero registration: CRD42020168977) using PubMed, The Cochrane Library, MEDLINE, SPORTDiscuss, Scopus and CINAHL databases for randomized controlled trials (RCTs) and observational studies exploring the impact of a MedDiet on gut microbiota composition (i.e., relative abundance of bacteria or diversity metrics) and metabolites (e.g., short chain fatty acids). Seventeen RCTs and 17 observational studies were eligible for inclusion in this review. Risk of bias across the studies was mixed but mainly identified as low and unclear. Overall, RCTs and observational studies provided no clear evidence of a consistent effect of a MedDiet on composition or metabolism of the gut microbiota. These findings may be related to the diverse methods across studies (e.g., MedDiet classification and analytical techniques), cohort characteristics, and variable quality of studies. Further, well-designed studies are warranted to advance understanding of the potential effects of the MedDiet using more detailed examination of microbiota and microbial metabolites with reference to emerging characteristics of a healthy gut microbiome. This systematic review explored effects of the Mediterranean diet on the composition and metabolism of the gut microbiota in both randomized controlled trials and observational studies. Although there is some evidence from a small number of studies indicated a positive impact of a Mediterranean diet on select microbiota, the findings of this systematic review suggest that this dietary pattern does not consistently alter microbiota composition or metabolism. The lack of a consistent effect could be related to methodological differences between studies, especially differences in the composition of the Mediterranean diet administered.

Contains fulltext : 282473.pdf (Publisher’s version ) (Open Access) Observational studies suggest that nutritional factors have a potential cognitive benefit. However, systematic reviews of randomised trials of dietary and nutritional supplements have reported largely null effects on cognitive outcomes and have highlighted study inconsistencies and other limitations. In this Personal View, the Nutrition for Dementia Prevention Working Group presents what we consider to be limitations in the existing nutrition clinical trials for dementia prevention. On the basis of this evidence, we propose recommendations for incorporating dietary patterns and the use of genetic, and nutrition assessment tools, biomarkers, and novel clinical trial designs to guide future trial developments. Nutrition-based research has unique challenges that could require testing both more personalised interventions in targeted risk subgroups, identified by nutritional and other biomarkers, and large-scale and pragmatic study designs for more generalisable public health interventions across diverse populations.

The use of omega-3 polyunsaturated fatty acid (ω-3 PUFA) supplements is increasingly common among middle-aged and older adults. Users of ω-3 PUFA supplements often report using such supplements to support cognitive health, despite mixed findings reported within the ω-3 PUFA literature. To date, very few studies have explored cognitive effects in distinctly middle-aged (40 to 60 years) adults, and none have examined the acute effects (in the hours following a single dose) on cognitive performance. The current study evaluated whether a single dose of ω-3 PUFA (4020 mg docosahexaenoic acid and 720 mg eicosapentaenoic acid) influences cognitive performance and cardiovascular function in middle-aged males. Cognitive performance and cardiovascular function were assessed before and 3.5–4 h after consumption of a high dose of ω-3 PUFA (DHA + EPA) or placebo, incorporated into a standardized meal (i.e., single serve of Greek yogurt). In this study of middle-aged males, no significant differential treatment effects were observed for cognitive performance. However, a significant reduction in aortic systolic blood pressure (pre-dose to post-dose) was apparent following consumption of the ω-3 PUFA (DHA + EPA) treatment (mean difference = −4.11 mmHg, p = 0.004) but not placebo (mean difference = −1.39 mmHg, p = 0.122). Future replication in a sample comprising females, as well as patients with hypertension, is merited.

The apolipoprotein E4 (APOE4) genotype is predictive of Alzheimer’s disease (AD). The brain is highly enriched with the omega-3 polyunsaturated fatty acid (n3-PUFA), docosahexaenoic acid (DHA). DHA’s metabolism is defective in APOE4 carriers. Flavanol intake can play a role in modulating DHA levels. However, the impact of flavanol co-supplementation with fish oil on brain DHA uptake, status and partitioning, and according to APOE genotype is currently unknown. Here, using a humanised APOE3 and APOE4 targeted replacement transgenic mouse model, the interactive influence of cocoa flavanols (FLAV) and APOE genotype on the blood and subcortical brain PUFA status following the supplementation of a high fat (HF) enriched with DHA from fish oil (FO) was investigated. DHA levels increased in the blood (p < 0.001) and brain (p = 0.001) following supplementation. Compared to APOE3, a higher red blood cell (RBC) DHA (p < 0.001) was evident in APOE4 mice following FO and FLAV supplementation. Although FO did not increase the percentage of brain DHA in APOE4, a 17.1% (p < 0.05) and 20.0% (p < 0.001) higher DHA level in the phosphatidylcholine (PC) fraction in the HF FO and HF FO FLAV groups, and a 14.5% (p < 0.05) higher DHA level in the phosphatidylethanolamine (PE) fraction in the HF FO FLAV group was evident in these animals relative to the HF controls. The addition of FLAV (+/− FO) did not significantly increase the percentage of brain DHA in the group as a whole. However, a higher brain: RBC DHA ratio was evident in APOE3 only (p < 0.05) for HF FLAV versus HF. In conclusion, our data shows only modest effects of FLAV on the brain DHA status, which is limited to APOE3.

