The effect of increased fruit and vegetable consumption on blood pressure and lipids: a pooled analysis of six randomised controlled fruit and vegetable intervention trials.

BACKGROUND: Increasing fruit and vegetable (FV) consumption is associated with reduced cardiovascular disease risk in observational studies but with little evidence from randomised controlled trials (RCTs). The impact of concurrent pharmacological therapy is unknown. OBJECTIVE: To pool data from six RCTs to examine the effect of increasing FV intake on blood pressure (BP) and lipid profile, also exploring whether effects differed by medication use. DESIGN: Across trials, dietary intake was assessed by diet diaries or histories, lipids by routine biochemical methods and BP by automated monitors. Linear regression provided an estimate of the change in lipid profile or BP associated with a one portion increase in self-reported daily FV intake, with interaction terms fitted for medication use. RESULTS: The pooled sample included a total of 554 participants (308 males and 246 females). Meta-analysis of regression coefficients revealed no significant change in either systolic or diastolic BP per portion FV increase, although there was significant heterogeneity across trials for systolic BP (I2 = 73%). Neither adjusting for change in body mass index, nor analysis according to use of anti-hypertensive medication altered the relationship. There was no significant change in lipid profile per portion FV increase, although there was a significant reduction in total cholesterol among those not on lipid-lowering therapy (P < 0.05 after Bonferroni correction). CONCLUSION: Pooled analysis of six individual FV trials showed no impact of increasing intake on BP or lipids, but there was a total cholesterol-lowering effect in those not on lipid-lowering therapy.

Behaviour Change Techniques in Computerized Cognitive Training for Cognitively Healthy Older Adults: A Systematic Review.

We aimed to describe behaviour change techniques (BCT) used in trials evaluating computerised cognitive training (CCT) in cognitively healthy older adults, and explore whether BCTs are associated with improved adherence and efficacy. The 90 papers included in a recent meta-analysis were reviewed for information about adherence and use of BCTs in accordance with the Behaviour Change Taxonomy. Studies using a specific BCT were compared with studies not using that BCT on efficacy (difference in Hedges' g [Δg]) using three level meta-regression models and on median adherence using the Wilcoxon test. The median number of BCTs per study was 3 (interquartile range [IQR] = 2-5). 'Feedback on behaviour' (if provided by a person; Δg = -0.19, 95% confidence interval [CI] = -0.31;-0.07) and 'non-specific reward' (Δg = -0.19, CI = -0.34;-0.05) were associated with lower efficacy. Certain BCTs that involve personal contact may be beneficial, although none were statistically significantly associated with greater efficacy. The median percentage of adherence was 90% (IQR = 81-95). Adherence was higher in studies using the BCT 'self-monitoring of behaviour' and lower in studies using the BCT 'graded tasks' than studies not using these BCTs (p < 0.001). These findings provide first evidence that BCTs can influence both adherence to and efficacy of CCT programs in cognitively healthy older adults.

A qualitative study to inform adaptations to a brain health intervention for older adults with type 2 diabetes living in rural regions of Ireland.

AIMS: Type 2 diabetes is a risk factor for late-life dementia, but dementia prevention strategies have yet to be comprehensively evaluated in people with diabetes. The Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability (FINGER) demonstrated cognitive benefits of a 2-year multidomain lifestyle intervention. However, given the intensive nature of FINGER, there is uncertainty about whether it can be implemented in other high-risk populations. Our aim was to explore attitudes towards dementia risk, and barriers to an intervention based on the FINGER model in older adults with type 2 diabetes living in rural areas of Ireland. METHODS: Focus groups were conducted with 21 adults (11 men and 10 women) aged 60+ years with type 2 diabetes living in border regions of north and south Ireland. Data were analysed using thematic analysis. RESULTS: There was limited understanding of diabetes as a risk factor for late-life dementia. The main barriers to engagement with the multidomain intervention were eating foods that were not compatible with cultural norms, time and travel constraints, and perceived lack of self-efficacy and self-motivation for adopting the desired diet, exercise and computerised cognitive training (CCT) behaviours. Facilitators for intervention acceptability included the provision of culturally tailored and personalised education, support from a trusted source, and inclusion of goal setting and self-monitoring behavioural strategies. CONCLUSIONS: While there was high acceptability for a brain health intervention, several barriers including cultural food norms and low self-efficacy for adopting the diet, exercise and CCT components would need to be considered in the intervention design. Findings from this study will be used to inform local decisions regarding the adaptation of FINGER for people with type 2 diabetes. The feasibility of the adapted multidomain intervention will then be evaluated in a future pilot trial.

