A Mediterranean diet supplemented with dairy foods improves mood and processing speed in an Australian sample: results from the MedDairy randomized controlled trial

Association between 29 food groups of diet quality questionnaire and perceived stress in Chinese adults: a prospective study from China health and nutrition survey

PURPOSE

Diet plays a fundamental role in promoting resilience against stress-related disorders. We aimed to examine the overall and sex-specific association between food groups and perceived stress in adults.

METHODS

We analyzed the prospective data of 7,434 adults who completed both the 2011 and 2015 surveys of the China Health and Nutrition Survey (CHNS). The Diet Quality Questionnaire (DQQ) was used to code all the food items of 2011 dietary intake into 29 food groups, and perceived stress in 2015 was measured using a 14-item perceived stress scale (PSS-14). Univariate analysis and logistic regression models were used to examine the relationship between food groups and perceived stress.

RESULTS

People who perceived a higher level of stress (PSS-14 total score > 25) made up 41.5% and 45.1% of the male and female groups, respectively (χ2 = 9.605, p = 0.002). Individuals with increased intake of food groups such as legumes, other vegetables, other fruits, yogurt, poultry, fish & seafood, fluid milk, and fruit juice were less likely to experience a higher level of psychological stress (OR range: 0.544-0.892, p < 0.05). Additionally, we found sex-specific associations between food groups and perceived stress. The difference in the proportion of food groups, such as fluid milk and fish & seafood, between the two stress groups in men was statistically significant (p < 0.025). In the female group, the distribution of eight food groups, like legumes and nuts & seeds, between the two stress groups was statistically significant (p < 0.025).

CONCLUSION

This study indicated that food groups were differentially associated with perceived stress.

Mood disturbance, but not overall diet quality, is associated with fecal microbiome diversity in free-living adults

OBJECTIVES

To investigate the gut-brain axis, we explored the relationships among mood disturbance (MD), diet quality (DQ), and fecal microbiota in free-living adults.

METHODS

A cross-sectional analysis was conducted with data from 75 healthy adults enrolled in two studies. Anthropometrics, 16s rRNA gene sequencing of fecal microbes, DQ as assessed by Healthy Eating Index-2015 (HEI), and MD determined by Profile of Mood States (POMS) were included. Alpha-diversity and DQ differences were explored between low (n = 37) and high MD (n = 38) groups. Spearman correlations were used to investigate relationships between alpha-diversity, DQ, and POMS subscales. Moderation analysis explored the effect of HEI score on the relationship between MD and alpha-diversity.

RESULTS

Participants were mostly white (67%), 54.5 years old (±11.8), and overweight (28.5 ± 6.5 kg/m2). Shannon and Simpson indices indicate higher alpha-diversity in participants with low MD compared to high MD (p = 0.004 and p = 0.008, respectively). Simpson and Shannon indices were correlated with subscale of anger (rho = -0.303, p = 0.011; rho = -0.265, p = 0.027, respectively)and total MD (rho = -0.404, p = 0.001; rho = -0.357, p = 0.002, respectively). Refined grains were associated with fatigue and tension subscales (rho = 0.428, p < 0.001; rho = 0.302, p = 0.014, respectively). DQ did not significantly moderate the relationship between alpha-diversity and mood disturbance (F(7, 53) = 2.00, p = 0.072, R2 = 0.209). Shannon index was a significant predictor of MD (b = -4.39, t(53) = -2.55, p = 0.014), but total HEI score and the interaction (Shannon index*HEI score) were not significant.

DISCUSSION

Greater bacterial diversity was associated with lower MD, and DQ was associated with various mood state subscales in this sample of adults.

Dietary eating patterns, dairy consumption, and anxiety: A systematic literature review

BACKGROUND

Nutrition affects both physical and mental health but evidence is mixed regarding potential associations between anxiety and diet, particularly dairy consumption. We conducted a systematic literature review (SLR) of dairy consumption and/or various dietary patterns and risk of anxiety.

METHODS

Literature searches were conducted in PubMed and Embase. All study designs except case reports, small case series, and SLRs were considered for inclusion. Reference lists of previously published SLRs were reviewed for any relevant additional studies. Studies of populations without dairy sensitivities exploring the association between dietary patterns and/or dairy consumption and anxiety published through May 2022 were identified using predefined eligibility criteria. Study quality was determined using the Academy of Nutrition and Dietetics Quality Criteria Checklist.

RESULTS

For this SLR, 132 studies were included; 80 were cross-sectional. Studies examined different dietary patterns (e.g., Mediterranean, gluten-free) and anxiety using various anxiety scales, with 19 studies specifically reporting on whole dairy consumption and anxiety. Dairy consumption was significantly associated with a lower risk of anxiety in 7 studies, while the remaining 12 studies showed no significant associations. Evidence was mixed for the association between various dietary patterns and anxiety, but more studies observed a lower risk of anxiety with greater adherence to "healthy" diets (e.g., Mediterranean, diet quality score, vegetarian/vegan) than a higher risk. Notable heterogeneity in study populations, time periods, geographical locations, dietary assessment methods, and anxiety scales was observed.

CONCLUSIONS

The results of this SLR suggest a potential link between diet including diary consumption and anxiety, but future studies, especially with longitudinal designs that measure diet and anxiety at several timepoints and comprehensively adjust for confounders, are needed to fully understand the relationship between diet and anxiety.

Exploring the Therapeutic Potential of Gamma-Aminobutyric Acid in Stress and Depressive Disorders through the Gut-Brain Axis

Research conducted on individuals with depression reveals that major depressive disorders (MDDs) coincide with diminished levels of the inhibitory neurotransmitter γ-aminobutyric acid (GABA) in the brain, as well as modifications in the subunit composition of the primary receptors (GABAA receptors) responsible for mediating GABAergic inhibition. Furthermore, there is substantial evidence supporting the significant role of GABA in regulating stress within the brain, which is a pivotal vulnerability factor in mood disorders. GABA is readily available and approved as a food supplement in many countries. Although there is substantial evidence indicating that orally ingested GABA may affect GABA receptors in peripheral tissues, there is comparatively less evidence supporting its direct action within the brain. Emerging evidence highlights that oral GABA intake may exert beneficial effects on the brain and psyche through the gut-brain axis. While GABA enjoys wide consumer acceptance in Eastern Asian markets, with many consumers reporting favorable effects on stress regulation, mood, and sleep, rigorous independent research is still largely lacking. Basic research, coupled with initial clinical findings, makes GABA an intriguing neuro-nutritional compound deserving of clinical studies in individuals with depression and other psychological problems.