Female

With growing and ageing populations, the incidence of dementia is expected to triple globally by 2050. In the absence of effective drugs to treat or reverse the syndrome, dietary approaches which prevent or delay disease onset have considerable population health potential. Prospective epidemiological studies and mechanistic insight from experimental models strongly support a positive effect of a high fish and long chain n-3 fatty acid (EPA and DHA) intake on a range of cognitive outcomes and dementia risk, with effect sizes equivalent to several years of ageing between the highest and lowest consumers. As reviewed here, an effect of EPA and DHA on neuroinflammation and oxylipin production is likely to in part mediate the neurophysiological benefits. However, randomised controlled trials (RCTs) with EPA and DHA supplementation have produced mixed findings. Insight into the likely modulators of response to intervention and factors which should be considered for future RCTs are given. Furthermore, the impact of APOE genotype on disease risk and response to EPA and DHA supplementation is summarised. The prevalence of dementia is several-fold higher in APOE4 females (about 13% Caucasian populations) relative to the general population, who are emerging as a subgroup who may particularly benefit from DHA intervention, prior to the development of significant pathology.

The term Mediterranean diet first appeared in the late 1940s (1). It is described by UNESCO as ‘a set of skills, knowledge, practices and traditions ranging from the landscape to the table, including the crops, harvesting, fishing, conservation, processing, preparation and, particularly, consumption of food’. A Mediterranean dietary pattern (MDP) varies in composition between the 21 countries which make up the Mediterranean region but is typically characterised by high intakes of minimally processed plant-based foods such as fruits, vegetables, nuts, seeds, legumes and wholegrains. Extra virgin olive oil is the main culinary fat, with a moderate intake of dairy products, and a variety of herbs and spices used as condiments, rather than salt. Fish/seafood is typically consumed two-three times per week. Red and processed meat, and discretionary foods including sugar or honey sweetened food and drink are consumed in low amounts. Wine, and in particular red wine, is consumed in moderation and with meals. Although in many ways analogous to other global healthy plant based dietary patterns, it is the high intakes of olive oil, nuts and red wine, which makes the MDP unique. The MDP has been used as a benchmark for comparison with other dietary patterns (2) and has influenced the dietary guidelines for non-Mediterranean countries like the USA, Canada and Australia. Refereed/Peer-reviewed

Although the long-term effects of a Mediterranean-style dietary pattern (MDP) on cognition and overall mental well-being have been consistently described, the short-term effects of the MDP on cognitive performance, mood and anxiety have not been as widely reviewed. Therefore, the aims of this systematic review were to synthesise the evidence from randomised controlled trials (RCT), to examine whether a MDP can alter cognition and overall mental well-being in the short-term (up to 10 d). This will also be used to identify research gaps and to inform the design of future acute RCT in the area. Ovid Embase, Ovid MEDLINE and Web of Science Core Collection were searched from inception to 8 December 2020. The data were synthesised narratively with no quantitative synthesis. The detailed protocol is available on PROSPERO, with the registration number CRD42021221085. A total of 3002 studies were initially identified. After the deduplication and screening stages, four studies (three articles and one conference proceeding) were eligible to be included. Despite the very limited data obtained, the literature suggests that a MDP can improve cognition and mood in the short-term. Specifically, improvements in attention, alertness and contentment were consistently reported. A MDP appears as a promising strategy to improve short-term cognitive and mental health. A limitation of this review is the small number of studies identified; therefore, future studies are required to confirm these initial novel findings and to provide granularity as to which domains are most responsive and in which population subgroups.

With growing and ageing populations, the incidence of dementia is expected to triple globally by 2050. In the absence of effective drugs to treat or reverse the syndrome, dietary approaches which prevent or delay disease onset have considerable population health potential. Prospective epidemiological studies and mechanistic insight from experimental models strongly support a positive effect of a high fish and long chain

There is a drive in the UK to harness findings from novel fundamental and efficacy nutritional research and, through inter-disciplinary and multi-agency collaborations, to improve eating behaviour for the benefit of population health. This report summarises the progress made during the Medical Research Council-funded Hot Topic workshop on the planning for a potential UK-wide nutrition primary prevention randomised controlled trial with incident disease as the study endpoint: the UK Nutrition and Healthy Life Expectancy (NuLifE) Trial. Through two workshops, along with online discussions and a systematic evidence synthesis, over 40 experts from a range of disciplines came together over 6 months. The workshop reached a consensus and delivered a three-stage plan with the ultimate ambitious aim of providing effective eating behaviour change strategies to address the growing inequalities in the UK and contribute to both a reduced risk of prevalent diet-related chronic disease and an increase in healthy life expectancy.

