Benefits in cognitive function, blood pressure, and insulin resistance through cocoa flavanol consumption in elderly subjects with mild cognitive impairment: the Cocoa, Cognition, and Aging (CoCoA) study

Synaptic plasticity and neuroprotection: The molecular impact of flavonoids on neurodegenerative disease progression

Flavonoids are a broad family of polyphenolic chemicals that are present in a wide variety of fruits, vegetables, and medicinal plants. Because of their neuroprotective qualities, flavonoids have attracted a lot of interest. The potential of flavonoids to control synaptic plasticity-a crucial process underlying memory, learning, and cognitive function-is becoming more and more clear. Dysregulation of synaptic plasticity is a feature of neurodegenerative diseases such as amyotrophic lateral sclerosis (0.4 %), Parkinson's (1-2 %), Alzheimer's (5-7 %), and Huntington's ((0.2 %)). This review discusses the molecular mechanisms via which flavonoids influence synaptic plasticity as well as their therapeutic potential in neurodegenerative diseases. Flavonoids modulate key signaling pathways such as MAPK/ERK and PI3K/Akt/mTOR to support neuroprotection, synaptic plasticity, and neuronal health, while also influencing neurotrophic factors (BDNF, NGF) and their receptors (TrkB, TrkA). They regulate neurotransmitter receptors like GABA, AMPA, and NMDA to balance excitatory and inhibitory transmission, and exert antioxidant effects via the Nrf2-ARE pathway and anti-inflammatory actions by inhibiting NF-κB signaling, highlighting their potential for treating neurodegenerative diseases. These varied reactions support the preservation of synapse function and neuronal integrity in the face of neurodegenerative insults. Flavonoids can reduce the symptoms of neurodegeneration, prevent synaptic loss, and enhance cognitive function, according to experimental studies. However, there are still obstacles to using these findings in clinical settings, such as limited bioavailability and the need for consistent dose. The focus of future research should be on improving flavonoid delivery systems and combining them with conventional medications.

Flavonoids and Alzheimer's disease: reviewing the evidence for neuroprotective potential

Neurodegeneration, which manifests as several chronic and incurable diseases, is an age-related condition that affects the central nervous system (CNS) and poses a significant threat to the public's health for the elderly. Recent decades have experienced an alarming increase in the incidence of neurodegenerative disorders (NDDs), a severe public health issue due to the ongoing development of people living in modern civilizations. Alzheimer's disease (AD) is a leading trigger of age-related dementia. Currently, there are no efficient therapeutics to delay, stop, or reverse the disease's course development. Several studies found that dietary bioactive phytochemicals, primarily flavonoids, influence the pathophysiological processes underlying AD. Flavonoids work well as a supplement to manufactured therapies for NDDs. Flavonoids are effective in complementing synthetic approaches to treat NDDs. They are biologically active phytochemicals with promising pharmacological activities, for instance, antiviral, anti-allergic, antiplatelet, anti-inflammatory, antitumor, anti-apoptotic, and antioxidant effects. The production of nitric oxide (NO), tumor necrosis factor (TNF-α), and oxidative stress (OS) are downregulated by flavonoids, which slow the course of AD. Hence, this research turned from preclinical evidence to feasible clinical applications to develop newer therapeutics, focusing on the therapeutic potential of flavonoids against AD.

(Poly)phenols and brain health - beyond their antioxidant capacity

(Poly)phenols are a group of naturally occurring phytochemicals present in high amounts in plant food and beverages with various structures and activities. The impact of (poly)phenols on brain function has gained significant attention due to the growing interest in the potential benefits of these dietary bioactive molecules for cognitive health and neuroprotection. This review will therefore summarise the current knowledge related to the impact of (poly)phenols on brain health presenting evidence from both epidemiological and clinical studies. Cellular and molecular mechanisms in relation to the observed effects will also be described, including their impact on the gut microbiota through the modulation of the gut-brain axis. Although (poly)phenols have the potential to modulate the gut-brain axis regulation and influence cognitive function and decline through their interactions with gut microbiota, anti-inflammatory and antioxidant properties, further research, including randomised controlled trials and mechanistic studies, is needed to better understand the underlying mechanisms and establish causal relationships between (poly)phenol intake and brain health.

Compositional Analysis of Grape Berries: Mapping the Global Metabolism of Grapes

To characterize the nutrients and bioactive compounds in grape berries and to explore the real cause of the "French paradox" phenomenon, we performed metabolomic analysis of 66 grape varieties worldwide using liquid chromatography-tandem mass spectrometry (LC-MS). A nontargeted metabolomics approach detected a total of 4889 metabolite signals. From these, 964 bioactive and nutrient compounds were identified and quantified, including modified flavonoids, medicinal pentacyclic triterpenoids, vitamins, amino acids, lipids, etc. Interestingly, metabolic variations between varieties are not explained by geography or subspecies but can be significantly distinguished by grapes' color, even after excluding flavonoids and anthocyanins. In our analysis, we found that purple grape varieties had the highest levels of key bioactive components such as flavonoids, pentacyclic triterpenes, and polyphenols, which are thought to have a variety of health benefits such as antioxidant, anti-inflammatory, and antitumor properties, when compared to grapes of other colors. In addition, we found higher levels of vitamins in red and pink grapes, possibly explaining their role in preventing anemia and scurvy and protecting the skin. These findings may be a major factor in the greater health benefits of wines made from purple grapes. Our study provides comprehensive metabolic profiling data of grape berries that may contribute to future research on the French paradox.

Olive Oil Industry By-Products as a Novel Source of Biophenols with a Promising Role in Alzheimer Disease Prevention

This review explores the potential health benefits and applications of phenolic secoiridoids derived from olive oil by-products in the prevention of Alzheimer's disease (AD). As reviewed herein, polyphenols, such as epigallocatechin-3-gallate, epicatechin, and resveratrol, show in vitro and in vivo antioxidant, anti-inflammatory, and neuroprotective properties, and are particularly relevant in the context of AD, a leading cause of dementia globally. The olive oil industry, particularly in the Mediterranean region, produces significant amounts of waste, including leaves, pomace, and wastewater, which pose environmental challenges but also offer an untapped source of bioactive compounds. Despite promising in vitro and in vivo studies indicating that olive-derived polyphenols, such as oleuropein and hydroxytyrosol, may mitigate AD pathology, human clinical trials remain limited. The variability in extraction methods and the complex nature of AD further complicate research. Future studies should focus on standardizing the protocols and conducting robust clinical trials to fully assess the therapeutic potential of these compounds. This approach not only supports the development of new treatments for AD but also promotes environmental sustainability by valorizing olive oil industry waste.

Potential of dietary polyphenols for protection from age-related decline and neurodegeneration: a role for gut microbiota?

Many epidemiological studies have shown the beneficial effects of a largely plant-based diet, and the strong association between the consumption of a Mediterranean-type diet with healthy aging including a lower risk of cognitive decline. The Mediterranean diet is characterized by a high intake of olive oil, fruits and vegetables and is rich in dietary fiber and polyphenols - both of which have been postulated to act as important mediators of these benefits. Polyphenols are large molecules produced by plants to protect them from environmental threats and injury. When ingested by humans, as little as 5% of these molecules are absorbed in the small intestine with the majority metabolized by the gut microbiota into absorbable simple phenolic compounds. Flavan-3-ols, a type of flavonoid, contained in grapes, berries, pome fruits, tea, and cocoa have been associated with many beneficial effects on several risk factors for cardiovascular disease, cognitive function and brain regions involved in memory formation. Both preclinical and clinical studies suggest that these brain and heart benefits can be attributed to endothelial vascular effects and anti-inflammatory properties among others. More recently the gut microbiota has emerged as a potential modulator of the aging brain and intriguingly polyphenols have been shown to alter microbiota composition and be metabolized by different microbial species. However, there is a need for well controlled studies in large populations to identify predictors of response, particularly given the vast inter-individual variation of human gut microbiota.