Interactions between Mediterranean Diet Supplemented with Dairy Foods and the Gut Microbiota Influence Cardiovascular Health in an Australian Population

The impact of a Mediterranean diet on the intestinal microbiome has been linked to its health benefits. We aim to evaluate the effects of a Mediterranean diet supplemented with dairy foods on the gut microbiome in Australians at risk of cardiovascular disease. In a randomised controlled cross-over study, 34 adults with a systolic blood pressure ≥120 mmHg and with risk factors for cardiovascular disease were randomly allocated to a Mediterranean diet with 3-4 daily serves of dairy foods (Australian recommended daily intake (RDI) of 1000-1300 mg per day (MedDairy)) or a low-fat (LFD) control diet. Between each 8-week diet, participants underwent an 8-week washout period. Microbiota characteristics of stool samples collected at the start and end of each diet period were determined by 16S rRNA amplicon sequencing. MedDairy-associated effects on bacterial relative abundance were correlated with clinical, anthropometric, and cognitive outcomes. No change in the overall faecal microbial structure or composition was observed with either diet (p > 0.05). The MedDairy diet was associated with changes in the relative abundance of several bacterial taxa, including an increase in Butyricicoccus and a decrease in Colinsella and Veillonella (p < 0.05). Increases in Butyricicoccus relative abundance over 8 weeks were inversely correlated with lower systolic blood pressure (r = -0.38, p = 0.026) and positively correlated with changes in fasting glucose levels (r = 0.39, p = 0.019), specifically for the MedDairy group. No significant associations were observed between the altered taxa and anthropometric or cognitive measures (p > 0.05). Compared to a low-fat control diet, the MedDairy diet resulted in changes in the abundance of specific gut bacteria, which were associated with clinical outcomes in adults at risk of CVD.

The Dietary Carbohydrate/Fat-Ratio and Cognitive Performance: Panel Analyses in Older Adults at Risk for Dementia

Background

Roughly 80% of total energy intake (TEI) in most human diets originates from digestible carbohydrates (eCarb) and fat (eFat), but the impact of their proportions on cognitive performance is poorly understood.

Objectives

Our primary aim was to investigate estimates of global cognition in relation to macronutrient intake, with the log-ratio eCarb/eFat (CFr) as the primary predictor variable of interest. Secondary predictors were protein and the saturated/total fat ratio. Exploratory comparisons of CFr with eCarb and eFat as separate predictors were an additional aim.

Methods

The observations were made on panel data (years 0, 1, 2) from the Finnish Geriatric Intervention Study to Prevent Cognitive Impairment and Disability, n = 1251; age 60-77 y; 47% females; selected by risk factors for dementia. Self-reported diet was assessed by 3-d food records. Global cognition was measured using a modified Neuropsychological Test Battery. A mixed linear regression model was used, adjusted for age, sex, education, body-mass index, cholesterol-lowering drugs, TEI, time, time × intervention/control group, with study site and subject as random factors. Estimates were standardized (mean = 0; SD = 1) with 95% CI.

Results

CFr had a negative estimate to global cognition (β = -0.022, CI: -0.039, -0.005; P = 0.011). The point estimate for protein was β = 0.013 (P = 0.41), and for the saturated/total fat ratio, associations with cognition were nonlinear. CFr correlated highly with eCarb (Pearson's r = 0.92) and eFat (r = -0.94). The point estimate for CFr fell between eCarb (β = -0.026, P < 0.001) and (inversely) eFat (β = 0.017, P = 0.090).

Conclusions

A lower CFr was associated with better global cognition among older adults at risk for dementia. Because this is an important target group for preventive interventions, clinical trials are warranted to further investigate the impact of macronutritional composition on cognitive health. The potential role of CFr as a predictor for cognitive health should be further studied.

The Brain-Gut-Microbiota Interplay in Depression: a key to design innovative therapeutic approaches

Depression is the most prevalent mental disorder in the world associated with huge socio-economic consequences. While depressive-related symptoms are well known, the molecular mechanisms underlying disease pathophysiology and progression remain largely unknown. The gut microbiota (GM) is emerging as a key regulator of the central nervous system homeostasis by exerting fundamental immune and metabolic functions. In turn, the brain influences the intestinal microbial composition through neuroendocrine signals, within the so-called gut microbiota-brain axis. The balance of this bidirectional crosstalk is important to ensure neurogenesis, preserve the integrity of the blood-brain barrier and avoid neuroinflammation. Conversely, dysbiosis and gut permeability negatively affect brain development, behavior, and cognition. Furthermore, although not fully defined yet, changes in the GM composition in depressed patients are reported to influence the pharmacokinetics of common antidepressants by affecting their absorption, metabolism, and activity. Similarly, neuropsychiatric drugs may shape in turn the GM with an impact on the efficacy and toxicity of the pharmacological intervention itself. Consequently, strategies aimed at re-establishing the correct homeostatic gut balance (i.e., prebiotics, probiotics, fecal microbiota transplantation, and dietary interventions) represent an innovative approach to improve the pharmacotherapy of depression. Among these, probiotics and the Mediterranean diet, alone or in combination with the standard of care, hold promise for clinical application. Therefore, the disclosure of the intricate network between GM and depression will give precious insights for innovative diagnostic and therapeutic approaches towards depression, with profound implications for drug development and clinical practice.

Study of Different Personalised Dietary Plans on Eating Behaviour, Body Image and Mood in Young Female Professional Handball Players: A Randomised Controlled Trial

Low energy availability may precede or be caused by cognitive disturbances in professional athletes. Related psychological problems include disordered eating patterns, body shape preoccupation, depression or anxiety. The objective of this research was to evaluate the effects of different personalised dietary plans on psychological factors in young professional female handball players with low energy availability. This 12-week randomised clinical trial involved 21 female players aged 22 ± 4 years, 172.0 ± 5.4 cm and 68.4 ± 6.7 kg divided into three groups (FD: free diet; MD: Mediterranean diet; HAD: high antioxidant diet). Eating behaviour (Eating Attitude Test, EAT-26: diet, bulimia and oral control subscales), body image (Body Shape Questionnaire, BSQ) and mood state (Profile of Mode State, POMS: tension, vigour, anger, depression, fatigue) were assessed. All participants showed low energy availability (<30 kcal/lean mass per day). The different plans showed no significant differences between them but significant differences over time within groups for the variables: body image, Tension, Vigour and Depression (p < 0.05). Eating behaviour improved slightly but did not show statistically significant changes. Following an adequate nutritional planning for athletes seems to improve the mood and body perception of young female handball players. A longer intervention period is required to assess the differences between diets and improvement of other parameters.

