Adherence to the Mediterranean and MIND diets is associated with better cognition in healthy seniors but not in MCI or AD

Association of Adherence to a MIND-Style Diet With the Risk of Cognitive Impairment and Decline in the REGARDS Cohort

BACKGROUND AND OBJECTIVES

Diet may influence the development of cognitive impairment and affect cognitive decline, but whether this relationship varies between Black American and White American people is unclear. This study examined the association of Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) and incident cognitive impairment and cognitive trajectories in a biracial prospective cohort study.

METHODS

Using data derived from the Food Frequency Questionnaire in the REasons for Geographic and Racial Differences in Stroke study, we compared MIND diet adherence with incident cognitive impairment and cognitive trajectory in Black participants and White participants. Logistic regression was used to model MIND diet score (continuous variable and using tertiles) and incident cognitive impairment after adjusting for age, sex, race, region, education, income, total energy, hypertension history, dyslipidemia, diabetes, estimated glomerular filtration rate, ischemic heart conditions, atrial fibrillation, and lifestyle factors including sedentary, obesity, and smoking. Mixed-effects models were used to examine the association between cognitive trajectory and MIND diet adherence.

RESULTS

Dietary data to calculate the MIND diet score and cognitive data were available on 14,145 participants with a mean age of 64 years (SD 9.0 years) that was 56.7% female. Greater MIND diet adherence was associated with a decreased incidence of cognitive impairment (odds ratio [OR] 0.96, 95% CI 0.93-0.99, p = 0.02) after adjusting for all covariates. In the fully adjusted model, greater MIND diet adherence was associated with decreased risk of cognitive impairment in female participants (OR 0.92, 95% CI 0.89-0.96, p < 0.001) but not in male participants (OR 1.01, 95% CI 0.97-1.06, p = 0.64). In all models, greater MIND diet adherence was associated with decreased risk of cognitive decline. MIND diet adherence was a better predictor of cognitive decline in Black participants (β = 0.04, SE = 0.007, p < 0.001) than in White participants (β = 0.03, SE = 0.004, p < 0.001).

DISCUSSION

Greater MIND diet adherence was associated with decreased risk of cognitive impairment in female participants but not male participants, with no difference between Black participants and White participants. However, MIND diet adherence was a better predictor of cognitive trajectory in Black participants than in White participants.

Association between Mediterranean diet and dementia and Alzheimer disease: a systematic review with meta-analysis

BACKGROUND

Dementia affects 5-8% of the population aged over 65 years (~50 million worldwide). Several factors are associated with increased risk, including diet. The Mediterranean diet (MedDiet) has shown potential protective effects against several chronic diseases.

AIMS

This systematic review with meta-analysis aim was to assess the association between adherence to the MedDiet and the risk of dementia in the elderly.

METHODS

PRISMA-2020 guidelines were followed. PubMed/MEDLINE and Scopus were searched on 17 July 2023. The Newcastle-Ottawa Scale tool was used to assess the risk of bias. The protocol was pre-registered in PROSPERO (registration number: CRD 42023444368). Heterogeneity was assessed using the I2 test. Publication bias was assessed by visual inspection of the funnel plot and by Egger's regression asymmetry test. The final effect size was reported as OR or HR, depending on the study design of the included studies.

RESULTS

Out of 682 records, 21 were included in the analysis. The pooled OR was 0.89 (95% CI = 0.84-0.94) based on 65,955 participants (I2 = 69.94). When only cohort studies were included, HR was 0.84 (95% CI = 0.76-0.94) based on 55,205 participants (I2 = 89.70). When only Alzheimer Disease was considered OR was 0.73 (95% CI = 0.62-0.85) based on 38,292 participants (I2 = 63.85).

DISCUSSION

Despite the relatively low risk reduction associated with higher adherence to MedDiet among elderly, it should be considered that this population is the most affected.

CONCLUSIONS

Adherence to MedDiet could be an effective non-pharmacological measure to reduce the burden of dementia, even among elderly.

The Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) Diet for the Aging Brain: A Systematic Review

The Mediterranean-Dietary Approaches to Stop Hypertension Intervention for Neurodegenerative Delay (MIND) diet seems a promising approach to preserve brain function during aging. Previous systematic reviews have demonstrated benefits of the MIND diet for cognition and dementia, though an update is needed. Additionally, other outcomes relevant to brain aging have not been summarized. Therefore, this systematic review aims to give an up-to-date and complete overview on human studies that examined the MIND diet in relation to brain aging outcomes in adults aged ≥40 y. Ovid Medline, Web of Science core collection, and Scopus were searched up to July 25, 2023. Study quality was assessed using the Newcastle-Ottawa Scale and the Cochrane Risk-of-Bias tool. We included 40 articles, of which 32 were unique cohorts. Higher MIND diet adherence was protective of dementia in 7 of 10 cohorts. Additionally, positive associations were demonstrated in 3 of 4 cohorts for global cognition and 4 of 6 cohorts for episodic memory. The protective effects of the MIND diet on cognitive decline are less apparent, with only 2 of 7 longitudinal cohorts demonstrating positive associations for global decline and 1 of 6 for episodic memory decline. For other brain outcomes (domain-specific cognition, cognitive impairments, Parkinson's disease, brain volume, and pathology), results were mixed or only few studies had been performed. Many of the cohorts demonstrating protective associations were of North American origin, raising the question if the most favorable diet for healthy brain aging is population-dependent. In conclusion, this systematic review provides observational evidence for protective associations between the MIND diet and global cognition and dementia risk, but evidence for other brain outcomes remains mixed and/or limited. The MIND diet may be the preferred diet for healthy brain aging in North American populations, though evidence for other populations seems less conclusive. This review was registered at PROSPERO as CRD42022254625.

Effect of MIND diet on cognitive function in elderly: a narrative review with emphasis on bioactive food ingredients

As the world becomes a super-aged society, cognitive decline is public health problems that are increasing rapidly. A healthy diet has great potential for maintaining cognitive health. A diet that could delay the onset of neurodegenerative diseases has been developed: the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet, a hybrid form of the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet. In this review, the effects of the MIND diet on improving cognitive function, including memory, are summarized. In most studies, the higher the adherence to the MIND diet, the higher the cognitive function evaluation score, and the lower the incidence of dementia. This is because of the anti-inflammatory and antioxidant effects of the major nutritional components of the MIND diet: folate, carotenoids, polyphenols, and polyunsaturated fatty acids. Adherence to the MIND diet, containing various bioactive food ingredients, is related to cognitive improvement in the elderly population.

Dietary Patterns and Alzheimer's Disease: An Updated Review Linking Nutrition to Neuroscience

Alzheimer's disease (AD) is a growing concern for the aging population worldwide. With no current cure or reliable treatments available for AD, prevention is an important and growing area of research. A range of lifestyle and dietary patterns have been studied to identify the most effective preventive lifestyle changes against AD and related dementia (ADRD) pathology. Of these, the most studied dietary patterns are the Mediterranean, DASH, MIND, ketogenic, and modified Mediterranean-ketogenic diets. However, there are discrepancies in the reported benefits among studies examining these dietary patterns. We herein compile a narrative/literature review of existing clinical evidence on the association of these patterns with ADRD symptomology and contemplate their preventive/ameliorative effects on ADRD neuropathology in various clinical milieus. By and large, plant-based dietary patterns have been found to be relatively consistently and positively correlated with preventing and reducing the odds of ADRD. These impacts stem not only from the direct impact of specific dietary components within these patterns on the brain but also from indirect effects through decreasing the deleterious effects of ADRD risk factors, such as diabetes, obesity, and cardiovascular diseases. Importantly, other psychosocial factors influence dietary intake, such as the social connection, which may directly influence diet and lifestyle, thereby also impacting ADRD risk. To this end, prospective research on ADRD should include a holistic approach, including psychosocial considerations.

The Role of Diet in Regulation of Macrophages Functioning

The great importance of diet for health and high life-expectancy is established. The impact of nutrients on immune system is a point of growing research interest. Recent studies have found pro- and anti-inflammatory properties of some diet patterns and nutrients that can be used from the bench to the bedside for chronic low-grade inflammatory status correction. In this regard, the assessment of potential effects of nutrition on macrophage differentiation, proliferation, and functioning in health and disease is highly demanded. In this review, we present current data on the effects of nutrients on the macrophage functioning.