Ageing is a multifactorial process associated with reduced function and increased risk of morbidity and mortality. Recently, nine cellular and molecular hallmarks of ageing have been identified, which characterise the ageing process and, collectively, may be key determinants of the ageing trajectory. These include genomic instability, telomere attrition, epigenetic alterations, loss of proteostasis, deregulated nutrient sensing, mitochondrial dysfunction, cellular senescence, stem cell exhaustion, and altered intercellular communication. Healthier dietary patterns reduce the risk of age-related diseases and increase longevity and may influence positively one or more of these hallmarks. The Mediterranean dietary pattern (MedDiet) is a plant-based eating pattern that was typical of countries such as Greece, Spain, and Italy pre-globalisation of the food system and which is associated with better health during ageing. Here we review the potential effects of a MedDiet on each of the nine hallmarks of ageing, and provide evidence that the MedDiet as a whole, or individual elements of this dietary pattern, may influence each hallmark positively – effects which may contribute to the beneficial effects of this dietary pattern on age-related disease risk and longevity. We also highlight potential avenues for future research.

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.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.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.Higher MedDiet adherence defined by the Pyramid MedDiet score was associated with better global cognition (β ± SE = -0.012 ± 0.002; P 0.001), verbal episodic memory (β ± SE = -0.009 ± 0.002; P 0.001), and simple processing speed (β ± 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).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.

BACKGROUND: Hip fracture represents a substantial acute inflammatory trauma, which may constitute a significant insult to the degenerating brain. Research suggests that an injury of this kind can affect memory and thinking in the future but it is unclear whether, and how, inflammatory trauma injures the brain. The impact of Acute SystematiC inflammation upon cerebRospinal fluId and blood BiomarkErs of brain inflammation and injury in Dementia: a study in acute hip fracture patients (ASCRIBED) explores this relationship, to understand the effect of inflammation on the progression of dementia.METHODS: This protocol describes a multi-centre sample collection observational study. The study utilises the unique opportunity provided by hip fracture operations undertaken via spinal anaesthesia to collect cerebrospinal fluid (CSF) and blood, to investigate the impact of acute brain inflammation caused by hip fracture on the exacerbation of dementia. We will recruit 200 hip fracture patients with a diagnosis or evidence of dementia; and 200 hip fracture patients without dementia. We will also recruit 'Suitable informants', individuals in regular contact with the patient, to provide further proxy evidence of a patient's potential cognitive decline. We will compare these 400 samples with existing CSF and blood samples from a cohort of dementia patients who had not experienced a systemic inflammatory response due to injury. This will provide a comparison between patients with and without dementia who are suffering a systemic inflammatory response; with stable patients living with dementia.DISCUSSION: We will test the hypothesis that hip fracture patients living with dementia show elevated markers of brain inflammation, as well as neuronal injury and Alzheimer-related plaque pathology, in comparison to (1) stable patients living with dementia and (2) hip fracture patients without dementia, as measured by biomarkers in CSF and blood. The findings will address the hypothesis that systemic inflammatory events can exacerbate underlying dementia and inform the search for new treatments targeting inflammation in dementia.TRIAL REGISTRATION: ISRCTN43803769 . Registered 11 May 2017.

An apolipoprotein E (APOE) 4 genotype is the most important, common genetic determinant for Alzheimer disease (AD), and female APOE4 carriers present with an increased risk compared with males. The study quantified cortical and hippocampal fatty acid and phospholipid profiles along with select eicosapentaenoic acid (EPA)- and docosahexaenoic acid (DHA)-derived specialized proresolving mediators (SPMs) in 2-, 9-, and 18-mo-old APOE3 and APOE4 male and female mice. A 10% lower cortical DHA was evident in APOE4 females at 18 mo compared with 2 mo, with no significant decrease in APOE3 or APOE4 males. This decrease was associated with a reduction in DHA-phosphatidylethanolamine. Older APOE4 females had a 15% higher oleic acid content compared with young mice. Although no sex*APOE genotype interactions were observed for SPMs expressed as a ratio of their parent compound, higher cortical 18R/S-hydroxy-5Z,8Z,11Z,14Z,16E-EPA, resolvin D3, protectin D1, 10S,17S-dihydroxy-4Z,7Z,11E,13E,15Z,19Z-DHA (10S,17S-diHDHA), maresin 1, 17S-hydroxy-4Z,7Z,10Z,13Z,15E,19Z-DHA, and 14S-hydroxy-4Z,7Z,10Z,12E,16Z,19Z-DHA were evident in females, and lower cortical 17R-resolvin D1, 10S,17S-diHDHA, and 18-HEPE in APOE4. Our findings show a strong association between age, female sex, and an APOE4 genotype, with decreased cortical DHA and a number of SPMs, which together may contribute to the development of cognitive decline and AD pathology.-Martinsen, A., Tejera, N., Vauzour, D., Harden, G., Dick, J., Shinde, S., Barden, A., Mori, T. A., Minihane, A. M. Altered SPMs and age-associated decrease in brain DHA in APOE4 female mice.