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.

Are Dietary Patterns Related to Cognitive Performance in 7-Year-Old Children? Evidence from a Birth Cohort in Friuli Venezia Giulia, Italy

Research from different sources supports a link between nutrition and neurodevelopment, but evidence is still sparse regarding the relationship between a posteriori dietary patterns (DPs) and cognitive performance in school-aged children. Within the Northern Adriatic Cohort II, Friuli Venezia Giulia, Italy, 379 7-year-old children were cross-sectionally evaluated. Dietary patterns were identified through a principal component factor analysis based on 37 nutrients from children’s 3-day dietary records. The Wechsler Intelligence Scale of Children (WISC-IV) test provided measures of cognitive performance, including the full-scale intelligence quotient (FSIQ) and single index scores. Each DP was related to FSIQ or single index scores through multiple robust linear regression models. We identified five DPs named “Dairy Products”, “Plant-based Foods”, “Fats”, “Meat and Potatoes”, and “Seafood” (63% of variance explained). After adjustment, no significant relationship was observed with the FSIQ score; positive associations were found between the “Seafood” DP and Verbal Comprehension Index or Perceptual Reasoning Index. The “Meat and Potatoes” and “Dairy Products” DPs were inversely associated with the Verbal Comprehension Index and Processing Speed Index scores, respectively. In the absence of a relation with the overall FSIQ score, single DPs might influence specific cognitive functions, including verbal and reasoning abilities, as targeted by single indexes, in the expected direction.

Effect of Mediterranean diet and Mediterranean diet plus calorie restriction on cognition, lifestyle, and cardiometabolic health: A randomized clinical trial

A Mediterranean diet and intentional weight loss each positively affect cognitive functioning. Combining both could produce synergistic effects on cognition. The purpose of this study is to compare a Mediterranean diet lifestyle intervention with and without caloric restriction versus control on cognition, lifestyle, and cardiometabolic disease. In a three-arm trial conducted between 2017 and 2020 in Chicago, one hundred and eight-five, 55–85-year-old, predominately non-Hispanic black females with obesity were randomized (2:2:1) to an 8-month Mediterranean diet plus caloric restriction intervention, Mediterranean diet alone, or control. The primary outcome was change from baseline to post-intervention in cognitive composite scores: attention, information & processing; executive function; and learning, memory, & recognition. Secondary outcomes were weight, lifestyle and cardiometabolic markers. The 8-month Mediterranean diet interventions did not significantly affect cognition. Adherence to a Mediterranean diet improved more in the Mediterranean diet plus caloric restriction arm (mean [SE] score change, +6.3 [0.7] points) and Mediterranean diet alone arm (+4.8 [0.7] points) relative to controls (+0.6 [0.9] points). Mean weight loss was greater among the Mediterranean diet plus caloric restriction arm (−4.6 [0.6] kg) compared to the Mediterranean diet alone (−2.6 [0.6] kg) and control arms (−0.6 [0.7] kg). The interventions did not affect activity or cardiometabolic risk markers; although, fasting insulin did decline in the Mediterranean diet plus caloric restriction arm relative to the Mediterranean diet alone and control arms. A Mediterranean diet lifestyle intervention with and without caloric restriction did not significantly affect cognitive function compared to controls. The Mediterranean diet interventions, however, significantly affected diet quality and body weight.

Mediterranean Diet, Interoception and Mental Health: Is it time to look beyond the 'Gut-Brain Axis'?

OBJECTIVE

A Mediterranean style diet (i.e., high in fruit, vegetables, fish, pulses, and wholegrains) is said to benefit psychological health. Many low-level interoceptive processes, such as those involved in the 'gut-brain' axis, are suggested to play a mechanistic role in in this relationship. However, interoceptive sensations in other domains, and at higher hierarchical levels of abstraction, have hitherto been overlooked. One domain often studied in relation to psychological health is cardioception. Therefore, we examined whether the Mediterranean diet was associated with first-order perceptual and second-order metacognitive cardioception.

METHODS

Participants completed the Heartbeat Detection Task, the Heartbeat Counting Task, and the EPIC-Norfolk Food Frequency Questionnaire from which diet was quantified.

RESULTS

Adherence to a Mediterranean style diet was associated with higher cardioceptive accuracy (i.e., perceptual performance) across both tasks. In addition, those consuming a Mediterranean diet had a better ability to detect errors in first order perceptual performance, and a lower prediction error (the magnitude of the difference between accuracy and confidence).

DISCUSSION

These findings indicated that deepening our understanding of how interoceptive processes beyond the 'gut-brain' axis are shaped by diet could deepen our understanding of the link between diet and mental health and wellbeing.

Healthy and Unhealthy Food Consumption in Relation to Quality of Life among Finnish Female Municipal Employees: A Cross-Sectional Study

Aspects of good quality of life (QoL) have been found to motivate people to make lifestyle changes. There is also evidence that certain dietary patterns are associated with QoL. The aim of this work was to examine whether consumption frequencies of healthy and unhealthy food items are associated with QoL in female employees. A cross-sectional study was conducted among 631 Finnish female employees (mean age 49 years, SD = 10) from 10 municipal work units in 2015. Information about the participants was collected by physical examination, laboratory tests, self-administered questionnaires, including the Food Frequency Questionnaire (FFQ), and from medical history. QoL was assessed with the EUROHIS-Quality of Life 8-item index. A significant positive association was seen between consumption frequency of healthy foods and the EUROHIS-QOL mean score (p = 0.002). The association was small but comprehensive, also involving most dimensions of QoL. The consumption frequency of unhealthy foods was not associated with QoL. These findings are relevant when designing diet counselling, since QoL is an outcome that has been found to motivate people to change their health habits. Recommending abundant use of healthy foods could be a simple and convenient way of diet counselling at many health care appointments, where time consuming approaches are difficult to conduct.