Food insecurity and brain health in adults: A systematic review.

Food insecurity has been associated with adverse effects on physical health and well-being in both high and low-income countries, but effects on brain health are not clear. The purpose of this systematic review was to determine the relationship between food insecurity and important brain health outcomes in adults including depression, stroke, cognitive impairment and dementia. Electronic databases were searched to find studies which investigated relations between food insecurity and predefined brain health outcomes. Thirty studies met the inclusion criteria for review of which 23 were conducted in high income countries and seven in low- or middle-income countries. Most studies (n = 24) were cross-sectional, five were prospective and 1 was a case-control design. Seven studies reporting outcomes relating to cognitive performance and 24 relating to depression. No studies investigated relations between food insecurity and stroke or dementia. There was substantial heterogeneity in the populations studied as well as measures of food insecurity and outcomes which made comparisons between studies difficult. Overall, the findings highlighted that individuals who were food insecure had increased likelihood of depressive symptoms and poorer global cognition than those who were food secure. It is possible that social support and food aid programmes attenuate the effects of food insecurity on depressive symptoms. Future research is needed to determine whether interventions to alleviate food insecurity can benefit brain health in vulnerable populations.

The feasibility of a peer support intervention to encourage adoption and maintenance of a Mediterranean diet in established community groups at increased CVD risk: the TEAM-MED EXTEND study: a pilot cluster randomised controlled trial.

This study aimed to evaluate the feasibility of a peer support intervention to encourage adoption and maintenance of a Mediterranean diet (MD) in established community groups where existing social support may assist the behaviour change process. Four established community groups with members at increased Cardiovascular Disease (CVD) risk and homogenous in gender were recruited and randomised to receive either a 12-month Peer Support (PS) intervention (PSG) (n 2) or a Minimal Support intervention (educational materials only) (MSG) (n 2). The feasibility of the intervention was assessed using recruitment and retention rates, assessing the variability of outcome measures (primary outcome: adoption of an MD at 6 months (using a Mediterranean Diet Score (MDS)) and process evaluation measures including qualitative interviews. Recruitment rates for community groups (n 4/8), participants (n 31/51) and peer supporters (n 6/14) were 50 %, 61 % and 43 %, respectively. The recruitment strategy faced several challenges with recruitment and retention of participants, leading to a smaller sample than intended. At 12 months, a 65 % and 76·5 % retention rate for PSG and MSG participants was observed, respectively. A > 2-point increase in MDS was observed in both the PSG and the MSG at 6 months, maintained at 12 months. An increase in MD adherence was evident in both groups during follow-up; however, the challenges faced in recruitment and retention suggest a definitive study of the peer support intervention using current methods is not feasible and refinement based on the current feasibility study should be incorporated. Lessons learned during the implementation of this intervention will help inform future interventions in this area.

Trial to Encourage Adoption and Maintenance of a MEditerranean Diet (TEAM-MED): a randomised pilot trial of a peer support intervention for dietary behaviour change in adults from a Northern European population at high CVD risk.

Adhering to a Mediterranean diet (MD) is associated with reduced CVD risk. This study aimed to explore methods of increasing MD adoption in a non-Mediterranean population at high risk of CVD, including assessing the feasibility of a developed peer support intervention. The Trial to Encourage Adoption and Maintenance of a MEditerranean Diet was a 12-month pilot parallel group RCT involving individuals aged ≥ 40 year, with low MD adherence, who were overweight, and had an estimated CVD risk ≥ 20 % over ten years. It explored three interventions, a peer support group, a dietician-led support group and a minimal support group to encourage dietary behaviour change and monitored variability in Mediterranean Diet Score (MDS) over time and between the intervention groups, alongside measurement of markers of nutritional status and cardiovascular risk. 118 individuals were assessed for eligibility, and 75 (64 %) were eligible. After 12 months, there was a retention rate of 69 % (peer support group 59 %; DSG 88 %; MSG 63 %). For all participants, increases in MDS were observed over 12 months (P < 0·001), both in original MDS data and when imputed data were used. Improvements in BMI, HbA1c levels, systolic and diastolic blood pressure in the population as a whole. This pilot study has demonstrated that a non-Mediterranean adult population at high CVD risk can make dietary behaviour change over a 12-month period towards an MD. The study also highlights the feasibility of a peer support intervention to encourage MD behaviour change amongst this population group and will inform a definitive trial.