Apolipoprotein E (APOE) genotype is the strongest prevalent genetic risk factor for Alzheimer's disease (AD). Numerous studies have provided insights into the pathologic mechanisms. However, a comprehensive understanding of the impact of APOE genotype on microflora speciation and metabolism is completely lacking. In this study, we investigated the association between APOE genotype and the gut microbiome composition in human and APOE-targeted replacement (TR) transgenic mice. Fecal microbiota amplicon sequencing from matched individuals with different APOE genotypes revealed no significant differences in overall microbiota diversity in group-aggregated human APOE genotypes. However, several bacterial taxa showed significantly different relative abundance between APOE genotypes. Notably, we detected an association of Prevotellaceae and Ruminococcaceae and several butyrate-producing genera abundances with APOE genotypes. These findings were confirmed by comparing the gut microbiota of APOE-TR mice. Furthermore, metabolomic analysis of murine fecal water detected significant differences in microbe-associated amino acids and short-chain fatty acids between APOE genotypes. Together, these findings indicate that APOE genotype is associated with specific gut microbiome profiles in both humans and APOE-TR mice. This suggests that the gut microbiome is worth further investigation as a potential target to mitigate the deleterious impact of the APOE4 allele on cognitive decline and the prevention of AD.-Tran, T. T. T., Corsini, S., Kellingray, L., Hegarty, C., Le Gall, G., Narbad, A., Muller, M., Tejera, N., O'Toole, P. W., Minihane, A.-M., Vauzour, D. APOE genotype influences the gut microbiome structure and function in humans and mice: relevance for Alzheimer's disease pathophysiology.

Background: Using a genome-wide association study (GWAS) approach, our group previously computed a genetic risk score (GRS) from single nucleotide polymorphisms (SNPs) of 10 loci that affect the plasma triglyceride (TG) response to an omega-3 (n–3) fatty acid (FA) supplementation. Objectives: The objective was to compute a novel and more refined GRS using fine mapping to include a large number of genetic variants. Methods: A total of 208 participants of the Fatty Acid Sensor (FAS) Study received 5 g fish oil/d, containing 1.9–2.2 g eicosapentaenoic acid and 1.1 g docosahexanoic acid, for 6 wk. Plasma TG concentrations were measured before and after supplementation. Dense genotyping and genotype imputation were used to refine mapping around GWAS hits. A GRS was computed by summing the number of at-risk alleles of tagging SNPs. Analyses were replicated in samples of the FINGEN study. Results: A total of 31 tagging SNPs associated with the TG response were used for GRS calculation in the FAS study. In a general linear model adjusted for age, sex, and body mass index, the GRS explained 49.73% of TG response variance (P < 0.0001). Nonresponders to the n–3 FA supplementation had a higher GRS than did responders. In the FINGEN replication study, the GRS explained 3.67% of TG response variance (P = 0.0006). Conclusions: Fine mapping proved to be effective to refine the previous GRS. Carrying increasing numbers of at-risk alleles of 31 SNPs confers a higher risk of being nonresponsive to n–3 FAs. The genetic profile therefore appears to be an important determinant of the plasma TG response to an n–3 FA supplementation and could be used to target those most likely to gain clinical benefit. This trial was registered at http://www.clinicaltrials.gov as NCT01343342.

The impact of sex and menopausal status in Alzheimer’s disease remains understudied despite increasing evidence of greater female risk, particularly in APOE4 carriers. Utilizing female APOE‐TR mice maintained on a high‐fat diet background we induced ovarian failure through repeated VCD injections, to mimic human menopause. At 12 months of age, recognition memory and spatial memory were assessed using object recognition, Y‐maze spontaneous alternation, and Barnes maze. A VCD*genotype interaction reduced the recognition memory (P < .05), with APOE4 VCD‐treated animals unable to distinguish between novel and familiar objects. APOE4 mice displayed an additional 37% and 12% reduction in Barnes (P < .01) and Y‐maze (P < .01) performance, indicative of genotype‐specific spatial memory impairment. Molecular analysis indicated both VCD and genotype‐related deficits in synaptic plasticity with BDNF, Akt, mTOR, and ERK signaling compromised. Subsequent reductions in the transcription factors Creb1 and Atf4 were also evident. Furthermore, the VCD*genotype interaction specifically diminished Ephb2 expression, while Fos, and Cnr1 expression reduced as a consequence of APOE4 genotype. Brain DHA levels were 13% lower in VCD‐treated animals independent of genotype. Consistent with this, we detected alterations in the expression of the DHA transporters Acsl6 and Fatp4. Our results indicate that the combination of ovarian failure and APOE4 leads to an exacerbation of cognitive and neurological deficits.

OBJECTIVES: To provide baseline cohort descriptives and assess change in health behaviours since the UK COVID-19 lockdown. DESIGN: A prospective cohort (N = 1,044) of people recruited online, purposively targeting vulnerable populations. METHODS: After a baseline survey (April 2020), participants completed 3 months of daily ecological momentary assessments (EMA). Dietary, physical activity, alcohol, smoking, vaping and substance use behaviours collected retrospectively for the pre-COVID-19 period were compared with daily EMA surveys over the first 30 days during early lockdown. Predictors of behaviour change were assessed using multivariable regression models. RESULTS: 30% of the cohort had a COVID-19 at risk health condition, 37% were classed as deprived and 6% self-reported a mental health condition. Relative to pre-pandemic levels, participants ate almost one portion of fruit and vegetables less per day (vegetables mean difference -0.33, 95% CI -0.40, -0.25; fruit -0.57, 95% CI -0.64, -0.50), but showed no change in high sugar portions per day (-0.03, 95% CI -0.12, 0.06). Participants spent half a day less per week doing ≥30 min of moderate to vigorous physical activity (-0.57, 95% CI -0.73, -0.40) but slightly increased days of strength training (0.21, 95% CI 0.09, 0.34), increased alcohol intake (AUDIT-C score change 0.25, 95% CI 0.13, 0.37), though did not change smoking, vaping or substance use behaviour. Worsening health behaviour change was associated with being younger, female and higher body mass index. CONCLUSIONS: The cohort reported worsening health behaviours during early lockdown. Longer term changes will be investigated using further waves of data collection.