Inverse Association between Dietary Diversity Score Calculated from the Diet Quality Questionnaire and Psychological Stress in Chinese Adults: A Prospective Study from China Health and Nutrition Survey

Specific nutrients or dietary patterns influence an individual’s psychological stress. As a major aspect of a healthy diet, the influence of dietary diversity on psychological stress remains uncertain. Within these contexts, we aimed to examine the association between the dietary diversity score and psychological stress, using prospective data from the China Health and Nutrition Survey (CHNS). We included 7434 adult participants, with complete dietary information, in the 2011 wave, and followed-up with perceived stress scale (PSS-14) in the 2015 wave. The dietary intake of foods was coded into 29 food groups, using the DQQ for China, and the dietary diversity scores were obtained, using DQQ, by calculating the number of food groups consumed during one 24-h dietary recall. The univariate analysis, and logistic regression model were used to examine the relationship between psychological stress and diet diversity. Approximately half of the participants (4204, 56.55%) perceived a higher level of stress (PSS-14 total score > 25). Dietary diversity was lower in the higher-stress group (p for trend <0.0001). Unconditional multivariate logistic regression demonstrated that participants with higher daily dietary diversity were less likely to experience higher-level psychological stress, compared with participants with lower daily dietary diversity (ORs range: 0.480−0.809). Dietary diversity was found to be inversely associated with psychological stress, in this prospective analysis of a national population. Further studies are required to figure out the mechanism and effectiveness of dietary diversity on psychological stress.

Diet quality interventions to prevent neurocognitive decline: a systematic review and meta-analysis

OBJECTIVE

To determine the impact of diet quality interventions on neurocognitive decline in older adults.

DESIGN

Four databases were searched (Medline, EMBASE, CENTRAL and PsycINFO) for randomised controlled trials involving diet quality interventions and cognitive outcomes in older adults. Study quality was assessed using the Cochrane Risk of Bias tool. Outcomes selected for meta-analysis were memory and executive function, for which standardised mean differences (SMD) were calculated. Subgroup and sensitivity analyses were undertaken to explore causes of heterogeneity. Additional outcomes of global cognitive function, incident dementia, attention, language/verbal fluency, and processing speed were narratively synthesised.

RESULTS

Twelve studies were included, investigating the Mediterranean, Dietary Approaches to Stop Hypertension and Nordic diets. Risk of bias varied across studies. Dietary intervention had a significant effect on memory (SMD: 0.98; 95% CI: 0.39, 1.57; p = 0.001) and executive function (SMD: 2.02; 95% CI: 1.04, 3.01; p < 0.00001), although neither outcome was significant in sensitivity analyses. Heterogeneity was high (I² = 99%) prior to sensitivity analyses and low (I² = 0%) after. Results for narratively synthesised cognitive measures were inconsistent with no clear direction of effect.

CONCLUSION

The current body of evidence would suggest the effect of dietary intervention on neurocognitive decline in older adults is unclear given the considerable heterogeneity and bias present across studies. These findings should be interpreted with consideration to the limited number of studies that could be included and the large variation in study designs. Further randomised controlled trials with harmonised cognitive outcomes and assessments are needed to clarify direction of effect.

Oxidative stress, aging, antioxidant supplementation and their impact on human health: An overview

Aging is characterized by a progressive loss of tissue and organ function due to genetic and environmental factors, nutrition, and lifestyle. Oxidative stress is one the most important mechanisms of cellular senescence and increased frailty, resulting in several age-linked, noncommunicable diseases. Contributing events include genomic instability, telomere shortening, epigenetic mechanisms, reduced proteome homeostasis, altered stem-cell function, defective intercellular communication, progressive deregulation of nutrient sensing, mitochondrial dysfunction, and metabolic unbalance. These complex events and their interplay can be modulated by dietary habits and the ageing process, acting as potential measures of primary and secondary prevention. Promising nutritional approaches include the Mediterranean diet, the intake of dietary antioxidants, and the restriction of caloric intake. A comprehensive understanding of the ageing processes should promote new biomarkers of risk or diagnosis, but also beneficial treatments oriented to increase lifespan.

Effect of Dietary Intake Through Whole Foods on Cognitive Function: Review of Randomized Controlled Trials

PURPOSE OF REVIEW

This review evaluated recent randomized controlled trials (RCTs) examining the chronic intake of whole foods associated with the Mediterranean, Dietary Approaches to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurogenerative Delay (MIND), and ketogenic (KETO) diets on cognitive function.

RECENT FINDINGS

We identified RCTs related to olive oil (N = 3), nuts (N = 7), fatty fish (N = 1), lean meats (N = 4), fruits and vegetables (N = 9), legumes (N = 1), and low-fat dairy (N = 4), with 26/29 reporting positive results on at least one measure of cognition. We also identified 6 RCTs related to whole food-induced KETO diets, with half reporting positive effects on cognition. Variations in study design (i.e., generally the studies are < 6 months and include middle-aged and older, cognitively intact participants) and small sample sizes make it difficult to draw conclusions across studies; however, the current evidence from RCTs generally supports individual component intakes of these dietary patterns as an effective, nonpharmacological approach to improve cognitive health in adults.

Associations Between Dietary Patterns and Neuroimaging Markers: A Systematic Review

Dementia is a complex, growing challenge for population health worldwide. Dietary patterns (DPs) may offer an opportunity to beneficially influence cognitive ageing and potentially reduce an individuals’ risk of dementia through diet-related mechanisms. However, previous studies within this area have shown mixed results, which may be partly explained by the lack of sensitivity and accuracy within cognitive testing methods. Novel neuroimaging techniques provide a sensitive method to analyse brain changes preceding cognitive impairment which may have previously remained undetected. The purpose of this systematic review was to elucidate the role of DPs in relation to brain ageing processes, by summarising current prospective and intervention studies. Nine prospective studies met the inclusion criteria for the review, seven evaluated the Mediterranean diet (MeDi), one evaluated the Alternative Healthy Eating Index-2010, and one evaluated a posteriori derived DPs. No intervention studies were eligible for inclusion in this review. There was some evidence of an association between healthy DPs and neuroimaging markers including changes within these markers over time. Consequently, it is plausible that better adherence to such DPs may positively influence brain ageing and neurodegeneration. Future studies may benefit from the use of multi-modal neuroimaging techniques, to further investigate how adherence to a DP influences brain health. The review also highlights the crucial need for further intervention studies within this research area.