(-)-Epicatechin metabolites as a GPER ligands: a theoretical perspective

Diet habits and nutrition quality significantly impact health and disease. Here is delve into the intricate relationship between diet habits, nutrition quality, and their direct impact on health and homeostasis. Focusing on (-)-Epicatechin, a natural flavanol found in various foods like green tea and cocoa, known for its positive effects on cardiovascular health and diabetes prevention. The investigation encompasses the absorption, metabolism, and distribution of (-)-Epicatechin in the human body, revealing a diverse array of metabolites in the circulatory system. Notably, (-)-Epicatechin demonstrates an ability to activate nitric oxide synthase (eNOS) through the G protein-coupled estrogen receptor (GPER). While the precise role of GPER and its interaction with classical estrogen receptors (ERs) remains under scrutiny, the study employs computational methods, including density functional theory, molecular docking, and molecular dynamics simulations, to assess the physicochemical properties and binding affinities of key (-)-Epicatechin metabolites with GPER. DFT analysis revealed distinct physicochemical properties among metabolites, influencing their reactivity and stability. Rigid and flexible molecular docking demonstrated varying binding affinities, with some metabolites surpassing (-)-Epicatechin. Molecular dynamics simulations highlighted potential binding pose variations, while MMGBSA analysis provided insights into the energetics of GPER-metabolite interactions. The outcomes elucidate distinct interactions, providing insights into potential molecular mechanisms underlying the effects of (-)-Epicatechin across varied biological contexts.

Flavan-3-ols and Vascular Health: Clinical Evidence and Mechanisms of Action

Cardiovascular diseases (CVDs) are one of the main causes of mortality and morbidity worldwide. A healthy diet rich in plant-derived compounds such as (poly)phenols appears to have a key role in improving cardiovascular health. Flavan-3-ols represent a subclass of (poly)phenols of great interest for their possible health benefits. In this review, we summarized the results of clinical studies on vascular outcomes of flavan-3-ol supplementation and we focused on the role of the microbiota in CVD. Clinical trials included in this review showed that supplementation with flavan-3-ols mostly derived from cocoa products significantly reduces blood pressure and improves endothelial function. Studies on catechins from green tea demonstrated better results when involving healthy individuals. From a mechanistic point of view, emerging evidence suggests that microbial metabolites may play a role in the observed effects. Their function extends beyond the previous belief of ROS scavenging activity and encompasses a direct impact on gene expression and protein function. Although flavan-3-ols appear to have effects on cardiovascular health, further studies are needed to clarify and confirm these potential benefits and the rising evidence of the potential involvement of the microbiota.

Phytonutrients in the promotion of healthspan: a new perspective

Considering a growing, aging population, the need for interventions to improve the healthspan in aging are tantamount. Diet and nutrition are important determinants of the aging trajectory. Plant-based diets that provide bioactive phytonutrients may contribute to offsetting hallmarks of aging and reducing the risk of chronic disease. Researchers now advocate moving toward a positive model of aging which focuses on the preservation of functional abilities, rather than an emphasis on the absence of disease. This narrative review discusses the modulatory effect of nutrition on aging, with an emphasis on promising phytonutrients, and their potential to influence cellular, organ and functional parameters in aging. The literature is discussed against the backdrop of a recent conceptual framework which describes vitality, intrinsic capacity and expressed capacities in aging. This aims to better elucidate the role of phytonutrients on vitality and intrinsic capacity in aging adults. Such a review contributes to this new scientific perspective-namely-how nutrition might help to preserve functional abilities in aging, rather than purely offsetting the risk of chronic disease.

Effects of Cocoa Consumption on Cardiometabolic Risk Markers: Meta-Analysis of Randomized Controlled Trials

BACKGROUND

We conducted a systematic review and meta-analysis to examine the effect of dietary intake of cocoa on anthropometric measurements, lipid and glycemic profiles, and blood pressure levels in adults, with and without comorbidities.

METHODS

The databases used were MEDLINE (PubMed), EMBASE, Web of Science, Cochrane, LILACS, and SciELO. The eligible studies were randomized clinical trials (RCTs) involving adults undergoing cocoa consumption (cocoa extract or ≥70% cocoa dark chocolate) for ≥4 weeks that evaluated at least one of the following markers: body weight, body mass index (BMI), waist/abdominal circumference, total cholesterol, LDL-c, triglycerides, HDL-c, blood glucose, glycated hemoglobin (HbA1c), and systolic and diastolic blood pressure (SBP/DBP).

RESULTS

Thirty-one studies were included, totaling 1986 participants. Cocoa consumption showed no effects on body weight, BMI, waist circumference, triglycerides, HDL-c and HbA1c. Yet, there was a reduction in total cholesterol (-8.35 mg/dL, 95% CI -14.01; -2.69 mg/dL), LDL-c (-9.47 mg/dL, 95% CI -13.75; -5.20 mg/dL), fasting blood glucose (-4.91 mg/dL, 95% CI -8.29; -1.52 mg/dL), SBP (-2.52 mmHg, 95% CI -4.17; -0.88 mmHg), and DBP (-1.58 mmHg, 95% CI -2.54; -0.62 mmHg).

CONCLUSIONS

The consumption of cocoa showed protective effects on major cardiometabolic risk markers that have a clinical impact in terms of cardiovascular risk reduction.

Cacao consumption improves passive avoidance memory impairment in a rat model of Alzheimer's disease: the role of hippocampal synaptic plasticity and oxidative stress

Introduction: Alzheimer's disease (AD) causes progressive loss of cognitive function and synaptic plasticity, which is the most common form of dementia. The present study was designed to scrutinize the effects of cacao on passive avoidance memory function and to identify the roles of hippocampal synaptic plasticity and oxidative stress in an AD rat model induced by unilateral intracerebroventricular (UICV) injection of amyloid-beta (Aβ). Methods: Oral administration of cacao (500 mg/kg/ day) was given for 2 consecutive months. A memory retention test was conducted 24 h after passive avoidance training was completed. Subsequently, the amplitude of population spike (PS) and slope of field excitatory postsynaptic potentials (fEPSPs) were assessed at hippocampal long-term potentiation (LTP) in perforant pathway-dentate gyrus (PP-DG) synapses. Moreover, total thiol group (TTG) and malondialdehyde (MDA) concentrations were evaluated in the plasma. Furthermore, compact Aβ plaques were detected in the hippocampal DG by performing Congo red staining. Results: As a result of AD induction, passive avoidance memory was impaired; also, reduced fEPSP slopes, PS amplitudes, and content of TTG, and increase in MDA levels in the rats were observed. In contrast, cacao treatment ameliorated passive avoidance memory impairment, improved hippocampal LTP impairment, modulated oxidative-antioxidative status, and delayed Aβ plaques production in AD rats. Disscussion: Conclusively, cacao alleviates Aβ-induced cognitive deficit, probably by the amelioration of hippocampal LTP impairment, modulation of oxidative-antioxidative status, and inhibition of Aβ plaque accumulation.

Mechanistic insights into the potential role of dietary polyphenols and their nanoformulation in the management of Alzheimer's disease

Alzheimer's disease (AD) is a very common neurodegenerative disorder associated with memory loss and a progressive decline in cognitive activity. The two major pathophysiological factors responsible for AD are amyloid plaques (comprising amyloid-beta aggregates) and neurofibrillary tangles (consisting of hyperphosphorylated tau protein). Polyphenols, a class of naturally occurring compounds, are immensely beneficial for the treatment or management of various disorders and illnesses. Naturally occurring sources of polyphenols include plants and plant-based foods, such as fruits, herbs, tea, vegetables, coffee, red wine, and dark chocolate. Polyphenols have unique properties, such as being the major source of anti-oxidants and possessing anti-aging and anti-cancerous properties. Currently, dietary polyphenols have become a potential therapeutic approach for the management of AD, depending on various research findings. Dietary polyphenols can be an effective strategy to tackle multifactorial events that occur with AD. For instance, naturally occurring polyphenols have been reported to exhibit neuroprotection by modulating the Aβ biogenesis pathway in AD. Many nanoformulations have been established to enhance the bioavailability of polyphenols, with nanonization being the most promising. This review comprehensively provides mechanistic insights into the neuroprotective potential of dietary polyphenols in treating AD. It also reviews the usability of dietary polyphenol as nanoformulation for AD treatment.