The effectiveness of peer-supported interventions for encouraging dietary behaviour change in adults: a systematic review.

OBJECTIVE: There is an urgent need to find effective methods of supporting individuals to make dietary behaviour changes. Peer-supported interventions (PSI) have been suggested as a cost-effective strategy to support chronic disease self-management. However, the effect of PSI on dietary behaviour is unclear. The present systematic review aimed to assess the effectiveness of PSI for encouraging dietary behaviour change in adults and to consider intervention characteristics linked with effectiveness. DESIGN: Electronic databases were searched until June 2018 for randomised controlled trials assessing the effectiveness of PSI compared with an alternative intervention and/or control on a dietary related outcome in adults. Following title and abstract screening, two reviewers independently screened full texts and data were extracted by one reviewer and independently checked by another. Results were synthesised narratively. SETTING: Randomised controlled trials.ParticipantsAdult studies. RESULTS: The fifty-four included studies varied in participants, intervention details and results. More PSI reported a positive or mixed effect on diet than no effect. Most interventions used a group model and were lay-led by peer supporters. Several studies did not report intervention intensity, fidelity and peer training and support in detail. Studies reporting positive effects employed more behaviour change techniques (BCT) than studies reporting no effect; however, heterogeneity between studies was considerable. CONCLUSIONS: As evidence was mixed, further interventions need to assess the effect of PSI on dietary behaviour, describe intervention content (theoretical basis, BCT, intensity and peer training/support) and include a detailed process evaluation.

Diet Quality Indices and Leukocyte Telomere Length Among Healthy US Adults: Data From the National Health and Nutrition Examination Survey, 1999-2002.

Aging is the biggest risk factor for the development of chronic diseases. Telomere length may represent one important mechanism by which dietary intake influences risk of age-related diseases; however, it is unknown which diet pattern is most strongly related to telomere length. We compared the relationships between 4 evidence-based diet quality indices and leukocyte telomere length in a nationally representative sample of healthy adults, and the extent to which these associations differed between men and women. Data on 4,758 adults aged 20-65 years with no prior diagnosis of major chronic disease were obtained from the 1999-2002 cycles of the National Health and Nutrition Examination Survey. Diet was assessed using one 24-hour dietary recall. After adjustment for sociodemographic and health characteristics, comparison of the top and bottom quintiles showed that higher Healthy Eating Index 2010 scores (ß = 0.065, 95% confidence interval (CI): 0.018, 0.112; P-trend = 0.007), Alternate Healthy Eating Index 2010 scores (ß = 0.054, 95% CI: 0.010, 0.097; P-trend = 0.007), Mediterranean Diet scores (ß = 0.058, 95% CI: 0.017, 0.098; P-trend = 0.008), and Dietary Approaches to Stop Hypertension (DASH) scores (ß = 0.052, 95% CI: 0.014, 0.090; P-trend = 0.007) were each associated with longer telomere length in women. These results may provide insight into the complex associations between optimal nutrition and longevity. Further investigation is needed to understand why associations were not observed in men.

Effect of dietary interventions in mild cognitive impairment: a systematic review.

Diet has been investigated in relation to its ability to promote cognitive function. However, evidence is currently limited and has rarely been systematically reviewed, particularly in a mild cognitive impairment (MCI) population. This review examined the effect of diet on cognitive outcomes in MCI patients. A total of five databases were searched to find randomised controlled trial (RCT) studies, with diet as the main focus, in MCI participants. The primary outcome was incident dementia and/or Alzheimer's disease (AD) and secondary outcomes included cognitive function across different domains using validated neuropsychological tests. Sixteen studies met the inclusion criteria. There was a high degree of heterogeneity relating to the nature of the dietary intervention and cognitive outcomes measured, thus making study comparisons difficult. Supplementation with vitamin E (one study, n 516), ginkgo biloba (one study, n 482) or Fortasyn Connect (one study, n 311) had no significant effect on progression from MCI to dementia and/or AD. For cognitive function, the findings showed some improvements in performance, particularly in memory, with the most consistent results shown by B vitamins, including folic acid (one study, n 266), folic acid alone (one study, n 180), DHA and EPA (two studies, n 36 and n 86), DHA (one study, n 240) and flavonol supplementation (one study, n 90). The findings indicate that dietary factors may have a potential benefit for cognitive function in MCI patients. Further well-designed trials are needed, with standardised and robust measures of cognition to investigate the influence of diet on cognitive status.