A Possible Antidepressive Effect of Dietary Interventions: Emergent Findings and Research Challenges

Purpose

Despite recent advancements in the treatment of depression, the prevalence of affected individuals continues to grow. The development of new strategies has been required and emerging evidence has linked a possible antidepressant effect with dietary interventions. In this review, we discuss recent findings about the possible antidepressant effect of dietary interventions with an emphasis on the results of randomized controlled trials.

Recent findings

A high consumption of refined sugars and saturated fat and a low dietary content of fruits and vegetables has been associated with the development of depression. There is evidence supporting a small to moderate beneficial effect of a Mediterranean-type diet in depression. In addition, new dietary protocols are being studied for their use as possible interventions, such as the ketogenic diet, Nordic diet, and plant-based diet.

Summary

Lifestyle interventions surrounding diet and nutrition are a relatively affordable way to enhance response to treatment and to be employed as an adjunct in mental health care. Most studies, however, are limited by the difficulty in controlling for the placebo effect. Mediterranean-style diets seem to be the most promising as an adjunctive treatment for mood disorders. Larger randomized controlled trials that could assess predictors of response to dietary interventions are needed to establish a clear positive effect of diet and guide clinical care and nutritional recommendations concerning mental health care.

The Relationship between Dietary Habits and Work Engagement among Female Finnish Municipal Employees

Background: Work engagement reflects work-related well-being. It is positively associated with health, life satisfaction, work efficiency, income level, and occupational prospects. However, little is known about the relationship between work engagement and diet. Methods: A cross-sectional study was conducted among female Finnish municipal employees (n = 630) in 2015. Work engagement was assessed using the Utrecht Work Engagement Index. The consumption of healthy and unhealthy food items was determined using a food frequency questionnaire. Sociodemographic factors, health behaviors, depressive and anxiety symptoms were assessed with self-administrated questionnaires. Results: Work engagement had a positive relationship with the daily consumption of healthy food items. This association remained significant even after adjusting for age, education years, financial situation, and physical activity. The frequency of consuming unhealthy food items showed no relationship with work engagement. Anxiety and depressive symptoms decreased linearly with the greater consumption of healthy foods. Conclusion: Frequent consumption of healthy food items is associated with higher work engagement, irrespectively of the consumption of unhealthy nutrients. These results encourage health care professionals to recommend healthy food items instead of forbidding unhealthy food, as well as employers to support healthy dietary habits among employees.

Relationships between Dairy and Calcium Intake and Mental Health Measures of Higher Education Students in the United States: Outcomes from Moderation Analyses

Background: The prevalence of mental health concerns among university students in the United States (U.S.) continues to increase, while current treatments, including medication and counseling, present shortcomings. Higher dairy and calcium intakes are associated with protective effects on mental health; however, previous studies have focused on investigating singular relationships between dairy and calcium intakes and mental health measures. A more complex exploration of these relationships is warranted to better examine whether increasing dairy and calcium intakes could serve as an intervention to improve mental health. The present study sought to further characterize the relationships between dairy and calcium intake, perceived stress, and a variety of mental health measures using linear regression and moderation analyses. Methods: The present cross-sectional study involved students studying at three large U.S. universities, and data collection occurred from April to May 2020 when students were learning remotely due to the COVID-19 pandemic. An online survey comprising validated tools was distributed among students to assess dairy and calcium intake, perceived stress, anxiety, negative and positive moods, rumination, and resilience, sleep quality and duration, dietary risk, and physical activity. Results: A total of 1233 students completed the study. Higher dairy and calcium intake was coincident with lower perceived stress and higher positive mood scores, while higher calcium intake was also coincident with lower anxiety, rumination, and higher resilience scores. Additionally, as calcium intake increased, the relationship between perceived stress and anxiety and the relationship between perceived stress and negative mood weakened. Dairy intake did not have this effect. Conclusions: Based on the results, and considering that calcium is a shortfall nutrient, universities should consider initiating programs and public health campaigns to promote dairy and calcium intake among this population.

Characterising activity and diet compositions for dementia prevention: protocol for the ACTIVate prospective longitudinal cohort study

INTRODUCTION

Approximately 40% of late-life dementia may be prevented by addressing modifiable risk factors, including physical activity and diet. Yet, it is currently unknown how multiple lifestyle factors interact to influence cognition. The ACTIVate Study aims to (1) explore associations between 24-hour time-use and diet compositions with changes in cognition and brain function; and (2) identify duration of time-use behaviours and the dietary compositions to optimise cognition and brain function.

METHODS AND ANALYSIS

This 3-year prospective longitudinal cohort study will recruit 448 adults aged 60-70 years across Adelaide and Newcastle, Australia. Time-use data will be collected through wrist-worn activity monitors and the Multimedia Activity Recall for Children and Adults. Dietary intake will be assessed using the Australian Eating Survey food frequency questionnaire. The primary outcome will be cognitive function, assessed using the Addenbrooke's Cognitive Examination-III. Secondary outcomes include structural and functional brain measures using MRI, cerebral arterial pulse measured with diffuse optical tomography, neuroplasticity using simultaneous transcranial magnetic stimulation and electroencephalography, and electrophysiological markers of cognitive control using event-related potential and time frequency analyses. Compositional data analysis, testing for interactions between time point and compositions, will assess longitudinal associations between dependent (cognition, brain function) and independent (time-use and diet compositions) variables.

CONCLUSIONS

The ACTIVate Study will be the first to examine associations between time-use and diet compositions, cognition and brain function. Our findings will inform new avenues for multidomain interventions that may more effectively account for the co-dependence between activity and diet behaviours for dementia prevention.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from the University of South Australia's Human Research Ethics committee (202639). Findings will be disseminated through peer-reviewed manuscripts, conference presentations, targeted media releases and community engagement events.

TRIAL REGISTRATION NUMBER

Australia New Zealand Clinical Trials Registry (ACTRN12619001659190).

Impact of the Mediterranean Dietary pattern on n-3 fatty acid tissue levels-A systematic review

INTRODUCTION

The Mediterranean Diet (MedDiet) is described as a plant-based dietary pattern with adherence associated with reductions in chronic disease risk and longevity. Although the nutrient profile is diverse and complex, the MedDiet is often described as a rich source of n-3 polyunsaturated fatty acids (PUFA) derived from fish, seafood and nuts. However, whether MedDiet adherence results in appreciable increases in tissue levels of n-3 PUFAs is yet to be systematically investigated. This systematic review synthesized the literature to determine the impact of the MedDiet on n-3 PUFA tissue levels.