Are dietary patterns becoming more processed? The effects of different dietary patterns on cognition: A review

Background: Identifying dietary patterns that promote healthy aging has become increasingly important due to changes in food processing and consumption of processed foods. Recently, the effects of these foods and unhealthy dietary patterns on cognitive function have become more widely recognized. Aim: The aim of this review is to discuss the association between various dietary patterns and cognition in older age, while also highlighting growing evidence that ultra processed food (UPF) may negatively impact healthy aging. Methods: We have performed a non-systematic literature review searches in Google Scholar electronic database with pre-defined terms relating to UPF, diet, dietary patterns, cognition and ageing. Results: The most prevalent diets in the literature include the Western, Mediterranean, Dietary Approach to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurogenerative Delay (MIND), Japanese, Nordic, and plant-based diets. Based on the findings, higher intakes of fresh fruit and vegetables, wholegrains and oily fish are common components of dietary patterns that are positively associated with better cognitive function. In contrast, the characteristics of a Western style dietary pattern, consisting of high amounts of UPF's, are increasing in many countries even where the staple dietary pattern was identified as healthy (i.e. Japan). Conclusion: The consumption of UPF, classified by the NOVA food classification system as industrially manufactured foods containing high levels of starches, vegetable oils, sugar, emulsifiers, and foods additives, has a negative impact on the overall nutritional quality of individual diets.

Association Between Adherence to the MIND Diet and Cognitive Performance is Affected by Income: The ELSA-Brasil Study

BACKGROUND

The relationship between the Mediterranean-DASH Diet Intervention for Neurodegenerative Delay (MIND) diet and cognition has not been widely investigated in low- to middle-income countries. We investigated the relationship between MIND diet and cognition in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) baseline data.

METHODS

We included 11,788 participants. MIND diet adherence was based on the intake of 15 components according to a food frequency questionnaire. We analyzed the association between MIND diet adherence and global cognition, memory, and executive function using adjusted linear regression. We examined the interaction between income and MIND diet adherence on cognition and presented income stratified analyses.

RESULTS

MIND diet adherence was not associated with cognition in the whole sample. Income was an effect modifier of MIND adherence on global cognition (P=0.03) and executive function (P<0.001). For participants with high income, greater adherence was associated with better executive function [β=0.015, 95% confidence interval (CI)=0.002; 0.028, P=0.025]; while for participants with low income, greater adherence was associated with lower global cognition (β=-0.020, 95% CI=-0.036; -0.005, P=0.010) and executive function (β=-0.023, 95% CI=-0.039; -0.007, P=0.004). Adherence to the MIND diet was higher among participants with high income (P<0.001).

CONCLUSION

For high-income participants, greater adherence was associated with better cognitive performance; for low-income participants, greater adherence was associated with lower cognitive performance.

Alzheimer's Disease, Mild Cognitive Impairment and Mediterranean Diet. A Systematic Review and Dose-Response Meta-Analysis

Alzheimer’s Disease (AD) is a pathology with increasing prevalence in the context of a more long-lived society and it is the first cause of dementia in western countries. It is important to investigate factors that can be protective and may influence its development, in order to act on them trying to reduce AD incidence and its progression. The aim of this study was to conduct a systematic review and meta-analysis to determine the effects of a higher adherence to Mediterranean diet (MD) on Mild Cognitive Impairment (MCI) and AD. A literature search in PubMed, The Cochrane Library Plus and Scopus was conducted, selecting articles that analyzed associations between MD adherence and AD biomarkers (Volumetry assessed by MRI and betamiloide and Tau deposits by PET); cognitive performance in patients at risk or presenting MCI and AD; and incidence or progression from MCI to AD. Out of the 589 studies screened, 22 studies met eligibility criteria for the systematic review and qualitative synthesis. Finally, 11 studies were included in the meta-analysis (12,458 participants). Higher adherence to MD was associated with a significantly lower risk of MCI (RR = 0.91, 95%CI = 0.85–0.97) and lower risk of AD (RR = 0.89, 95% CI = 0.84–0.93). Our results enhance the importance of taking health-promoting lifestyle measures like following Mediterranean dietary patterns in order to reduce AD risk.

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.

MIND diet and cognitive performance in older adults: a systematic review

Cognitive decline is a rapidly increasing public health concern. A healthy diet has potential in preserving brain and maintaining cognitive health. This systematic review was designed to evaluate the relationship between Mediterranean-DASH diet intervention for neurodegenerative delay (MIND) diet and cognitive functioning in older adults. PubMed, SCOPUS, Embase, Cochrane Library, and Google Scholar databases were searched to extract original studies on humans published until July 2020, without date restrictions. Articles that evaluated the association between MIND diet and cognitive performance in older adults were included. Duplicated and irrelevant studies were screened out and data were obtained through critical analysis. Quality of the articles and risk of bias was assessed by Newcastle-Ottawa and Cochrane Collaboration's quality assessment tools. Of the 135 studies retrieved, 13 articles (9 cohort, 3 cross-sectional, and 1 RCT studies) were included in the final review. All of the included studies indicated that adherence to the MIND diet was positively associated with specific domains, but not all, of cognition and global cognitive function (78% of the studies) in older adults. MIND diet was superior to other plant-rich diets including Mediterranean, Dietary Approaches to Stop Hypertension, Pro-Vegetarian and Baltic Sea diets, for improving cognition. Adherence to the MIND diet may possibly be associated with an improved cognitive function in older adults. MIND diet may be superior to other plant-rich diets for improving cognition.