Development of a peer support intervention to encourage dietary behaviour change towards a Mediterranean diet in adults at high cardiovascular risk.

BACKGROUND: Mediterranean diet (MD) interventions are demonstrated to significantly reduce cardiovascular disease (CVD) risk but are typically resource intensive and delivered by health professionals. There is considerable interest to develop interventions that target sustained dietary behaviour change and that are feasible to scale-up for wider public health benefit. The aim of this paper is to describe the process used to develop a peer support intervention to encourage dietary behaviour change towards a MD in non-Mediterranean adults at high CVD risk. METHODS: The Medical Research Council (MRC) and Behaviour Change Wheel (BCW) frameworks and the COM-B (Capability, Opportunity, Motivation, Behaviour) theoretical model were used to guide the intervention development process. We used a combination of evidence synthesis and qualitative research with the target population, health professionals, and community health personnel to develop the intervention over three main stages: (1) we identified the evidence base and selected dietary behaviours that needed to change, (2) we developed a theoretical basis for how the intervention might encourage behaviour change towards a MD and selected intervention functions that could drive the desired MD behaviour change, and (3) we defined the intervention content and modelled outcomes. RESULTS: A theory-based, culturally tailored, peer support intervention was developed to specifically target behaviour change towards a MD in the target population. The intervention was a group-based program delivered by trained peer volunteers over 12-months, and incorporated strategies to enhance social support, self-efficacy, problem-solving, knowledge, and attitudes to address identified barriers to adopting a MD from the COM-B analysis. CONCLUSIONS: The MRC and BCW frameworks provided a systematic and complementary process for development of a theory-based peer support intervention to encourage dietary behaviour change towards a MD in non-Mediterranean adults at high CVD risk. The next step is to evaluate feasibility, acceptability, and diet behaviour change outcomes in response to the peer support intervention (change towards a MD and nutrient biomarkers) using a randomized controlled trial design.

A qualitative analysis exploring preferred methods of peer support to encourage adherence to a Mediterranean diet in a Northern European population at high risk of cardiovascular disease.

BACKGROUND: Epidemiological and randomised controlled trial evidence demonstrates that adherence to a Mediterranean diet (MD) can reduce cardiovascular disease (CVD) risk. However, methods used to support dietary change have been intensive and expensive. Peer support has been suggested as a possible cost-effective method to encourage adherence to a MD in at risk populations, although development of such a programme has not been explored. The purpose of this study was to use mixed-methods to determine the preferred peer support approach to encourage adherence to a MD. METHODS: Qualitative (focus groups) and quantitative methods (questionnaire and preference scoring sheet) were used to determine preferred methods of peer support. Sixty-seven high CVD risk participants took part in 12 focus groups (60% female, mean age 64 years) and completed a questionnaire and preference scoring sheet. Focus group data were transcribed and thematically analysed. RESULTS: The mean preference score (1 being most preferred and 5 being least preferred) for group support was 1.5, compared to 3.4 for peer mentorship, 4.0 for telephone peer support and 4.0 for internet peer support. Three key themes were identified from the transcripts: 1. Components of an effective peer support group: discussions around group peer support were predominantly positive. It was suggested that an effective group develops from people who consider themselves similar to each other meeting face-to-face, leading to the development of a group identity that embraces trust and honesty. 2. Catalysing Motivation: participants discussed that a group peer support model could facilitate interpersonal motivations including encouragement, competitiveness and accountability. 3. Stepping Stones of Change: participants conceptualised change as a process, and discussed that, throughout the process, different models of peer support might be more or less useful. CONCLUSION: A group-based approach was the preferred method of peer support to encourage a population at high risk of CVD to adhere to a MD. This finding should be recognised in the development of interventions to encourage adoption of a MD in a Northern European population.

Increasing Fruit and Vegetable Intake Has No Dose-Response Effect on Conventional Cardiovascular Risk Factors in Overweight Adults at High Risk of Developing Cardiovascular Disease.