Docosahexaenoic acid is the main long-chain omega-3 polyunsaturated fatty acids in the brain and accounts for 30−40% of fatty acids in the grey matter of the human cortex. Although the influence of docosahexaenoic acid on memory function is widely researched, its association with brain volumes is under investigated and its association with spatial navigation is virtually unknown. This is despite the fact that spatial navigation deficits are a new cognitive fingerprint for symptomatic and asymptomatic Alzheimer’s disease. We investigated the cross-sectional relationship between docosahexaenoic acid levels and the major structural and cognitive markers of preclinical Alzheimer’s disease, namely hippocampal volume, entorhinal volume and spatial navigation ability. Fifty-three cognitively normal adults underwent volumetric magnetic resonance imaging, measurements of serum docosahexaenoic acid (DHA, including lysophosphatidylcholine DHA) and APOE ε4 genotyping. Relative regional brain volumes were calculated and linear regression models were fitted to examine DHA associations with brain volume. APOE genotype modulated serum DHA associations with entorhinal cortex volume and hippocampal volume. Linear models showed that greater serum DHA was associated with increased entorhinal cortex volume, but not hippocampal volume, in non APOΕ ε4 carriers. APOE also interacted with serum lysophosphatidylcholine DHA to predict hippocampal volume. After testing interactions between DHA and APOE on brain volume, we investigated whether DHA and APOE interact to predict spatial navigation performance on a novel virtual reality diagnostic test for Alzheimer’s disease in an independent population of APOE genotyped adults (n = 46). APOE genotype modulated DHA associations with spatial navigation performance, showing that DHA was inversely associated with path integration in APOE ε4 carriers only. This exploratory analysis suggests that interventions aiming to increase DHA blood levels to protect against cognitive decline should consider APOE ε4 carrier status. Future work should focus on replicating our initial findings and establishing whether a specific dose of supplementary DHA, at a particular time in the preclinical disease course can have a positive impact on Alzheimer’s disease progression in APOE ε4 carriers., Docosahexaenoic acid’s neuroprotective effect may be concentrated in the entorhinal cortex and hippocampus. Here, we show that docosahexaenoic acid’s association with entorhinal volume and spatial navigation ability is modulated by the APOE genotype, with non-significant or inverse associations found in APOE ε4 carriers who are genetically-at-risk of Alzheimer’s disease., Graphical Abstract Graphical Abstract

Objective: To conduct a systematic review and meta-analysis investigating effects of MedDiet on blood pressure in randomised controlled trials (RCTs) and associations of MedDiet with risk of hypertension in observational studies. Methods: PubMed, The Cochrane Library and EBSCOhost were searched from inception until January 2020 for studies that met the following criteria: 1) participants aged ≥18 years, 2) RCTs investigating effects of a MedDiet versus control on BP, 3) Observational studies exploring associations between MedDiet adherence and risk of hypertension. Random-effects meta-analyses were conducted. Meta-regression and subgroup analyses were performed for RCTs to identify potential effect moderators. Results: Nineteen RCTs reporting data on 4137 participants and 16 observational studies reporting data on 59,001 participants were included in the meta-analysis. MedDiet interventions reduced systolic and diastolic BP by a mean -1.4 mmHg (95% CI: -2.40 to -0.39 mmHg, p=0.007, I2=53.5%, Q=44.7, τ2=1.65, df=19) and -1.5 mmHg (95% CI: -2.74 to -0.32 mmHg, p=0.013, I2=71.5%, Q=51.6, τ2=4.72, df=19) versus control, respectively. Meta-regression revealed that longer study duration and higher baseline systolic BP was associated with a greater decrease in BP, in response to a MedDiet (p

IntroductionDementia 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.MethodsOne 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.DiscussionThis 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 disseminationThe 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 detailsClinicalTrials.gov NCT03673722.