Association between Flavonoid Intake and Cognitive Executive Function among African American and White Adults in the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) Study

Healthy dietary patterns rich in flavonoids may benefit cognitive performance over time. Among socioeconomically disadvantaged groups, the association between flavonoid intake and measures of cognition is unclear. This study sought to identify associations between flavonoid intake and cognitive performance among Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study participants (n = 1947) across three study visits. Flavonoid intakes were assessed via two 24-h dietary recalls. Cognitive performance was assessed via the Trail Making Test (TMT)-A and TMT-B, which provide measures of attention and executive function, respectively. Mixed effects linear regression was used to model TMT scores over three study visits against visit 1 (v1) flavonoid intake, time (years from v1), and the interaction between v1 flavonoid intake and time, capturing both the cross-sectional association between flavonoid intake and time at v1 as well as the longitudinal association between v1 flavonoid intake and the change in TMT scores over time. Prior to adjustment, inverse cross-sectional associations at v1 were observed between (1) anthocyanidin intake and TMT-A scores for the overall sample and (2) total flavonoid, anthocyanidin, flavan-3-ol, flavone, and flavonol intake and TMT-B scores for the overall sample and among White adults. Only the association between anthocyanidin intake and TMT-B at v1 among White adults persisted after adjustment (for demographic characteristics such as age). One possible explanation for the few significant associations is universally low flavonoid intakes resulting from the consumption of an unhealthy dietary pattern.

Acute effects of mango leaf extract on cognitive function in healthy adults: a randomised, double-blind, placebo-controlled crossover study

Introduction

Extracts made from the leaves of the edible mango plant (Mangifera indica L., Anacardiaceae) have a long history of medicinal usage, most likely due to the presence of high levels of mangiferin, a polyphenol compound. Previous research has demonstrated that mango leaf extract (MLE) can beneficially modulate cognitive function in both animals and humans. This study aimed to assess the effects of an acute dose of 300 mg MLE (standardised to contain ≥60% mangiferin) on cognitive performance and mood in healthy adults.

Methods

In this double-blind, placebo-controlled, crossover study, 114 healthy men and women (18-43 years) received either MLE or a matched placebo at each testing visit (separated by at least 7 days). Cognitive performance (including the cognitive demand battery) and mood were measured at 30, 180, and 300 min post-dose.

Results

The results showed that, compared to placebo, the group taking MLE displayed a significant increase in serial 3 s and serial 7 s subtraction errors overall. There were no other significant effects on cognitive performance.

Discussion

The results of the current study suggest that the consumption of 300 mg MLE in the absence of an observed multitasking psychological stressor does not improve cognitive performance or mood at up to 300 min post-dose. Due to the very limited nature of the effects and since they were observed among many analyses, these findings should be treated with caution.Clinical trial registration: http://ClinicalTrials.gov, identifier [NCT05182450].

Gardenin A treatment attenuates inflammatory markers, synuclein pathology and deficits in tyrosine hydroxylase expression and improves cognitive and motor function in A53T-α-syn mice

Oxidative stress and neuroinflammation are widespread in the Parkinson's disease (PD) brain and contribute to the synaptic degradation and dopaminergic cell loss that result in cognitive impairment and motor dysfunction. The polymethoxyflavone Gardenin A (GA) has been shown to activate the NRF2-regulated antioxidant pathway and inhibit the NFkB-dependent pro-inflammatory pathway in a Drosophila model of PD. Here, we evaluate the effects of GA on A53T alpha-synuclein overexpressing (A53TSyn) mice. A53TSyn mice were treated orally for 4 weeks with 0, 25, or 100 mg/kg GA. In the fourth week, mice underwent behavioral testing and tissue was harvested for immunohistochemical analysis of tyrosine hydroxylase (TH) and phosphorylated alpha synuclein (pSyn) expression, and quantification of synaptic, antioxidant and inflammatory gene expression. Results were compared to vehicle-treated C57BL6J mice. Treatment with 100 mg/kg GA improved associative memory and decreased abnormalities in mobility and gait in A53TSyn mice. GA treatment also reduced pSyn levels in both the cortex and hippocampus and attenuated the reduction in TH expression in the striatum seen in A53Tsyn mice. Additionally, GA increased cortical expression of NRF2-regulated antioxidant genes and decreased expression of NFkB-dependent pro-inflammatory genes. GA was readily detectable in the brains of treated mice and modulated the lipid profile in the deep gray brain tissue of those animals. While the beneficial effects of GA on cognitive deficits, motor dysfunction and PD pathology are promising, future studies are needed to further fully elucidate the mechanism of action of GA, optimizing dosing and confirm these effects in other PD models.

Modifiable risk factors of cognitive frailty in community-dwelling older adults: A systematic review and meta-analysis

PURPOSE

To perform a meta-analysis identifying the modifiable risk factors of cognitive frailty in the elderly.

METHODS

We systematically searched databases including PubMed, EMBASE, China National Knowledge Infrastructure, China Science and Technology Journal Database, Wanfang Data Knowledge Service Platform from January 01, 2017 to March 26, 2022. Quantitative, original research reporting associated factors were included.

FINDINGS

7,854 records in total were identified, of which 14 articles (1 prospective, 13 cross-sectional) with 36 factors were included. Studies on cognitive frailty included 20,390 community-dwellers (≥60 years) from three countries. Meta-analysis indicated that depression [OR = 3.60, 95%CI (2.25,5.78), p < 0.01] and sleep problems [OR = 2.36, 95%CI (1.62,3.43), p < 0.01] were associated with cognitive frailty.

CONCLUSIONS

Effective interventions targeting depression and sleep problems may lower the risk of cognitive frailty in the community seniors but need further study in high-quality, prospective studies.

IMPLICATIONS FOR NURSING PRACTICE

Building on previous work, the objectives of this systematic review and meta-analysis were to explore potential modifiable risk factors for cognitive frailty in community-dwelling older adults, which is expected to throw light on the prevention of cognitive frailty.

Effect of home-based lifestyle interventions on cognition in older adults with mild cognitive impairment: a systematic review

BACKGROUND

Mild Cognitive Impairment (MCI) is frequently a precursor to dementia, affecting aspects of cognition such as language, thinking, or memory. Lifestyle interventions are increasingly studied as potential means to slow the progression from MCI to dementia.

OBJECTIVE

A systematic review was conducted to investigate the effectiveness of home-based lifestyle interventions in reducing cognitive decline in older adults with MCI.

METHODS

A systematic review of randomized controlled trials (RCTs) was conducted to identify home-based lifestyle interventions for individuals with MCI from 1980 to 2023. These interventions were either single-component or multi-component and included diet, physical activity, stress-reduction, or cognitive stimulation treatments to assess their impact on cognition. We performed a comprehensive search in the PubMed, Web of Science, Google Scholar, Embase, and MEDLINE databases.

RESULTS

From 320 abstracts, 20 (6.25%) studies met the criteria for inclusion, with five multi-component and fifteen single-component studies. Eighteen home-based lifestyle interventions for MCI patients were focused on physical activity, diet, and/or cognitive training, while two studies were identified that incorporated stress reduction training as a method to improve cognitive function. Nineteen studies reported significant improvements in cognitive performance between the experimental and control groups post-intervention for at least one aspect of cognition. Four studies reported nonsignificant improvements in cognitive function between the two groups for at least one area of cognition.

CONCLUSIONS

Home-based lifestyle interventions have the potential to improve cognition in elderly patients with MCI. However, future RCTs with larger sample sizes and longer intervention durations are needed to confirm these findings.

The Role of Dietary Ingredients in Mental Energy - A Scoping Review of Randomized Controlled Trials

Low mental energy can contribute to decreased productivity, altered life balance, decreased physical performance, and ultimately affect quality of life. As such, there is a great demand for food and beverage products that positively impact mental energy. Numerous products claim to alter mental energy making continued review of the scientific evidence critical. The objective of this study was to conduct a scoping review of randomized controlled trials to evaluate the effect of 18 dietary ingredients on mental energy outcomes in adults without severe disease. Methods: A literature search, completed using PubMed, resulted in the identification of 2261 articles, 190 of which met eligibility from initial abstract review. Full-text review was completed on the 190 studies which resulted in 101 articles that fully met eligibility for inclusion in this study. The search strategy for two ingredients did not yield any eligible studies, leaving studies for 16 ingredients that were extracted and summarized by reported significantly improved outcomes for cognition, mood and perceived feelings, and sleep assessments. The preliminary results for several dietary ingredients directionally suggested a mental energy benefit (≥20% of outcomes), including ashwagandha, chamomile, dark chocolate, ginseng, green tea, lavender, lion's mane mushroom, maca, tart cherries, turmeric, and valerian root. The results of this scoping review suggest that of the 16 dietary ingredients reviewed, 11 may be promising for further exploration on their potential benefits in supporting mental energy. Given consumer demand and market growth for food and beverage products that positively impact mental energy; continued efforts in assessment method alignment and additional evaluation in well-designed trials is warranted.KEY TEACHING POINTSOf the 16 dietary ingredients reviewed, 11 (ashwagandha, chamomile, dark chocolate, ginseng, green tea, lavender, lion's mane mushroom, maca, melatonin foods, turmeric, and valerian root) may be promising for further exploration on their potential mental energy benefits.Dark chocolate, ginseng, ashwagandha, and lion's mane mushroom were the most promising ingredients for further evaluation in the cognition domain of the ingredients evaluated.Turmeric, maca, lavendar, and ashwagandha were the most promising ingredients for further evaluation in the mood and perceived feelings domain of the ingredients evaluated.Ashwagandha, chamomile, green tea, melatonin foods, valerian root were the most promising ingredients for further evaluation in the sleep domain of the ingredients evaluated.Additional, well-designed, consistent, clinical trials and systematic reviews are warranted as the challenge of heterogeneity in mental energy study design remains.