MATERIALS AND METHODS

Medline, Embase, Amed, and CINAHL databases were searched for studies reporting on adherence to a MedDiet and tissue levels of n-3 PUFAs. PROSPERO registration number is CRD 42020162114.

RESULTS

Twenty-two studies were included. Seven were observational studies and 15 were randomised controlled trials (RCTs). All observational studies reported a positive relationship between adherence and higher tissue n-3 PUFA levels. Two-thirds (10/15) of RCTs reported significant increases in n-3 PUFA concentrations.

DISCUSSION

MedDiet adherence is associated with higher tissue levels of n-3 PUFA. However, we report heterogeneity in the description across all MedDiet interventions.

Healthy Diet for Healthy Aging

Extending healthspan is a major public health challenge. Diet is one of the modifiable factors for preventing age-related diseases and preserving overall good health status during aging. Optimizing individuals’ intrinsic capacity, including domains in cognition, psychological, sensory function, vitality, and locomotion, has been proposed as a model of healthy aging by the World Health Organization. To better understand the relationships between a healthy diet and healthy aging, this review summarizes the recent epidemiologic and clinical data for dietary patterns that have been shown to play a role in (domains of) healthy aging. Regardless of priori or posteriori dietary patterns, it appears that dietary patterns centered on plant-based foods have a beneficial role in (domains of) healthy aging. Our review identified a knowledge gap in dietary patterns and multidimensional concepts of healthy aging. More epidemiological studies should consider intrinsic capacity as an outcome measure to further our understanding of a healthy diet and multidimensional concepts of healthy aging. When a sufficient number of epidemiological studies is available, evidence can be synthesized and clinical trials can be designed to evaluate a healthy diet as a strategy for healthy aging to further our progress in translating evidence to practice and promoting healthy aging.

Effects of Nutrition on Cognitive Function in Adults with or without Cognitive Impairment: A Systematic Review of Randomized Controlled Clinical Trials

New dietary approaches for the prevention of cognitive impairment are being investigated. However, evidence from dietary interventions is mainly from food and nutrient supplement interventions, with inconsistent results and high heterogeneity between trials. We conducted a comprehensive systematic search of randomized controlled trials (RCTs) published in MEDLINE-PubMed, from January 2018 to July 2021, investigating the impact of dietary counseling, as well as food-based and dietary supplement interventions on cognitive function in adults with or without cognitive impairment. Based on the search strategy, 197 eligible publications were used for data abstraction. Finally, 61 articles were included in the analysis. There was reasonable evidence that dietary patterns, as well as food and dietary supplements improved cognitive domains or measures of brain integrity. The Mediterranean diet showed promising results, whereas the role of the DASH diet was not clear. Healthy food consumption improved cognitive function, although the quality of these studies was relatively low. The role of dietary supplements was mixed, with strong evidence of the benefits of polyphenols and combinations of nutrients, but with low evidence for PUFAs, vitamin D, specific protein, amino acids, and other types of supplements. Further well-designed RCTs are needed to guide the development of dietary approaches for the prevention of cognitive impairment.

Dietary patterns in middle age: effects on concurrent neurocognition and risk of age-related cognitive decline

Context

Diet plays a critical role in cognitive integrity and decline in older adults. However, little is known about the relationship between diet and cognitive integrity in middle age.

Objective

To investigate the relationship between dietary patterns in healthy middle-aged adults and neurocognition both in middle age and later in life.

Data Sources

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, the following electronic databases were searched: Web of Science, Scopus, PubMed, and PsychInfo.

Data Extraction

Data from eligible articles was extracted by 2 reviewers.

Data Analysis

Articles included in the systematic review were synthesized (based on the synthesis without meta-analysis reporting guidelines) and assessed for quality (using the Joanna Briggs Institute checklist for randomized controlled trials, cohort studies, and cross-sectional studies) by 2 reviewers.

Results

Of 1558 studies identified, 34 met the eligibility criteria for inclusion. These comprised 9 cross-sectional studies, 23 longitudinal or prospective cohort studies, and 2 randomized controlled trials. Findings were mixed, with some studies reporting a significant positive relationship between adherence to various “healthy” dietary patterns and neurocognition, but others reporting no such relationship.

Conclusion

This systematic review demonstrated that adherence to the Mediterranean diet and other healthy dietary patterns in middle age can protect neurocognition later in life.

Systematic Review Registration

PROSPERO registration no. CRD42020153179.

The Association between Healthy Diet and Burnout Symptoms among Finnish Municipal Employees

Background: Burnout is an undesirable mental condition, which may have a negative impact on individuals’ health and work ability. This study aimed to evaluate the relationship between diet and burnout symptoms among female public sector employees. Methods: A cross-sectional study was conducted in 2015 among 630 female employees from 10 municipal work units of the city of Pori, Finland. Burnout symptoms were assessed with the Bergen Burnout Indicator (BBI). The consumption of food items was determined using the food frequency questionnaire (FFQ). The main food groups were categorized into healthy and unhealthy foods based on the Nordic Nutrition Recommendations for a healthy and balanced diet. Results: In multivariate linear regression analysis, consumption of healthy food items had an inverse relationship with the severity of burnout symptoms independently of age, education years, physical activity, and depressive symptoms. De-tailed analysis revealed that subjects with lower BBI score consumed more often low-fat dairy produce, vegetables, fruit and berries, vegetable food, and white meat. Conclusions: Frequent consumption of healthy food items is associated with low level of burnout symptoms. Our results emphasize the importance of diverse and balanced healthy diet to promote work well-being.

Short-term effects of a Mediterranean-style dietary pattern on cognition and mental well-being: a systematic review of clinical trials

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.