It is unclear what non-pharmacological interventions to prevent cognitive decline should comprise. We systematically reviewed lifestyle and psychosocial interventions that aimed to reduce cognitive decline in healthy people aged 50+, and people of any age with Subjective Cognitive Decline or Mild Cognitive Impairment. We narratively synthesised evidence, prioritising results from studies rated as at lower Risk of Bias (ROB) and assigning Centre for Evidence Based Medicine grades. We included 64 papers, describing: psychosocial (n = 12), multi-domain (n = 10), exercise (n = 36), and dietary (n = 6) interventions. We found Grade A evidence that over 4+ months: aerobic exercise twice weekly had a moderate effect on global cognition in people with/ without MCI; and interventions that integrate cognitive and motor challenges (e.g. dance, dumb bell training) had small to moderate effects on memory or global cognition in people with MCI. We found Grade B evidence that 4+ months of creative art or story-telling groups in people with MCI; 6 months of resistance training in people with MCI and a two-year, dietary, exercise, cognitive training and social intervention in people with or without MCI had small, positive effects on global cognition. Effects for some intervention remained up to a year beyond facilitated sessions.

● Global prevalence of dementia is predicted to almost triple by 2050 ● There are currently no effective drugs to prevent or treat dementia ● Improved eating behaviour holds significant potential to reduce the risk and population prevalence ● Owing to its multifactorial aetiology, multiple dietary components which target several physiological pathways and risk factors simultaneously are needed. Therefore dietary patterns and foods (rather than single dietary components), hold the most promise to meaningfully improve cognition in the medium term ● Randomised controlled trials with robust validated cognitive outcomes or, ideally, change in dementia or mild cognitive impairment incidence are needed in order to support the prospective cohort evidence, establish efficacy and effect size, and inform public health policy

With an ageing global population, there is an urgent need to identify effective strategies to maintain brain health across the life course and therein minimise the risk of age‐related neurodegenerative disorders reaching a severe stage which may manifest as dementia. An increasing body of evidence indicates that nutrition is a modifiable lifestyle factor that can promote healthy brain ageing and reduce dementia risk. However, at present, little is known about which dietary patterns, foods and food bioactives influence brain function during ageing, and more research is required to identify at‐risk individuals and population subgroups who are most likely to benefit from future nutritional intervention intended to promote healthier brain ageing. This article introduces the newly established Medical Research Council‐funded NuBrain consortium, the vision of which is to provide a step change in research in the area by developing novel approaches and techniques to further understand the complex interactions between diet and brain health and how we can support appropriate behaviour changes in the population. NuBrain will form a new, sustainable and internationally field‐leading research consortium with multidisciplinary and complementary areas of expertise to address the fundamental research challenges in this area.

The Virtual Supermarket Task (VST) and Sea Hero Quest detect high-genetic-risk Alzheimer`s disease (AD). We aimed to determine their test-retest reliability in a preclinical AD population. Over two time points, separated by an 18-month period, 59 cognitively healthy individuals underwent a neuropsychological and spatial navigation assessment. At baseline, participants were classified as low-genetic-risk of AD or high-genetic-risk of AD. We calculated two-way mixed effects intraclass correlation coefficients (ICC) for task parameters and used repeated measures ANOVAS to determine whether genetic risk or sex contributed to test-retest variability. The egocentric parameter of the VST measure showed the highest test-retest reliability (ICC = .72), followed by the SHQ distance travelled parameter (ICC = .50). Post hoc longitudinal analysis showed that boundary-based navigation predicts worsening episodic memory concerns in high-risk (F = 5.01, P = 0.03), but in not low-risk, AD candidates. The VST and the Sea Hero Quest produced parameters with acceptable test-retest reliability. Further research in larger sample sizes is desirable.

An apolipoprotein E ε4 (APOE-ε4) genotype is the strongest common genetic determinant of Alzheimer's disease (AD). The pleiotropic nature of apolipoprotein E has made elucidation of the aetiological basis difficult to establish, which is further complicated by the fact that the penetrance of the APOE-ε4 allele is modulated by sex, age, and nutrition. A greater metabolic consequence of the APOE-ε4 allele is likely to contribute to the fact that two-thirds of AD patients are female. A higher tissue status of the marine n-3 fatty acid docosahexaenoic acid (DHA) is associated with a lower AD risk. However, APOE-ε4 carriers appear less sensitive to the neurocognitive benefits, which may be due to defective blood-brain barrier transport of DHA exacerbated by aging and possibly sex. This suggests higher DHA requirements in this large population subgroup. This narrative review will consider the influence of sex and DHA in modulating APOE-ε4-mediated AD risk.

Diet and physical activity play key roles in maintaining health and preventing or delaying disease. The global prevalence of dementia, an umbrella term describing a set of symptoms which affect cognitive function, is set to rise dramatically by 2050, with current drug treatments inadequate. Diet and physical activity are modifiable factors in dementia, influencing both disease risk and pathophysiology. It has been known since the 1950s that a Mediterranean diet has positive health benefits. Over the past 25 years, a causal link has been shown between consumption of a Mediterranean diet and decreased risk of cardiovascular disease, particularly in Mediterranean countries. There have also been indications that a Mediterranean diet and increased physical activity can improve cognitive health and delay the onset of dementia. However, causative demonstrations of these effects, as well as the feasibility of implementing such lifestyle changes in a non‐Mediterranean population, are lacking. The new MedEx‐UK programme will attempt to address both these points.