Applications of L-Arginine in Pregnancy and Beyond: An Emerging Pharmacogenomic Approach

L-arginine is a semi-essential amino acid that plays a critical role in various physiological processes, such as protein synthesis, wound healing, immune function, and cardiovascular regulation. The use of L-arginine in pregnancy has been an emerging topic in the field of pharmacogenomics. L-arginine, an amino acid, plays a crucial role in the production of nitric oxide, which is necessary for proper placental development and fetal growth. Studies have shown that L-arginine supplementation during pregnancy can have positive effects on fetal growth, maternal blood pressure, and the prevention of preeclampsia. This emerging pharmacogenomic approach involves using genetic information to personalize L-arginine dosages for pregnant women based on their specific genetic makeup. By doing so, it may be possible to optimize the benefits of L-arginine supplementation during pregnancy and improve pregnancy outcomes. This paper emphasizes the potential applications of L-arginine in pregnancy and the use of pharmacogenomic approaches to enhance its effectiveness. Nonetheless, the emerging pharmacogenomic approach to the application of L-arginine offers exciting prospects for the development of novel therapies for a wide range of diseases.

Effect of cocoa extract supplementation on cognitive function: results from the clinic subcohort of the COSMOS trial

BACKGROUND

Some prior randomized clinical trials (RCTs) that tested the effects of cocoa extract (CE), a source of flavanols, on late-life cognition have yielded promising findings. A long-term RCT using in-person neuropsychological tests covering multiple cognitive domains may clarify the cognitive effects of CE.

OBJECTIVES

To test whether daily supplementation with CE, compared with placebo, produces better cognitive change over 2 y.

METHODS

The COcoa Supplement and Multivitamin Outcomes Study (COSMOS) is a 2 × 2 factorial RCT of CE [500 mg flavanols/d, including 80 mg (-)-epicatechin] and/or a daily multivitamin-mineral supplement for cardiovascular disease and cancer prevention among 21,442 United States adults aged ≥60 y. There were 573 participants in the clinic subcohort of COSMOS (that is, COSMOS-Clinic) who completed all cognitive tests at baseline; of these, 492 completed 2-y follow-up assessments. The primary outcome was global cognition (averaging z-scores across 11 tests). Secondary outcomes were episodic memory and executive function/attention. Repeated measures models were used to compare randomized groups.

RESULTS

Participants' mean age (standard deviation) was 69.6 (5.3); 49.2% were females. Daily supplementation with CE, compared with placebo, had no significant effect on 2-y change in global cognition {mean difference [95% confidence interval (CI)]: -0.01 (-0.08, 0.05) standard deviation units (SU)}. CE, compared with placebo, had no significant effects on 2-y change in episodic memory [mean difference (95% CI): -0.01 (-0.13, 0.10) SU] or executive function/attention [mean difference (95% CI): 0.003 (-0.07, 0.08) SU]. Subgroup analyses uncorrected for multiple-testing suggested cognitive benefits of CE supplementation, compared with placebo among those with poorer baseline diet quality.

CONCLUSIONS

Among 573 older adults who underwent repeat in-person, detailed neuropsychological assessments over 2 y, daily CE supplementation, compared with placebo, showed no overall benefits for global or domain-specific cognitive function. Possible cognitive benefits of CE among those with poorer diet quality warrant further study.

TRIAL REGISTRATION

This trial was registered at clinicaltrials.gov with identifier - NCT02422745.

Phytochemical Extract from Carica papaya Leaves and Punica granatum Seeds as Therapy Against Cognitive Impairment in a Murine Model

Mild cognitive impairment (MCI) is defined as inter-stage between normal cognitive aging and major neurocognitive disorder (MND). This state of decay is a crucial factor in treatment to prevent the progression to MND. In this study, our group developed a virtual screening process to evaluate 2568 phytochemical compounds against 5 key proteins associated with MCI and MND. As a result, two potential candidates were identified: carpaine, found in Carica papaya leaves, and punicalagin, present in Punica granatum. A model of cognitive impairment (CI) was developed in 10-month-old male Sprague Dawley rats by administering aluminum chloride (AlCl3) at a dose of 100 mg/kg/day for 30 days. After AlCl3 administration period, one of the groups received carpaine and punicalagin in a phytochemical extract (PE) by oral gavage for 30 days. Novel object recognition test (NOR) was assessed at three different time points (T1 - before CI, T2 - after CI, and T3 - after PE treatment). Glial fibrillary acidic protein (GFAP) and neurofilament light chain (NfL) were identified in the hippocampus of rats at the end of the study period. After administration of AlCl3, a reduction in discrimination index vs control rats (CI = 0.012 ± 0.08 vs Control = 0.076 ± 0.03), was observed. After phytochemical extract treatment, a significant increase in discrimination index values was observed in the PE group 0.4643 ± 0.13 vs CI group 0.012 ± 0.08. Additionally, the evaluation of immunohistochemistry showed an increase in GFAP positivity in the hippocampus of the CI groups, while a slight decrease was observed in the PE group. This work addressed a comprehensive methodology that utilized in silico tools to identify phytochemical compounds (carpaine and punicalagin) as potential candidates for affecting key proteins in CI. The phytochemical extract containing carpaine and punicalagin resulted in a trend in the decrease of GFAP expression in the hippocampus and improved recognition memory in rats with CI induced by age and AlCl3 administration.

Cocoa Extract Supplementation and Risk of Type 2 Diabetes: The Cocoa Supplement and Multivitamin Outcomes Study (COSMOS) Randomized Clinical Trial

OBJECTIVE

Observational studies have indicated that cocoa flavanol supplementation may be a promising strategy for type 2 diabetes (T2D) prevention. We aimed to directly evaluate its clinical efficacy in a large randomized clinical trial (RCT).

RESEARCH DESIGN AND METHOD

The Cocoa Supplement and Multivitamin Outcomes Study (COMSOS) was a 2 × 2 factorial RCT performed from June 2015 to December 2020 that tested cocoa extract and a multivitamin for the prevention of cardiovascular disease (CVD) and cancer. A total of 21,442 U.S. adults free of CVD and recent cancer, including 12,666 women aged ≥65 years and 8,776 men aged ≥60 years, were randomly assigned to receive cocoa extract [500 mg/day cocoa flavanols, including 80 mg (-)-epicatechin] or placebo. In this study, we included 18,381 participants without diabetes at enrollment and examined the effect of cocoa extract supplementation on incident self-reported T2D in intention-to-treat analyses.

RESULTS

During a median follow-up of 3.5 years, 801 incident T2D cases were reported. Compared with placebo, taking a cocoa extract supplement did not reduce T2D (adjusted hazard ratio 1.04, 95% CI 0.91-1.20, P = 0.58). Stratification analyses showed that the effect of cocoa extract supplementation was not significantly modified by sex, race, BMI, smoking, physical activity, dietary quality, flavanol status at baseline, or randomized multivitamin assignment.

CONCLUSIONS

Middle-aged and older adults taking a cocoa extract supplement for a median of 3.5 years did not reduce their risk of incident T2D. Further studies of cocoa extract supplementation beginning earlier in adulthood and in populations with different background diets are warranted.

Impact of multivitamin-mineral and cocoa extract on incidence of mild cognitive impairment and dementia: Results from the COcoa Supplement and Multivitamin Outcomes Study for the Mind (COSMOS-Mind)

INTRODUCTION

We assessed the effects of multivitamin-mineral and cocoa extract supplementation on incident mild cognitive impairment (MCI) and all-cause probable dementia.