Adherence to a Mediterranean diet and health-related quality of life: a cross-sectional analysis of overweight and obese middle-aged and older adults with and without type 2 diabetes mellitus

The relationship between adherence to a Mediterranean diet (MedDiet) and health-related quality of life (HRQoL) is unclear, particularly in vulnerable older adults. This cross-sectional analysis explored the association between adherence to a MedDiet and subscales of HRQoL in two independent cohorts of overweight and obese middle-aged to older adults with and without type 2 diabetes mellitus (T2DM). Both cohorts were community-dwelling (T2DM aged ≥ 50 years; non-T2DM aged ≥ 60 years) with a BMI ≥ 25 kg/m2. Adherence to a MedDiet was assessed using the Mediterranean Diet Adherence Screener, and HRQoL was determined using the 36-item short-form health survey. Multiple regression analysis was used to examine the association between adherence to a MedDiet and HRQoL subscales. A total of 152 middle-aged to older adults were included (T2DM: n 87, 71·2 (sd 8·2) years, BMI: 29·5 (sd 5·9) kg/m2; non-T2DM: n 65, 68·7 (sd 5·6) years, BMI: 33·7 (sd 4·9) kg/m2). Mean adherence scores for the entire cohort were 5·3 (sd 2·2) (T2DM cohort: 5·6(sd 2·3); non-T2DM cohort: 4·9 (sd 2·0)). In the adjusted model, using pooled data from both study cohorts, adherence to a MedDiet was significantly associated with the general health subscale of HRQoL (β = 0·223; 95 % CI 0·006, 0·044; P = 0·001). Similar findings were also observed in the T2DM cohort (β = 0·280; 95 % CI 0·007, 0·054; P = 0·001). However, no additional significant associations between adherence to a MedDiet and HRQoL subscales were observed. We showed that adherence to a MedDiet was positively associated with the general health subscale of HRQoL in middle-aged to older adults with T2DM. However, larger longitudinal data in older adults with a wider range of adherence scores, particularly higher adherence, are required to better understand the direction of this relationship.

Dietary Diversity and Healthy Aging: A Prospective Study

Population aging is a global phenomenon. The present study determined the effects of dietary diversity score (DDS) and food consumption on healthy aging. A subset of the data of the China Health and Nutrition Survey was utilized in this study. DDSs were calculated using the dietary data collected in the years 2009 and 2011. A healthy aging score (HAS) was calculated by summing the standardized scores on physical functional limitation, comorbidity, cognitive function, and psychological stress based on the data collected in the year 2015, with a lower HAS indicating a healthier aging process. Life quality was self-reported in the year 2015. This study found that DDS was inversely associated with HAS (T3 vs. T1: β −0.16, 95%CI −0.20 to −0.11, p-trend <0.001). The consumption of meat and poultry, aquatic products, and fruits was inversely associated with HAS, and participants in the highest tertile of staple foods consumption had a higher HAS than those in the lowest tertile. HAS was inversely associated with good self-reported life quality and positively associated with bad life quality. In conclusion, food consumption may influence the aging process, and adherence to a diverse diet is associated with a healthier aging process in elderly people.

Understanding the Self-Perceived Barriers and Enablers toward Adopting a Mediterranean Diet in Australia: An Application of the Theory of Planned Behaviour Framework

The transferability of a Mediterranean diet (MedDiet) in non-Mediterranean populations is appealing. However, little is known about the perceived enablers or barriers toward adherence, particularly in Australia. This study aimed to investigate the perceived beliefs, barriers, and enablers toward adherence to a MedDiet in Australian adults. Barriers and enablers were assessed using a self-administered online questionnaire, which included questions aligned with the Theory of Planned Behaviour (TPB). The survey was completed by n = 606 participants. Barriers and enablers toward adherence to MedDiet were grouped under the three core constructs of the TPB: attitudes (suitability, taste, restrictive, food waste); social norms (food culture); and perceived behavioural control (PBC) (motivation, affordability, time/effort, food access, knowledge, food outlets, natural conditions, cooking skills). PBC emerged as the most prominent construct influencing intention to follow a MedDiet. Perceived health benefits (n = 445; 76.5%) and improved diet quality (n = 224; 38.5%) were identified as major advantages. In contrast, dietary adherence (n = 147; 39.7%) was perceived as an important disadvantage. Future MedDiet interventions, in both research and clinical settings, should consider adopting strategies aimed at improving self-efficacy to reduce self-perceived barriers and facilitate dietary adherence.

An Almond-Based Low Carbohydrate Diet Improves Depression and Glycometabolism in Patients with Type 2 Diabetes through Modulating Gut Microbiota and GLP-1: A Randomized Controlled Trial

Background: Alow carbohydrate diet (LCD) is more beneficial for the glycometabolism in type 2 diabetes (T2DM) and may be effective in reducing depression. Almond, which is a common nut, has been shown to effectively improve hyperglycemia and depression symptoms. This study aimed to determine the effect of an almond-based LCD (a-LCD) on depression and glycometabolism, as well as gut microbiota and fasting glucagon-like peptide 1 (GLP-1) in patients with T2DM. Methods: This was a randomized controlled trial which compared an a-LCD with a low-fat diet (LFD). Forty-five participants with T2DM at a diabetes club and the Endocrine Division of the First and Second Affiliated Hospital of Soochow University between December 2018 to December 2019 completed each dietary intervention for 3 months, including 22 in the a-LCD group and 23 in the LFD group. The indicators for depression and biochemical indicators including glycosylated hemoglobin (HbA1c), gut microbiota, and GLP-1 concentration were assessed at the baseline and third month and compared between the two groups. Results: A-LCD significantly improved depression and HbA1c (p < 0.01). Meanwhile, a-LCD significantly increased the short chain fatty acid (SCFAs)-producing bacteria Roseburia, Ruminococcus and Eubacterium. The GLP-1 concentration in the a-LCD group was higher than that in the LFD group (p < 0.05). Conclusions: A-LCD could exert a beneficial effect on depression and glycometabolism in patients with T2DM. We speculate that the role of a-LCD in improving depression in patients with T2DM may be associated with it stimulating the growth of SCFAs-producing bacteria, increasing SCFAs production and GPR43 activation, and further maintaining GLP-1 secretion. In future studies, the SCFAs and GPR43 activation should be further examined.

Improving diet for psychiatric patients : High potential benefits and evidence for safety

BACKGROUND

Psychonutrition, i.e. the impact of diet on mental health, is an emerging field of psychiatry.

OBJECTIVE

The purpose of the present letter was to highlight recent findings in the field to guide nutritional interventions in psychiatry.

METHOD

An overview of the most recent meta-analyses in the field of psychonutrition in severe mental disorders has been carried out.