BACKGROUND: Improving diet and lifestyle is important for prevention of cardiovascular disease (CVD). Observational evidence suggests that increasing fruit and vegetable (FV) consumption may lower CVD risk, largely through modulation of established risk factors, but intervention data are required to fully elucidate the mechanisms by which FVs exert benefits on vascular health. OBJECTIVE: The aim of this study was to examine the dose-response effect of FV intake on cardiovascular risk factors in adults at high CVD risk. METHODS: This was a randomized controlled parallel group study involving overweight adults (BMI: >27 and ≤35 kg/m(2)) with a habitually low FV intake (≤160 g/d) and a high total risk of developing CVD (estimated ≥20% over 10 y). After a 4-wk run-in period where FV intake was limited to <2 portions/d (<160 g/d), 92 eligible participants were randomly assigned to 1 of 3 groups: to consume either 2, 4, or 7 portions (equivalent to 160 g, 320 g, or 560 g, respectively) of FVs daily for 12 consecutive weeks. Fasting venous blood samples were collected at baseline (week 4) and post-intervention (week 16) for analysis of lipid fractions and high-sensitivity C-reactive protein (hsCRP) concentrations. Compliance with the FV intervention was determined with use of self-reported FV intake and biomarkers of micronutrient status. Ambulatory blood pressure and body composition were also measured pre- and post-intervention. RESULTS: A total of 89 participants completed the study and body composition remained stable throughout the intervention period. Despite good compliance with the intervention, no significant difference was found between the FV groups for change in measures of ambulatory blood pressure, plasma lipids, or hsCRP concentrations. CONCLUSIONS: There was no evidence of a dose-response effect of FV intake on conventional CVD risk factors measured in overweight adults at high CVD risk. This trial was registered at clinicaltrials.gov as NCT00874341.

Diet patterns and cognitive performance in a UK Female Twin Registry (TwinsUK).

BACKGROUND: Plant-based diets may provide protection against cognitive decline and Alzheimer's disease, but observational data have not been consistent. Previous studies include early life confounding from socioeconomic conditions and genetics that are known to influence both cognitive performance and diet behaviour. This study investigated associations between Mediterranean (MED) diet and MIND diets and cognitive performance accounting for shared genotype and early-life environmental exposures in female twins. METHODS: Diet scores were examined in 509 female twins enrolled in TwinsUK study. The Cambridge Neuropsychological Test Automated Battery was used to assess cognition at baseline and 10 years later (in n = 275). A co-twin case-control study for discordant monozygotic (MZ) twins examined effects of diet on cognitive performance independent of genetic factors. Differences in relative abundance of taxa at 10-year follow-up were explored in subsamples. RESULTS: Each 1-point increase in MIND or MED diet score was associated with 1.75 (95% CI: - 2.96, - 0.54, p = 0.005 and q = 0.11) and 1.67 (95% CI: - 2.71, - 0.65, p = 0.002 and q = 0.02) fewer respective errors in paired-associates learning. Within each MZ pair, the twin with the high diet score had better preservation in spatial span especially for MED diet (p = 0.02). There were no differences between diet scores and 10-year change in the other cognitive tests. MIND diet adherence was associated with higher relative abundance of Ruminococcaceae UCG-010 (0.30% (95% CI 0.17, 0.62), q = 0.05) which was also associated with less decline in global cognition over 10 years (0.22 (95% CI 0.06, 0.39), p = 0.01). CONCLUSIONS: MIND or MED diets could help to preserve some cognitive abilities in midlife, particularly episodic and visuospatial working memory. Effects may be mediated by high dietary fibre content and increased abundance of short-chain fatty acid producing gut bacteria. Longer follow-up with repeated measures of cognition will determine whether diet can influence changes in cognition occurring in older age.

The feasibility and acceptability of a rewards system based on food purchasing behaviour in secondary school cashless canteens: the Eat4Treats (E4T) cluster feasibility, non-randomised, controlled intervention study.