METHODS

COSMOS-Mind (N = 2262), a 2 × 2 factorial, randomized-controlled clinical trial administered a telephone-based cognitive battery at baseline and annually for 3 years. Incidence rates of MCI, and separately dementia, were compared among treatment arms with proportional hazards regression.

RESULTS

Over 3 years, 110 incident MCI and 14 incident dementia cases were adjudicated. Incidence rates did not vary by assignment to multivitamin-mineral or cocoa extract (all p's ≥ 0.05); however, statistical power was low. When participants assigned to multivitamin-mineral versus placebo converted to MCI, their scores for global cognition (p = 0.03) and executive function (p < 0.001) were higher and had declined less relative to the previous year (p = 0.03 for global cognition; p = 0.004 for executive function).

DISCUSSION

Multivitamin-mineral therapy may provide cognitive resilience, countering conversion to MCI, but not significantly reduce its incidence over 3 years.

HIGHLIGHTS

Multivitamin-mineral supplementation did not reduce risks for cognitive impairment. Cocoa extract supplementation did not reduce risks for cognitive impairment. Multivitamin-mineral supplementation slowed cognitive declines for incident mild cognitive impairment.

Gardenin A improves cognitive and motor function in A53T-α-syn mice

Oxidative stress and neuroinflammation are widespread in the Parkinson's disease (PD) brain and contribute to the synaptic degradation and dopaminergic cell loss that result in cognitive impairment and motor dysfunction. The polymethoxyflavone Gardenin A (GA) has been shown to activate the NRF2-regulated antioxidant pathway and inhibit the NFkB-dependent pro-inflammatory pathway in a Drosophila model of PD. Here, we evaluate the effects of GA on A53T alpha-synuclein overexpressing (A53TSyn) mice. A53TSyn mice were treated orally for 4 weeks with 0, 25, or 100 mg/kg GA. In the fourth week, mice underwent behavioral testing and tissue was harvested for immunohistochemical analysis of tyrosine hydroxylase (TH) and phosphorylated alpha synuclein (pSyn) expression, and quantification of synaptic, antioxidant and inflammatory gene expression. Results were compared to vehicle-treated C57BL6 mice. Treatment with 100 mg/kg GA improved associative memory and decreased abnormalities in mobility and gait in A53TSyn mice. GA treatment also reduced cortical and hippocampal levels of pSyn and attenuated the reduction in TH expression in the striatum. Additionally, GA increased cortical expression of NRF2-regulated antioxidant genes and decreased expression of NFkB-dependent pro-inflammatory genes. GA was readily detectable in the brains of treated mice and modulated the lipid profile in the deep gray brain tissue of those animals. While the beneficial effects of GA on cognitive deficits, motor dysfunction and PD pathology are promising, future studies are needed to further fully elucidate the mechanism of action of GA, optimizing dosing and confirm these effects in other PD models.

Significance Statement

The polymethoxyflavone Gardenin A can improve cognitive and motor function and attenuate both increases in phosphorylated alpha synuclein and reductions in tyrosine hydroxylase expression in A53T alpha synuclein overexpressing mice. These effects may be related to activation of the NRF2-regulated antioxidant response and downregulation of NFkB-dependent inflammatory response by Gardenin A in treated animals. The study also showed excellent brain bioavailability of Gardenin A and modifications of the lipid profile, possibly through interactions between Gardenin A with the lipid bilayer, following oral administration. The study confirms neuroprotective activity of Gardenin A previously reported in toxin induced Drosophila model of Parkinson's disease.

Apple Polyphenol Extract Ameliorates Atherosclerosis and Associated Cognitive Impairment through Alleviating Neuroinflammation by Weakening TLR4 Signaling and NLRP3 Inflammasome in High-Fat/Cholesterol Diet-Fed LDLR-/- Male Mice

Although studies have supported the beneficial effects of the ingredients of apple polyphenol extract (APE), a polyphenol mixture being extracted from whole fresh apples, on neurodegenerative diseases, the role of APE in atherosclerosis-related cognitive impairment remains unclear. To clarify the role of APE in regulating cognitive dysfunction in mice with atherosclerosis and the underlying mechanisms, high-fat/cholesterol diet-fed male LDLR-/- mice were gavaged with 125 or 500 mg/(kg·bw·d) APE solution or sterile double-distilled water for consecutive 8 weeks, and age-matched C57BL/6 male mice were employed as normal control. APE intervention increased the serum concentration of high-density apolipoprotein cholesterol, improved atherosclerosis, and ameliorated cognitive function of mice by inhibiting the phosphorylation of tau protein, supporting with significantly reduced platform latency and obviously increased swimming distance in the target quadrant according to the Morris water maze test. APE intervention alleviated neuroinflammation by attenuating the activation of microglia and astrocytes and inhibiting TLR4 signaling with reduced protein expression of NF-κB, MyD88, TRIF, and IKKβ. Meanwhile, APE intervention inactivated NLRP3 inflammasome with downregulated protein expression of caspase-1, IL-18, and IL-1β. Additionally, APE intervention improved the damaged brain barrier structure by upregulating the protein expression of ZO-1 and occludin. Therefore, our research supplemented new data, supporting the potential of APE as an effective dietary bioactive ingredient to improve atherosclerosis and associated cognitive impairment.

Review of Phytochemical Potency as a Natural Anti-Helicobacter pylori and Neuroprotective Agent

Phytochemicals are plant secondary metabolites that show health benefits for humans due to their bioactivity. There is a huge variety of phytochemicals that have already been identified, and these compounds can act as antimicrobial and neuroprotection agents. Due to their anti-microbial activity and neuroprotection, several phytochemicals might have the potency to be used as natural therapeutic agents, especially for Helicobacter pylori infection and neurodegenerative disease, which have become a global health concern nowadays. According to previous research, there are some connections between H. pylori infection and neurodegenerative diseases, especially Alzheimer's disease. Hence, this comprehensive review examines different kinds of phytochemicals from natural sources as potential therapeutic agents to reduce H. pylori infection and improve neurodegenerative disease. An additional large-scale study is needed to establish the connection between H. pylori infection and neurodegenerative disease and how phytochemicals could improve this condition.

Dietary pattern, food, and nutritional supplement effects on cognitive outcomes in mild cognitive impairment: a systematic review of previous reviews

CONTEXT

Nutritional interventions may benefit cognition in people with mild cognitive impairment (MCI). However, evidence is yet to be synthesized in a way that can inform recommendations for clinical and public health settings.

OBJECTIVE

To systematically review evidence on the effect of dietary patterns, foods, and nutritional supplements on cognitive decline in individuals with MCI.

DATA SOURCES

Guided by the Preferred Reporting items for Systematic Review and Meta-Analysis Protocols 2015 statement, the Medline, EMBASE, and CINAHL databases, the JBI Database of Systematic Reviews and Implementation Reports, Cochrane Database of Systematic Reviews, and Database of Abstracts of Reviews of Effects were searched (publication years 2005 to 2020). Included studies were English-language systematic reviews and meta-analyses of randomized controlled trials and cohort studies reporting on the effectiveness of nutritional interventions on cognition of individuals with MCI.

DATA EXTRACTION

Two reviewers independently selected studies and extracted data on cognitive outcomes and adverse events. Review quality was assessed using AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews-2). Primary study overlap was managed following Cochrane Handbook guidelines.

DATA ANALYSIS

Of the 6677 records retrieved, 20 reviews were included, which, in turn, reported on 43 randomized controlled trials and 1 cohort study that, together, addressed 18 nutritional interventions. Most reviews were limited by quality and the small number of primary studies with small sample sizes. Reviews were mostly positive for B vitamins, omega-3 fatty acids, and probiotics (including 12, 11 and 4 primary studies, respectively). Souvenaid and the Mediterranean diet reduced cognitive decline or Alzheimer's disease progression in single trials with <500 participants. Findings from studies with a small number of participants suggest vitamin D, a low-carbohydrate diet, medium-chain triglycerides, blueberries, grape juice, cocoa flavanols, and Brazil nuts may improve individual cognitive subdomains, but more studies are needed.

CONCLUSIONS

Few nutritional interventions were found to convincingly improve cognition of individuals with MCI. More high-quality research in MCI populations is required to determine if nutritional treatments improve cognition and/or reduce progression to dementia.