The Figure Memory Test: diagnosis of memory impairment in populations with heterogeneous educational background

Diagnosis of cognitive impairment is usually difficult in low-educated individuals. The Brief Cognitive Screening Battery (BCSB) was designed as a screening tool for the evaluation of cognitive impairment in low-educated individuals, but it may also be used for evaluating individuals with high educational level.

OBJECTIVES

To perform a narrative review analyzing the origin of the BCSB, to report all studies that have used the Figure Memory Test (FMT) of the BCSB, and to demonstrate that it is a useful battery for regions where populations have heterogeneous educational background.

METHODS

We performed a search in PubMed, SciELO, and LILACS using the terms "Brief Cognitive Screening Battery" and "Brief Cognitive Battery".

RESULTS

We obtained 49 papers from PubMed, 32 from SciELO, and 28 from LILACS. After the exclusion of duplicate papers, 54 publications were obtained; five more studies were included from previous knowledge of the authors. Twenty-four papers were related to the impact of education on performance, diagnostic accuracy, cutoff scores and normative studies. The delayed recall of the FMT showed the best accuracy for the diagnosis of dementia with a cutoff score of ≤5 in different education levels. In 35 papers, the FMT of the BCSB was used in clinical studies with different settings, from outpatient memory clinics to epidemiological studies and evaluation of Amazon river basin dwelling individuals, and it was always considered to be easy to apply.

CONCLUSIONS

The FMT of the BCSB is an easy and short tool for the diagnosis of dementia in populations with heterogeneous educational background.

Adherence to Healthy Diet Can Delay Alzheimer's Diseases Development: A Systematic Review and Meta-Analysis

A healthy diet has long been indicated to be protective against Alzheimer’s diseases (AD). We carried out a systematic review and meta-analysis of published observational studies to explore the relationship between healthy and unhealthy diets and risk of ADs. We screened PubMed, Scopus, Web of Sciences, Google Scholar, Science Direct, and Embase, and screened manually to identify relevant articles published in English and non-English until Jun 2020. We classified the studied dietary patterns into two groups: healthy and unhealthy diets. The pooled weighted mean difference and 95% confidence interval (95% CI) was used to analyze the data using a random-effects model. The data were extracted manually and the preferred reporting items for systematic review and meta-analysis checklist was used to appraise the risk of bias and quality of data. Of the 1,813 articles identified, 21 met the inclusion criteria and were included in the quantitative analysis. A healthy diet was related to a lower risk of AD [odds ratio (OR): 0.45, 95% CI: 0.23 to 0.86, I²=99.7%; n=17 studies]. Moreover, high adherence to an unhealthy diet was not associated with increased risk of AD (OR: 0.99, 95% CI: 0.98 to 0.99, I²=0.0%; n=6 studies). However, the etiology of AD is uncertain and it is difficult draw conclusions about dietary healthy patterns. We concluded that adherence to a healthy diet is associated with a lower risk of AD, but were unable to find evidence that an unhealthy diet increases the risk of AD.

The Effect of Healthy Diet on Cognitive Performance Among Healthy Seniors - A Mini Review

At present, a healthy diet appears to be one of the suitable strategies in slowing down cognitive decline in the process of aging. A number of evidence-based studies confirm its efficacy, safety, and cost-effectiveness. The aim of this mini review is to evaluate and describe recent randomized clinical and cohort studies exploring the effect of healthy diet on cognitive performance among healthy seniors, as well as to update the existing information on this research issue. For these reasons, the authors reviewed full-text, peer-reviewed journal articles written in English and available in Web of Science and PubMed between September 2017 and February 2020. Altogether nine original studies were detected. The results indicate that healthy diet and healthy diet components generally have a positive impact on the enhancement of cognitive functions. Furthermore, the findings reveal that dietary patterns, as well as single nutrients might have a significant effect on specific cognitive domains, such as memory in general, episodic memory, or processing speed. It also seems that a strict adherence to the dietary patterns and a higher diet variety have a more significant effect on the improvement of cognitive functions. Nevertheless, there seem to be gender differences in dietary behavior. More recently, personalized dietary interventions started to be used in delaying cognitive decline among healthy seniors. Therefore, more randomized control trials or N-of-1 trials should be performed in this research area in order to detect the most suitable dietary pattern or nutrients, which would, together with other modifiable lifestyle factors, contribute to the improvement of quality of life of the aging population.