RESULTS

The Mediterranean diet showed the best evidence for effectiveness in diminishing the incidence of depressive symptomatology Complementary agents were found to be associated with lower depression levels (even in psychiatric populations): omegas 3 fatty acids, vitamin D, methylfolate and S-adenosylmethionine, all being found in high rates in the Mediterranean diet. The Healthy Eating Index (HEI) has also been found to be associated with lower depression. Moreover, major depression has been associated with inflammatory disturbances and a diet with a low Dietary Inflammatory Index has also been shown to be associated with lower depression. These effects may be mediated by microbiota modifications and probiotic supplementation has been recently shown to be effective in the treatment of depression. A high protein diet may also be particularly useful in psychiatry. The high protein diet has shown effectiveness in weight loss and increasing satiety with no evidence for deleterious effects in subjects without chronic conditions like renal failure, diabetes or cardiovascular disease. A reduction of 20% of calorific intake +/- intermittent fasting (i.e. fasting for 12 to 16 h per day) may also improve microbiota and therefore psychiatric conditions.

CONCLUSION

In light of these findings, diet modifications appear to be an underutilized tool with which to improve the mental and physical health of psychiatric patients.

Do nonpharmacological interventions prevent cognitive decline? a systematic review and meta-analysis

At present, prevention is particularly important when there is no effective treatment for cognitive decline. Since the adverse events of pharmacological interventions counterbalance the benefits, nonpharmacological approaches seem desirable to prevent cognitive decline. To our knowledge, no meta-analyses have been published on nonpharmacological interventions preventing cognitive decline. To investigate whether nonpharmacological interventions play a role in preventing cognitive decline among older people, we searched related trials up to March 31, 2019, in MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials (CENTRAL), ClinicalTrials and the Cochrane library databases. Randomized controlled trials (RCTs) were included if they enrolled participants older than 60 years of age who had a risk of cognitive decline, and the interventions were nonpharmacological. Two reviewers independently extracted data and assessed study quality. The Grading of Recommendations Assessment Development and Evaluation (GRADE) approach was used to rate the quality of evidence. Heterogeneity was quantified with I2. Subgroup analysis and meta-regression were used to research the sources of heterogeneity. Influence analyses were used to detect and remove extreme effect sizes (outliers) in our meta-analysis. Publication bias was assessed with funnel plots and Egger test. Primary outcomes were the incidence of mild cognitive impairment (MCI) or dementia and Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-Cog) scores. Second outcomes were activities of daily living (ADL) and Mini-Mental State Examination (MMSE) scores. A total of 22 studies with 13,264 participants were identified for analysis. In terms of prevention, nonpharmacological interventions appeared to be more effective than control conditions, as assessed by the incidence of MCI or dementia (RR, 0.73; CI, 0.55-0.96; moderate-certainty evidence), while the results of ADAS-Cog suggested no significant differences between two groups (MD, -0.69; CI, -1.52-0.14; very low-certainty evidence). Second outcomes revealed a significant improvement from nonpharmacological interventions versus control in terms of the change in ADL (MD, 0.73; CI, 0.65-0.80) and MMSE scores (posttreatment scores: MD, 0.25; CI, 0.02-0.47; difference scores: MD, 0.59, CI, 0.29-0.88). Univariable meta-regression showed association between lower case of MCI or dementia and two subgroup factors (P = 0.013 for sample size; P = 0.037 for area). Multiple meta-regression suggested that these four subgroup factors were not associated with decreased incidence of MCI (P > 0.05 for interaction). The Naive RR estimate was calculated as 0.73. When the three studies that detected by outlier and influence analysis were left out, the Robust RR was 0.66. In conclusion, nonpharmacological therapy could have an indicative role in reducing the case of MCI or dementia. However, given the heterogeneity of the included RCTs, more preregistered trials are needed that explicitly examine the association between nonpharmacological therapy and cognitive decline prevention, and consider relevant moderators.

Translation of a Mediterranean-Style Diet into the Australian Dietary Guidelines: A Nutritional, Ecological and Environmental Perspective

A Mediterranean diet (MedDiet) has been widely investigated and promoted as one of the 'healthiest' dietary patterns with respect to reductions in chronic disease risk and longevity. Moreover, it also emphasizes a plant-based dietary pattern consistent with an environmentally sustainable healthy reference diet conveyed by the EAT-Lancet Commission report. Nevertheless, the MedDiet does not exclude, but rather moderates consumption of animal-based foods, and therefore has emerged as a dietary pattern that could address both health and environmental concerns. However, whether non-Mediterranean countries such as Australia can adhere to such dietary principles is less clear. In this narrative review, we present evidence from eight randomized control trials conducted in Australia which demonstrates impressive and sustained adherence to a MedDiet intervention. However, we also report heterogeneity in the dietary protocols and prescriptive interpretation of a MedDiet across all studies presented in this review, making interpretations of the efficacy and adherence challenging. Based on the observable health benefits, translating key dietary elements of a Mediterranean-style diet within the Australian population remains attractive. However, adapting or modernizing traditional dietary patterns to satisfy the population's nutritional requirements and/or acceptability warrants further exploration.

A Mediterranean Diet with Fresh, Lean Pork Improves Processing Speed and Mood: Cognitive Findings from the MedPork Randomised Controlled Trial

BACKGROUND

The Mediterranean diet may be capable of improving cognitive function. However, the red meat restrictions of the diet could impact long-term adherence in Western populations. The current study therefore examined the cognitive effects of a Mediterranean diet with additional red meat.

METHODS

A 24-week parallel crossover design compared a Mediterranean diet with 2-3 weekly servings of fresh, lean pork (MedPork) and a low-fat (LF) control diet. Thirty-five participants aged between 45 and 80 years and at risk of cardiovascular disease followed each intervention for 8 weeks, separated by an 8-week washout period. Cognitive function was assessed using the Cambridge Neuropsychological Test Automated Battery. Psychological well-being was measured through the SF-36 Health Survey and mood was measured using the Profile of Mood States (POMS).

RESULTS

During the MedPork intervention, participants consumed an average of 3 weekly servings of fresh pork. Compared to LF, the MedPork intervention led to higher processing speed performance (p = 0.01) and emotional role functioning (p = 0.03). No other significant differences were observed between diets.

CONCLUSION

Our findings indicate that a Mediterranean diet inclusive of fresh, lean pork can be adhered to by an older non-Mediterranean population while leading to positive cognitive outcomes.