SYSTEMATIC REVIEW REGISTRATION

Open Science Framework protocol identifier DOI:10.17605/OSF.IO/BEP2S.

Six-month intervention with wild blueberries improved speed of processing in mild cognitive decline: a double-blind, placebo-controlled, randomized clinical trial

BACKGROUND

As the sector of the population over 65y increases, cognitive decline and dementia become a public health issue. Interventions to improve brain health and thus, quality of life for older adults are needed.

OBJECTIVE

It was hypothesized that those consuming a flavonoid-rich, lyophilized wild blueberry powder would evidence improvements in cognitive performance as measured behaviorally and electrophysiologically compared to those consuming a placebo powder across a 6-month intervention period.

DESIGN

In a double-blind, randomized placebo-controlled trial, participants experiencing cognitive issues as determined by scores on the Montreal Cognitive Assessment (MoCA) were randomized to consume either wild blueberry (n  =  44) or placebo (n  =  42) powder daily for 6 months. Participants who were not experiencing any cognitive issues were included as a reference group (n = 45). Participants were tested at baseline and outcome on the Cambridge Neurological Test Automated Battery (CANTAB) and in an electrophysiological paradigm known as event-related potentials (ERP).

RESULTS

Tests of specific cognitive abilities using the CANTAB showed speed of processing not only improved in the blueberry intervention group relative to the placebo group across the 6-month intervention, but blueberries also restored speed of processing to the level of the reference group. The ERP results also showed that, relative to those consuming placebo, speed of processing improved for those in the blueberry group; this improvement was most prominent in those 75-80y.

CONCLUSIONS

Consumption of wild blueberries for six months improves cognitive aging sequelae by improving the speed of information processing in older adults.Trial registration: ClinicalTrials.gov identifier: NCT01515098.

Effects of chocolate on cognitive function in healthy adults: A systematic review and meta-analysis on clinical trials

Cognitive function is defined as performance in objective tasks that need conscious mind effort. It has been shown that consuming foods rich in flavanols causes neurobiological effects and improves learning, memory, and global cognitive function. This study aimed to investigate the impact of chronic chocolate consumption on cognitive function in healthy adults based on published trials. The PICO strategy was applied to examine the research question in this study. Researchers searched the Web of Science, Science Direct, Pubmed, Scopus, Cochrane Library, and Google Scholar databases. Related articles of randomized controlled trials that evaluated the chronic effect of chocolate on cognitive function were selected (all published from their inception to February 2021). The difference in means of the last and first measurements was the main effect measure between the control and intervention groups. For quantitative data synthesis, weighted mean difference (WMD) and 95% confidence interval (CI) were performed in the random effect model. Of the initial 340 articles identified, seven trials met the eligibility criteria. Chronic chocolate intake significantly reduced executive function time (WMD: -11.77, 95% CI: -22.49, -1.05, p = 0.03) of the participants. Further, the language and executive function (WMD: 6.38, 95% CI: 5.97, 6.80, p < 0.001) was raised by 6.38 times after the intervention with chocolate. We could not perform subgroup analysis due to insufficient trials and significant heterogeneity in some studies. It is concluded that daily consumption of cocoa may provide short and middle-term effects on young adults and make them better cognitive performance in learning, memory, and attention.

A combined DHA-rich fish oil and cocoa flavanols intervention does not improve cognition or brain structure in older adults with memory complaints: results from the CANN randomized, controlled parallel-design study

BACKGROUND

There is evidence that both omega-3 long-chain polyunsaturated fatty acids (PUFAs) (eicosapentaenoic acid [EPA] and docosahexaenoic acid [DHA]) and cocoa flavanols can improve cognitive performance in both healthy individuals and in those with memory complaints. However, their combined effect is unknown.

OBJECTIVES

To investigate the combined effect of EPA/DHA and cocoa flavanols (OM3FLAV) on cognitive performance and brain structures in older adults with memory complaints.

METHODS

A randomized placebo-controlled trial of DHA-rich fish oil (providing 1.1 g/d DHA and 0.4 g/d EPA) and a flavanol-rich dark chocolate (providing 500 mg/d flavan-3-ols) was conducted in 259 older adults with either subjective cognitive impairment or mild cognitive impairment. Participants underwent assessment at baseline, 3 mo, and 12 mo. The primary outcome was the number of false-positives on a picture recognition task from the Cognitive Drug Research computerized assessment battery. Secondary outcomes included other cognition and mood outcomes, plasma lipids, brain-derived neurotrophic factor (BDNF), and glucose levels. A subset of 110 participants underwent structural neuroimaging at baseline and at 12 mo.

RESULTS

197 participants completed the study. The combined intervention had no significant effect on any cognitive outcomes, with the exception of reaction time variability (P = 0.007), alertness (P < 0.001), and executive function (P < 0.001), with a decline in function observed in the OM3FLAV group (118.6 [SD 25.3] at baseline versus 113.3 [SD 25.4] at 12 mo for executive function) relative to the control, and an associated decrease in cortical volume (P = 0.039). Compared with the control group, OM3FLAV increased plasma HDL, total cholesterol ratio (P < 0.001), and glucose (P = 0.008) and reduced TG concentrations (P < 0.001) by 3 mo, which were sustained to 12 mo, with no effect on BDNF. Changes in plasma EPA and DHA and urinary flavonoid metabolite concentrations confirmed compliance to the intervention.

CONCLUSIONS

These results suggest that cosupplementation with ω-3 PUFAs and cocoa flavanols for 12 mo does not improve cognitive outcomes in those with cognitive impairment. This trial was registered at clinicaltrials.gov as NCT02525198.

Association of dietary flavan-3-ol intakes with plasma phenyl-γ-valerolactones: analysis from the TUDA cohort of healthy older adults

BACKGROUND

Dietary polyphenols, including flavan-3-ols (F3O), are associated with better health outcomes. The relationship of plasma phenyl-γ-valerolactones (PVLs), the products of colonic bacterial metabolism of F3O, with dietary intakes is unclear.

OBJECTIVES

To investigate whether plasma PVLs are associated with self-reported intakes of total F3O and procyanidins+(epi)catechins.

DESIGN

We measured 9 PVLs by uHPLC-MS-MS in plasma from adults (>60y) in the Trinity-Ulster-Department of Agriculture (TUDA study (2008 to 2012; n=5186) and a follow-up subset (2014 to 2018) with corresponding dietary data (n=557). Dietary (poly)phenols collected by FFQ were analyzed using Phenol-Explorer.

RESULTS

Mean (95% confidence interval [CI]) intakes were estimated as 2283 (2213, 2352) mg/d for total (poly)phenols, 674 (648, 701) for total F3O, and 152 (146, 158) for procyanidins+(epi)catechins. Two PVL metabolites were detected in plasma from the majority of participants, 5-(hydroxyphenyl)-γ-VL-sulfate (PVL1) and 5-(4'-hydroxyphenyl)-γ-VL-3'-glucuronide (PVL2). The 7 other PVLs were detectable only in 1-32% of samples. Self-reported intakes (mg/d) of F3O (r = 0.113, P = 0.017) and procyanidin+(epi)catechin (r = 0.122, P = 0.010) showed statistically significant correlations with the sum of PVL1 and PVL 2 (PVL1+2). With increasing intake quartiles (Q1-Q4), mean (95% CI) PVL1+2 increased; from 28.3 (20.8, 35.9) nmol/L in Q1 to 45.2 (37.2, 53.2) nmol/L in Q4; P = 0.025, for dietary F3O, and from 27.4 (19.1, 35.8) nmol/L in Q1 to 46.5 (38.2, 54.9) nmol/L in Q4; P = 0.020, for procyanidins+(epi)catechins.

CONCLUSIONS

Of 9 PVL metabolites investigated, 2 were detected in most samples and were weakly associated with intakes of total F3O and procyanidins+(epi)catechins. Future controlled feeding studies are required to validate plasma PVLs as biomarkers of these dietary polyphenols.