BACKGROUND: Using rewards may be an effective method to positively influence children's eating behaviour but evidence to date is limited, particularly in older children. The cashless canteen systems in schools provides a unique opportunity to implement a food-based reward scheme but intervention development work and feasibility testing is needed. The overall aim of the E4T feasibility study was to examine the feasibility and acceptability of implementing a rewards scheme based on the food purchasing behaviour of pupils in cashless canteens in secondary schools. METHODS: A non-randomised, controlled, parallel-group cluster feasibility study conducted in four secondary schools (two intervention and two control) serving areas of the highest social deprivation in Northern Ireland. During the 4-month trial, pupils earned points for foods purchased at the school canteen, with better nutritional choices having a higher value. Pupils could exchange the points they earned for rewards (e.g. stationery, vouchers, sports equipment) via the E4T website. Qualitative and quantitative data was collected from year 9 and 10 pupils (boys and girls aged 12-14 years), teachers and canteen staff to address the feasibility questions. RESULTS: Two intervention (one urban, one rural) and one control (urban) school completed the study. Seventy-one percent of 12-14-year-old pupils consented to take part; 1% of parents opted their child out of the study. Questionnaire completion rates were high (6 and 11% of questionnaires were partially completed at baseline and follow-up respectively). Collecting data on food consumed in the canteen was challenging logistically. Focus groups with pupils indicated that the overall concept of E4T was well received and there was a high degree of satisfaction with the rewards available. Pupils and teachers made several suggestions for improvements. CONCLUSIONS: E4T was successfully implemented as a result of collaboration between schools, school canteens and cashless canteen providers working with a multidisciplinary research team. It was acceptable to pupils, teachers and canteen staff. The findings suggest a few areas for refining implementation and evaluation processes that would need to be considered in the design of a larger trial, particularly resources required to streamline implementation and ways to optimise pupil engagement. TRIAL REGISTRATION: Under review with https://www. CLINICALTRIALS: gov (retrospective registration-reg number and weblink to be added).

Adherence to the Eatwell Guide and population and planetary health: A Rank Prize Forum report.

This report summarises a Forum conducted in June 2023 to explore the current state of the knowledge around the Eatwell Guide, which is the UK government's healthy eating tool, in relation to population and planetary health. The 1.5-day Forum highlighted the limited, albeit promising evidence linking higher adherence to the Eatwell Guide with favourable health outcomes, including reduced overall mortality risk, lower abdominal obesity in post-menopausal women and improved cardiometabolic health markers. Similarly, evidence was presented to suggest that higher adherence to the Eatwell Guide is associated with reduced greenhouse gas emissions. Presentations were given around cultural adaptations of the Eatwell Guide, including African Heritage and South Asian versions, which are designed to increase the acceptability and uptake of the Eatwell Guide in these communities in the United Kingdom. Presentations highlighted ongoing work relevant to the applications of the Eatwell Guide in randomised controlled trials and public health settings, including the development of a screening tool to quantify Eatwell Guide adherence. The Forum ended with a World Café-style event, in which the strengths and limitations of the Eatwell Guide were discussed, and directions for future research were identified. This Forum report serves as a primer on the current state of the knowledge on the Eatwell Guide and population and planetary health and will be of interest to researchers, healthcare professionals and public health officials.

Whole Dietary Patterns, Cognitive Decline and Cognitive Disorders: A Systematic Review of Prospective and Intervention Studies.

Dementia prevalence is a global public health concern. Adherence towards a healthy dietary pattern (DP) may reduce the risk of cognitive decline and dementia. This narrative systematic review aimed to synthesise prospective and intervention study data to evaluate the impact of a-posteriori and a-priori derived DPs on cognitive ageing, from cognitive decline to incident dementia. Ninety-three studies were included: 83 prospective studies and 10 randomised controlled trials (RCT). Most prospective studies (77%) examined a-priori DPs, with the Mediterranean diet examined most frequently. A total of 52% of prospective and 50% of RCTs reported a protective relationship between 'healthy' DPs and global cognitive decline. Overall, 59% of prospective studies reported positive associations between healthy DPs and risk of cognitive disorder. Incident cognitive disorder was examined by only one intervention study (subgroup analysis) which reported a beneficial effect of a low-fat diet on risk of probable dementia in women. Unhealthy DPs were examined less frequently (n = 17; 21%), with 41% of these studies reporting associations between adherence and poorer cognitive outcomes. Overall, there were mixed results for healthy and unhealthy DPs on cognition, likely due to between-study heterogeneity. Standardisation of diet exposure and cognitive outcome measurement would help to reduce this. Future research would benefit from investigating effects of culturally appropriate DPs on individual cognitive domains and incident cognitive disorders in diverse and high-risk populations.