Foods, nutrient intakes and Mediterranean dietary pattern in midlife are not associated with reaction times: a longitudinal analysis of the UK Women’s Cohort Study

Associations between dietary factors and general cognition in the elderly have been documented; however, little is known about reaction time ability in relation to midlife diet. The present study aimed to investigate associations between reaction time and midlife dietary factors, specifically foods, nutrients and Mediterranean diet (MeDi) pattern. The UK Women’s Cohort Study collected dietary information from middle-aged women (52 (sd 9·4) years old) using a validated 217-item FFQ in 1995–1998. In 2010–2011, a sub-group of 664 participants completed online reaction time ability tests including simple reaction time (SRT) and choice reaction time; 503 participants were eligible for analysis. Participants were grouped into fast and slow groups by their median reaction time. The intake of particular foods, nutrients, adherence to the MeDi and cooking methods (roasting/baking, frying and barbecuing/grilling) were explored in relation to reaction times. We did not find any significant associations between reaction times and investigated foods, nutrients or adherence to the MeDi in adjusted models. However, consumers of roasted/baked fish and fried vegetables were associated with slower SRT (adjusted OR 1·46, 95 % CI 1·00, 2·13, P = 0·049; and adjusted OR 1·64, 95 % CI 1·12, 2·39, P = 0·010, respectively) compared with non-consumers of that particularly cooked food. Overall, our findings show no significant associations between midlife diet and reaction time ability 10–15 years later.

A Suboptimal Diet is Associated with Poorer Cognition: The NUDAD Project

Nutrition is one of the modifiable risk factors for cognitive decline and Alzheimer’s disease (AD) dementia, and is therefore highly relevant in the context of prevention. However, knowledge of dietary quality in clinical populations on the spectrum of AD dementia is lacking, therefore we studied the association between dietary quality and cognitive impairment in Alzheimer’s disease (AD) dementia, mild cognitive impairment (MCI) and controls. We included 357 participants from the NUDAD project (134 AD dementia, 90 MCI, 133 controls). We assessed adherence to dietary guidelines (components: vegetables, fruit, fibers, fish, saturated fat, trans-fat, salt, and alcohol), and cognitive performance (domains: memory, language, visuospatial functioning, attention, and executive functioning). In the total population, linear regression analyses showed a lower vegetable intake is associated with poorer global cognition, visuospatial functioning, attention and executive functioning. In AD dementia, lower total adherence to dietary guidelines and higher alcohol intake were associated with poorer memory, a lower vegetable intake with poorer global cognition and executive functioning, and a higher trans-fat intake with poorer executive functioning. In conclusion, a suboptimal diet is associated with more severely impaired cognition—this association is mostly attributable to a lower vegetable intake and is most pronounced in AD dementia.

Mediterranean and MIND Diets Containing Olive Biophenols Reduces the Prevalence of Alzheimer's Disease

The risk of Alzheimer’s disease (AD) increases with nonmodifiable conditions including age and lack of effective efficacious pharmacotherapy. During the past decades, the non-pharmacotherapy mode of treatment of dietary modification received extensive attention in AD research. In order to reduce the AD pathology and cognitive decline, various dietary patterns have been attempted including caloric restriction (CR), dietary approaches to stop hypertension (DASH), ketogenic diets (KD), Mediterranean diet (MedDi) and Mediterranean-DASH diet Intervention for Neurological Delay (MIND) diet. Higher adherence to the MedDi diet was associated with decreases in cardiovascular and neurological disorders including AD and related cognitive decline. However, another emerging healthy dietary pattern MIND diet has also been associated with slower rates of cognitive decline and significant reduction of AD rate. Olive serves as one of the building block components of MedDi and MIND diets and the exerted potential health beneficial might be suggested due to the presence of its bioactive constituents such as oleic acids and phenolic compounds (biophenols). A few trials using medical food showed an optimal result in presymptomatic or early stages of AD. The review supports the notion that MedDi and MIND diets display potential for maintaining the cognitive function as nonpharmacological agents against AD pathology and proposed preventative mechanism through the presence of olive biophenols and presents the gaps along with the future directions.