Diet and lifestyle impact the development and progression of Alzheimer's dementia

Dementia is a growing public health concern, with an estimated prevalence of 57 million adults worldwide. Alzheimer's disease (AD) accounts for 60-80% of the cases. Clinical trials testing potential drugs and neuroprotective agents have proven futile, and currently approved drugs only provide symptomatic benefits. Emerging epidemiological and clinical studies suggest that lifestyle changes, including diet and physical activity, offer an alternative therapeutic route for slowing and preventing cognitive decline and dementia. Age is the single most common risk factor for dementia, and it is associated with slowing cellular bioenergetics and metabolic processes. Therefore, a nutrient-rich diet is critical for optimal brain health. Furthermore, type 2 diabetes (T2D) is a risk factor for AD, and diets that reduce the risk of T2D may confer neuroprotection. Foods predominant in Mediterranean, MIND, and DASH diets, including fruits, leafy green vegetables, fish, nuts, and olive oil, may prevent or slow cognitive decline. The mechanisms by which these nutrients promote brain health, however, are not yet completely understood. Other dietary approaches and eating regimes, including ketogenic and intermittent fasting, are also emerging as beneficial for brain health. This review summarizes the pathophysiology, associated risk factors, and the potential neuroprotective pathways activated by several diets and eating regimes that have shown promising results in promoting brain health and preventing dementia.

Molecular Aspects of a Diet as a New Pathway in the Prevention and Treatment of Alzheimer's Disease

Alzheimer's disease is the most common cause of dementia in the world. Lack of an established pathology makes it difficult to develop suitable approaches and treatment for the disease. Besides known hallmarks, including amyloid β peptides cumulating in plaques and hyperphosphorylated tau forming NFTs, inflammation also plays an important role, with known connections to the diet. In AD, adhering to reasonable nutrition according to age-related principles is recommended. The diet should be high in neuroprotective foods, such as polyunsaturated fatty acids, antioxidants, and B vitamins. In addition, foods capable of rising BDNF should be considered because of the known profitable results of this molecule in AD. Adhering to beneficial diets might result in improvements in memory, cognition, and biomarkers and might even reduce the risk of developing AD. In this review, we discuss the effects of various diets, foods, and nutrients on brain health and possible connections to Alzheimer's disease.

Effects of a Raisin Supplement on Cognitive Performance, Quality of Life, and Functional Activities in Healthy Older Adults-Randomized Clinical Trial

The objective of this study was to evaluate the effects of consuming 50 g of raisins on cognitive performance, quality of life, and functional activities in healthy older adults. This is a parallel randomized controlled clinical trial, in which 80 subjects over 70 years of age participated. For 6 months, the intervention group (IG; n = 40) consumed 50 g of raisins per day added to their usual diet, whereas the control group (CG; n = 40) received no supplement. All variables were measured at baseline and at 6 months. Cognitive performance assessed with the Montreal Cognitive Assessment (MOCA) test shows a difference of 3.27 points (95% CI 1.59 to 4.96), p ≤ 0.001, favorable to the IG, after the intervention. Among the cognitive performances, an improvement is observed in the IG in orientation, assessed both with the MOCA test 0.49 (95% CI 0.10 to 0.87), p = 0.014, and with the Mini-Mental State Examination (MMSE) test, 0.36 (95% CI 0.02 to 0.70), p = 0.038. In visuospatial/executive capacity and in language, improvements were also observed in the IG, 1.36 (95% CI 0.77 to 1.95), p = 0.001, and 0.54 points (95% CI 0.12 to 0.96), p = 0.014, respectively. Immediate and delayed recall, assessed with the Rey Auditory Verbal Learning Test, improved in the IG. In addition, the IG showed a better quality of life and greater autonomy in instrumental activities of daily living after 6 months. No significant changes were observed in the rest of the variables analyzed. Therefore, the consumption of 50 g of raisins produces a slight improvement in cognitive performance, quality of life, and functional activities in the elderly.

Pathways to healing: Plants with therapeutic potential for neurodegenerative diseases

Some of the greatest challenges in medicine are the neurodegenerative diseases (NDs), which remain without a cure and mostly progress to death. A companion study employed a toolkit methodology to document 2001 plant species with ethnomedicinal uses for alleviating pathologies relevant to NDs, focusing on its relevance to Alzheimer's disease (AD). This study aimed to find plants with therapeutic bioactivities for a range of NDs. 1339 of the 2001 plant species were found to have a bioactivity from the literature of therapeutic relevance to NDs such as Parkinson's disease, Huntington's disease, AD, motor neurone diseases, multiple sclerosis, prion diseases, Neimann-Pick disease, glaucoma, Friedreich's ataxia and Batten disease. 43 types of bioactivities were found, such as reducing protein misfolding, neuroinflammation, oxidative stress and cell death, and promoting neurogenesis, mitochondrial biogenesis, autophagy, longevity, and anti-microbial activity. Ethno-led plant selection was more effective than random selection of plant species. Our findings indicate that ethnomedicinal plants provide a large resource of ND therapeutic potential. The extensive range of bioactivities validate the usefulness of the toolkit methodology in the mining of this data. We found that a number of the documented plants are able to modulate molecular mechanisms underlying various key ND pathologies, revealing a promising and even profound capacity to halt and reverse the processes of neurodegeneration.

The effect of grape seed procyanidins extract on cognitive function in elderly people with mild cognitive impairment: A randomized, double-blind, placebo-controlled clinical trial

Background

Procyanidins have antioxidative properties that may protect against age-related brain oxidative stress. Previous studies indicated that procyanidin-rich foods could improve cognitive function and prevent neurodegenerative diseases. This study hypothesized that grape seed procyanidins extract (GSPE) would have a favorable effect on cognitive function in elderly people with mild cognitive impairment (MCI).

Methods

A community-based, randomized, double-blind, placebo-controlled trial was conducted. Participants aged 60 years or older with MCI were randomly assigned into the GSPE group (n = 35, 320 mg/d) or placebo group (n = 36), and received capsules for 6 months. Cognitive function was assessed using the Montreal Cognitive Assessment Scale (MoCA). The change in MoCA scores between groups were tested by the time ✕ treatment interaction in mixed-design ANOVA.

Results

After 6 months of intervention, the MoCA score was higher than the baseline both in the intervention group and placebo control group, while the there was no significant difference for mean change in MoCA score from baseline between the intervention group and the placebo group (2.35 ± 3.20 vs. 1.28 ± 2.93, P = 0.192).

Conclusions

Present study showed that 6-month supplementation with GSPE did not significantly improve cognitive function in subjects with MCI. Further investigations regarding the longer-term intervention effect of procyanidins extract on mild or moderate cognitive disorders are needed.

Effects of cocoa extract and a multivitamin on cognitive function: A randomized clinical trial

INTRODUCTION

Dietary supplements are touted for cognitive protection, but supporting evidence is mixed. COSMOS-Mind tested whether daily administration of cocoa extract (containing 500 mg/day flavanols) versus placebo and a commercial multivitamin-mineral (MVM) versus placebo improved cognition in older women and men.

METHODS

COSMOS-Mind, a large randomized two-by-two factorial 3-year trial, assessed cognition by telephone at baseline and annually. The primary outcome was a global cognition composite formed from mean standardized (z) scores (relative to baseline) from individual tests, including the Telephone Interview of Cognitive Status, Word List and Story Recall, Oral Trail-Making, Verbal Fluency, Number Span, and Digit Ordering. Using intention-to-treat, the primary endpoint was change in this composite with 3 years of cocoa extract use. The pre-specified secondary endpoint was change in the composite with 3 years of MVM supplementation. Treatment effects were also examined for executive function and memory composite scores, and in pre-specified subgroups at higher risk for cognitive decline.

RESULTS

A total of 2262 participants were enrolled (mean age = 73y; 60% women; 89% non-Hispanic White), and 92% completed the baseline and at least one annual assessment. Cocoa extract had no effect on global cognition (mean z-score = 0.03, 95% CI: -0.02 to 0.08; P = .28). Daily MVM supplementation, relative to placebo, resulted in a statistically significant benefit on global cognition (mean z = 0.07, 95% CI 0.02 to 0.12; P = .007), and this effect was most pronounced in participants with a history of cardiovascular disease (no history: 0.06, 95% CI 0.01 to 0.11; history: 0.14, 95% CI -0.02 to 0.31; interaction, nominal P = .01). Multivitamin-mineral benefits were also observed for memory and executive function. The cocoa extract by MVM group interaction was not significant for any of the cognitive composites.

DISCUSSION

Cocoa extract did not benefit cognition. However, COSMOS-Mind provides the first evidence from a large, long-term, pragmatic trial to support the potential efficacy of a MVM to improve cognition in older adults. Additional work is needed to confirm these findings in a more diverse cohort and to identify mechanisms to account for MVM effects.