n-3 Fatty acids are associated with better cardiovascular and cognitive health. However, the concentration of EPA, DPA and DHA in different plasma lipid pools differs and factors influencing this heterogeneity are poorly understood. Our aim was to evaluate the association of oily fish intake, sex, age, BMI andAPOEgenotype with concentrations of EPA, DPA and DHA in plasma phosphatidylcholine (PC), NEFA, cholesteryl esters (CE) and TAG. Healthy adults (148 male, 158 female, age 20–71 years) were recruited according toAPOEgenotype, sex and age. The fatty acid composition was determined by GC. Oily fish intake was positively associated with EPA in PC, CE and TAG, DPA in TAG, and DHA in all fractions (P≤0·008). There was a positive association between age and EPA in PC, CE and TAG, DPA in NEFA and CE, and DHA in PC and CE (P≤0·034). DPA was higher in TAG in males than females (PPAPOEgenotype×sex interactions were observed: theAPOE4 allele associated with higher EPA in males (P=0·002), and there was also evidence for higher DPA and DHA (P≤0·032). In conclusion, EPA, DPA and DHA in plasma lipids are associated with oily fish intake, sex, age, BMI andAPOEgenotype. Such insights may be used to better understand the link between plasma fatty acid profiles and dietary exposure and may influence intake recommendations across population subgroups.

At a population level, there is growing evidence of the beneficial effects of dietary flavonoids on health. However, there is extensive heterogeneity in the response to increased intake, which is likely mediated via wide interindividual variability in flavonoid absorption and metabolism. Flavonoids are extensively metabolized by phase I and phase II metabolism (which occur predominantly in the gastrointestinal tract and liver) and colonic microbial metabolism. A number of factors, including age, sex, and genotype, may affect these metabolic processes. In addition, food composition and flavonoid source are likely to affect bioavailability, and emerging data suggest a critical role for the microbiome. This review will focus on the current knowledge for the main subclasses of flavonoids, including anthocyanins, flavonols, flavan-3-ols, and flavanones, for which there is growing evidence from prospective studies of beneficial effects on health. The identification of key factors that govern metabolism and an understanding of how the differential capacity to metabolize these bioactive compounds affect health outcomes will help establish how to optimize intakes of flavonoids for health benefits and in specific subgroups. We identify research areas that need to be addressed to further understand important determinants of flavonoid bioavailability and metabolism and to advance the knowledge base that is required to move toward the development of dietary guidelines and recommendations for flavonoids and flavonoid-rich foods.

The workshop 'Nutrition for the Ageing Brain: Towards Evidence of an Optimal Diet' was organized with funds from the ILSI Europe Nutrition and Mental Performance Task Force. Industry members of this task force are listed on the ILSI Europe website at www.ilsi.eu. For further information about ILSI Europe, please email or call +32 2 771 00 14. This review was prepared taken into account the presentations at the workshop mentioned in the abstract and was conducted by an expert group of ILSI Europe. This publication was coordinated by Mr Jeroen Schuermans, Scientific Project Manager at ILSI Europe during the proceedings process. The authors would like to acknowledge Ms Catherine Collins, Ms Lilou van Lieshout and Dr Lucie Geurts for the finalisation and submission of this manuscript; As people age they become increasingly susceptible to chronic and extremely debilitating brain diseases. The precise cause of the neuronal degeneration underlying these disorders, and indeed normal brain ageing remains however elusive. Considering the limits of existing preventive methods, there is a desire to develop effective and safe strategies. Growing preclinical and clinical research in healthy individuals or at the early stage of cognitive decline has demonstrated the beneficial impact of nutrition on cognitive functions. 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). The latest scientific advances specific to how dietary nutrients and non-nutrient may affect cognitive ageing are presented. Furthermore, several key points related to mechanisms contributing to brain ageing, pathological conditions affecting brain function, and brain biomarkers are also discussed. Overall, findings are inconsistent and fragmented and more research is warranted to determine the underlying mechanisms and to establish dose-response relationships for optimal brain maintenance in different population subgroups. Such approaches are likely to provide the necessary evidence to develop research portfolios that will inform about new dietary recommendations on how to prevent cognitive decline

Prospective observational studies support the use of long-chain omega-3 polyunsaturated fatty acids (PUFAs) in the primary prevention of atherosclerotic cardiovascular disease; however, randomised controlled trials, have often reported neutral findings. There is a long history of debate about the potential harmful effects of a high intake of omega-6 PUFAs, although this idea is not supported by prospective observational studies or randomised controlled trials. Health effects of PUFAs might be influenced by Δ-5 and Δ-6 desaturases, the key enzymes in the metabolism of PUFAs. The activity of these enzymes and modulation by variants in encoding genes (FADS1-2-3 gene cluster) are linked to several cardiometabolic traits. This Review will further consider non-genetic determinants of desaturase activity, which have the potential to modify the availability of PUFAs to tissues. Finally, we discuss the consequences of altered desaturase activity in the context of PUFA intake, that is, gene-diet interactions and their clinical and public health implications.