A peer support dietary change intervention for encouraging adoption and maintenance of the Mediterranean diet in a non-Mediterranean population (TEAM-MED): lessons learned and suggested improvements.

Peer support interventions for dietary change may offer cost-effective alternatives to interventions led by health professionals. This process evaluation of a trial to encourage the adoption and maintenance of a Mediterranean diet in a Northern European population at high CVD risk (TEAM-MED) aimed to investigate the feasibility of implementing a group-based peer support intervention for dietary change, positive elements of the intervention and aspects that could be improved. Data on training and support for the peer supporters; intervention fidelity and acceptability; acceptability of data collection processes for the trial and reasons for withdrawal from the trial were considered. Data were collected from observations, questionnaires and interviews, with both peer supporters and trial participants. Peer supporters were recruited and trained to result in successful implementation of the intervention; all intended sessions were run, with the majority of elements included. Peer supporters were complimentary of the training, and positive comments from participants centred around the peer supporters, the intervention materials and the supportive nature of the group sessions. Attendance at the group sessions, however, waned over the intervention, with suggested effects on intervention engagement, enthusiasm and group cohesion. Reduced attendance was reportedly a result of meeting (in)frequency and organisational concerns, but increased social activities and group-based activities may also increase engagement, group cohesion and attendance. The peer support intervention was successfully implemented and tested, but improvements can be suggested and may enhance the successful nature of these types of interventions. Some consideration of personal preferences may also improve outcomes.

Effects of PROtein enriched MEDiterranean Diet and EXercise on nutritional status and cognition in adults at risk of undernutrition and cognitive decline: the PROMED-EX Randomised Controlled Trial.

INTRODUCTION: Undernutrition leading to unplanned weight loss is common in older age and has been linked to increased dementia risk in later life. Weight loss can precede dementia by a decade or more, providing a unique opportunity for early intervention to correct undernutrition and potentially prevent or delay cognitive impairment. The combined effects of diet and exercise on undernutrition have not yet been evaluated. The objective of this trial is to determine the effect of a protein-enriched Mediterranean diet, with and without exercise, on nutritional status and cognitive performance in older adults at risk of undernutrition and cognitive decline. METHODS: One hundred and five participants aged 60 years and over at risk of undernutrition and with subjective cognitive decline will be recruited to participate in a 6-month, single-blind, parallel-group randomised controlled trial. Participants will be block randomised into one of three groups: group 1-PROMED-EX (diet+exercise), group 2-PROMED (diet only) and group 3-standard care (control). The primary outcome is nutritional status measured using the Mini Nutritional Assessment. Secondary outcomes include cognitive function, nutritional intake, body composition, physical function and quality of life. Mechanistic pathways for potential diet and exercise-induced change in nutritional status and cognition will be explored by measuring inflammatory, metabolic, nutritional and metabolomic biomarkers. ETHICS AND DISSEMINATION: The study is approved by the UK Office for Research Ethics Committee (ref: 21/NW/0215). Written informed consent will be obtained from participants prior to recruitment. Research results will be disseminated to the public via meetings and media and the scientific community through conference presentations and publication in academic journals. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT05166564).

Vegetarian diets, low-meat diets and health: a review.

OBJECTIVE: To review the epidemiological evidence for vegetarian diets, low-meat dietary patterns and their association with health status in adults. DESIGN: Published literature review focusing primarily on prospective studies and meta-analyses examining the association between vegetarian diets and health outcomes. RESULTS: Both vegetarian diets and prudent diets allowing small amounts of red meat are associated with reduced risk of diseases, particularly CHD and type 2 diabetes. There is limited evidence of an association between vegetarian diets and cancer prevention. Evidence linking red meat intake, particularly processed meat, and increased risk of CHD, cancer and type 2 diabetes is convincing and provides indirect support for consumption of a plant-based diet. CONCLUSIONS: The health benefits of vegetarian diets are not unique. Prudent plant-based dietary patterns which also allow small intakes of red meat, fish and dairy products have demonstrated significant improvements in health status as well. At this time an optimal dietary intake for health status is unknown. Plant-based diets contain a host of food and nutrients known to have independent health benefits. While vegetarian diets have not shown any adverse effects on health, restrictive and monotonous vegetarian diets may result in nutrient deficiencies with deleterious effects on health. For this reason, appropriate advice is important to ensure a vegetarian diet is nutritionally adequate especially for vulnerable groups.