Navigation processes that are selectively mediated by functional activity in the entorhinal cortex may be a marker of preclinical Alzheimer's disease (AD). Here, we tested if a short path integration paradigm can detect the strongest genetic-risk phenotype of AD in large sample of apolipoprotein E (APOE)-genotyped individuals. We also examined the associations between APOE-mediated navigation process, subjective cognitive decline, and rest-stating network connectivity. Navigation discrepancies classified 77% the APOE-genotyped cohort into their respective low-risk ε3ε3 and high-risk ε3ε4 categories. When connectivity strength between entorhinal and the posterior cingulate cortices (also a functional correlate of strongest APOE-dependant behavioral characteristics) was considered, this classification accuracy increased to 85%. Our findings present a whole picture of at-genetic-risk AD, including select impairment in path integration, self-report cognitive decline, and altered network activity that is reminiscent of the pathological spread of preclinical AD disease. These findings may have important implications for the early detection of AD.

BACKGROUND: The endothelium plays a key role in the maintenance of vascular health and represents a potential physiological target for dietary and other lifestyle interventions designed to reduce the risk of cardiovascular diseases (CVD) including stroke or coronary heart disease. OBJECTIVE: To conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) investigating the effects of the Mediterranean dietary pattern (MedDiet) on endothelial function. METHODS: Medline, Embase, and Scopus databases were searched from inception until January 2019 for studies that met the following criteria: 1) RCTs including adult participants, 2) interventions promoting the MedDiet, 3) inclusion of a control group, and 4) measurements of endothelial function. A random-effects meta-analysis was conducted. Metaregression and subgroup analyses were performed to identify whether effects were modified by health status (i.e., healthy participants versus participants with existing comorbidities), type of intervention (i.e., MedDiet alone or with a cointervention), study duration, study design (i.e., parallel or crossover), BMI, and age of participants. RESULTS: Fourteen articles reporting data for 1930 participants were included in the meta-analysis. Study duration ranged from 4 wk to 2.3 y. We observed a beneficial effect of the MedDiet on endothelial function [standardized mean difference (SMD): 0.35; 95% CI: 0.17, 0.53; P 0.05). CONCLUSIONS: MedDiet interventions improve endothelial function in adults, suggesting that the protective effects of the MedDiet are evident at early stages of the atherosclerotic process with important implications for the early prevention of CVD. This study has the PROSPERO registration number: CRD42018106188.

Navigation processes mediated selectively by the entorhinal cortex (EC) may be impaired in individuals with suspected preclinical Alzheimer’s disease (AD), but the clinical utility of navigation tests to detect such impairments remains to be established. In a sample of 64 individuals (32 e3e3 and 32 e3e4), we tested whether an existing paradigm, the Virtual Supermarket Test (VST), can reliably detect the presence or absence of the APOE e4 allele which accelerates amyloid plaque deposition in the brain. The present study assessed four major navigational processes that are subserved by functionally specialised cell groups located in AD vulnerable regions including the EC and examined the relationship between navigation process and regional functional connectivity (FC) given FC is a marker early AD-related tau seeding. While heading direction and spatial memory were unaffected by at-risk AD, clear altered navigational strategies following path integration were found on the VST in the e3e4 group. The APOE-sensitive VST measure correctly classified 77% of the APOE cohort. Including resting-state FC between the EC and the posterior cingulate cortex, a correlate of the path integration deficit in the APOE e4 group, the classification model increased the accuracy to 85%. Our findings show that at-genetic-risk AD selectively impairs path integration and biases self-reported spatial locations away from the centre and towards the boundary of a virtual environment. Importantly, this impairment is associated with reduced FC between the EC and the posterior cingulate cortex, which in turn informs the neurobiological mechanisms of at-genetic-risk of AD.

Background: Observational studies indicate that approximately a third of dementia cases are attributable to modifiable cardiometabolic, physical and mental health, and social and lifestyle risk factors. There is evidence that intensive behaviour change interventions targeting these factors can reduce cognitive decline. (Figure presented.) Our planned intervention [Colour figure can be viewed at wileyonlinelibrary.com]. Methods and analysis: We will design and test a low intensity, secondary dementia-prevention programme (Active Prevention in People at risk of dementia: Lifestyle, bEhaviour change and Technology to REducE cognitive and functional decline, “APPLE-Tree”) to slow cognitive decline in people with subjective cognitive decline with or without objective cognitive impairment. We will embed our work within social science research to understand how dementia prevention is currently delivered and structured. We will carry out systematic reviews and around 50 qualitative interviews with stakeholders, using findings to coproduce the APPLE-Tree intervention. We plan a 10-session group intervention, involving personalised goal-setting, with individual sessions for those unable or unwilling to attend groups, delivered by psychology assistants who will be trained and supervised by clinical psychologists. The coproduction group (including public and patient involvement [PPI], academic and clinical/third-sector professional representatives) will use the Behaviour Change Wheel theoretical framework to develop it. We will recruit and randomly allocate 704 participants, 1:1 to the intervention: informational control group. This sample size is sufficient to detect a between-group difference at 2 years of 0.15 on the primary outcome (cognition: modified neuropsychological test battery; 90% power, 5% significance, effect size 0.25, SD 0.6). Dissemination: We will work with Public Health England and third-sector partners to produce an effective national implementation approach, so that if our intervention works, it is used in practice.