HIGHLIGHTS

COSMOS-Mind was a large simple pragmatic randomized clinical trial in older adults conducted by mail and telephone. The trial used a two-by-two factorial design to assess treatment effects of two different interventions within a single large study. We found no cognitive benefit of daily cocoa extract administration (containing 500 mg flavanols) for 3 years. Daily multivitamin-mineral (MVM) supplementation for 3 years improved global cognition, episodic memory, and executive function in older adults. The MVM benefit appeared to be greater for adults with cardiovascular disease.

Nonlinear relationship between glycated hemoglobin and cognitive impairment after acute mild ischemic stroke

BACKGROUND

Stroke is the second most common cause of morbidity and mortality. Even mild stroke survivors have an increased risk of cognitive impairment. Studies have been conducted on the relationship between glycated hemoglobin (HbA1c) and cognitive decline, but the findings have been inconsistent. Therefore, this study examined the link between HbA1c levels and cognitive impairment following acute mild ischemic stroke.

METHODS

Data from 311 patients with acute mild ischemic stroke admitted to Suining Central Hospital, Sichuan Province, China, from January 1, 2015, to December 31, 2018, were evaluated. Fasting venous blood was taken to assess HbA1c levels on the day after admission. Cognitive function was assessed using the Chinese version of the Montreal Cognitive Assessment Scale (MoCA) 3-6 months after stroke onset. We used a generalized additive model and smooth curve fitting (penalty spline method) to assess the nonlinear relationship between HbA1c and poststroke cognitive impairment (PSCI).

RESULTS

This study included 311 patients aged 23 to 96 years old (mean age: 67.37 ± 11.92 years), of whom 198 (63.67%) were men. Among the 311 stroke patients, 120 (38.59%) had PSCI. After adjusting for potential confounders, there was a nonlinear relationship between HbA1c and PSCI, with an inflection point of 8.2. To the left of the inflection point, the effect size, 95% confidence interval, and P value were 0.87, 0.58 to 1.31, and 0.5095, respectively; however, to the right of the inflection point, these numbers were 1.96, 1.08 to 3.58, and 0.0280.

CONCLUSION

We found a nonlinear relationship between HbA1c and PSCI. When HbA1c was greater than 8.2%, HbA1c was positively correlated with PSCI.

Anti-Inflammatory Effects of Flavonoids in Common Neurological Disorders Associated with Aging

Aging reduces homeostasis and contributes to increasing the risk of brain diseases and death. Some of the principal characteristics are chronic and low-grade inflammation, a general increase in the secretion of proinflammatory cytokines, and inflammatory markers. Aging-related diseases include focal ischemic stroke and neurodegenerative diseases such as Alzheimer's disease (AD) and Parkinson's disease (PD). Flavonoids are the most common class of polyphenols and are abundantly found in plant-based foods and beverages. A small group of individual flavonoid molecules (e.g., quercetin, epigallocatechin-3-gallate, and myricetin) has been used to explore the anti-inflammatory effect in vitro studies and in animal models of focal ischemic stroke and AD and PD, and the results show that these molecules reduce the activated neuroglia and several proinflammatory cytokines, and also, inactivate inflammation and inflammasome-related transcription factors. However, the evidence from human studies has been limited. In this review article, we highlight the evidence that individual natural molecules can modulate neuroinflammation in diverse studies from in vitro to animal models to clinical studies of focal ischemic stroke and AD and PD, and we discuss future areas of research that can help researchers to develop new therapeutic agents.

Effect of Cocoa Roasting on Chocolate Polyphenols Evolution

Cocoa and chocolate antioxidants might contribute to human health through, for instance, blood flow improvement or blood pressure and glycemia reduction, as well as cognitive function improvement. Unfortunately, polyphenol content is reduced during cocoa fermentation, drying, roasting and all the other phases involved in the chocolate production. Here, we investigated the evolution of the polyphenol content during all the different steps of chocolate production, with a special emphasis on roasting (3 different roasting cycles with 80, 100, and 130 °C as maximum temperature). Samples were followed throughout all processes by evaluating the total polyphenols content, the antioxidant power, the epicatechin content, and epicatechin mean degree of polymerization (phloroglucinol adducts method). Results showed a similar trend for total polyphenol content and antioxidant power with an unexpected bell-shaped curve: an increase followed by a decrease for the three different roasting temperatures. At the intermediate temperature (100 °C), the higher polyphenol content was found just after roasting. The epicatechin content had a trend similar to that of total polyphenol content but, interestingly, the mean degree of polymerization data had the opposite behavior with some deviation in the case of the highest temperature, probably due to epicatechin degradation. It seems likely that roasting can free epicatechin from oligomers, as a consequence of oligomers remodeling.

A role for flavonoids in the prevention and/or treatment of cognitive dysfunction, learning, and memory deficits: a review of preclinical and clinical studies

OBJECTIVE

Natural food substances, due to high rates of antioxidants, antiviral and anti-inflammatory properties, have been proposed to have the potential for the prevention or treatment of cognitive deficits, learning and memory deficits and neuro inflammation. In particular, medicinal plants with rich amounts of beneficial components such as flavonoids are one of the most promising therapeutic candidates for the cognitive deficit and memory loss. Herein, we aimed to review the impact of medicinal plants with focus on flavonoids on cognitive dysfunction, learning and memory loss by considering their signaling pathways.

METHODS

We extracted 93 preclinical and clinical studies related to the effects of flavonoids on learning and memory and cognition from published papers between 2000 and 2021 in the MEDLINE/PubMed, Cochrane Library, SCOPUS, and Airiti Library databases.

RESULTS

In the preclinical studies, at least there seem to be two main neurological and biological processes in which flavonoids contribute to the improvement and/or prevention of learning, memory deficit and cognitive dysfunction: (1) Regulation of neurotransmission system and (2) Enhancement of neurogenesis, synaptic plasticity and neuronal survival.

CONCLUSION

Although useful effects of flavonoids on learning and memory in preclinical investigations have been approved, more clinical trials are required to find out whether flavonoids and/or other ingredients of plants have the potent to prevent or treat neurodegenerative disorders.

Cocoa Flavanol Supplementation and the Effect on Insulin Resistance in Females Who Are Overweight or Obese: A Randomized, Placebo-Controlled Trial

There is interest in the impact that dietary interventions can have on preventing the transition from insulin resistance to type 2 diabetes, including a suggestion that the bioactive components of cocoa may enhance fasting insulin sensitivity. However, a role for cocoa flavanols (CF) in reducing insulin resistance in the insulin-stimulated state, an important risk factor for cardiovascular disease, is unresolved. This study investigated whether CF consumption improved whole-body insulin-mediated glucose uptake ('M') in females with overweight/obesity, using a randomized, double-blinded, placebo-controlled, parallel-group design. Thirty-two premenopausal females (19-49 years; 27-35 kg·m-2) with elevated HOMA-IR (HOMA-IR >1.5) supplemented their habitual diet with two servings/day of a high-flavanol cocoa drink (HFC; 609 mg CF/serving; n = 16) or low-flavanol cocoa drink (LFC; 13 mg CF/serving; n = 16) for 4 weeks. Assessment of HOMA-IR and 'M' during a 3-h, 60 mIU insulin·m-2·min-1 euglycemic clamp was performed before and after the intervention. Data are the mean (SD). Changes to HOMA-IR (HFC -0.003 (0.57); LFC -0.0402 (0.86)) and 'M' (HFC 0.99 (7.62); LFC -1.32 (4.88) µmol·kg-1·min-1) after the intervention were not different between groups. Four weeks' consumption of ~1.2 g CF/day did not improve indices of fasting insulin sensitivity or insulin-mediated glucose uptake. A recommendation for dietary supplementation with cocoa flavanols to improve glycemic control is therefore not established.

Rationale for a Multi-Factorial Approach for the Reversal of Cognitive Decline in Alzheimer's Disease and MCI: A Review

Alzheimer's disease (AD) is a multifactorial, progressive, neurodegenerative disease typically characterized by memory loss, personality changes, and a decline in overall cognitive function. Usually manifesting in individuals over the age of 60, this is the most prevalent type of dementia and remains the fifth leading cause of death among Americans aged 65 and older. While the development of effective treatment and prevention for AD is a major healthcare goal, unfortunately, therapeutic approaches to date have yet to find a treatment plan that produces long-term cognitive improvement. Drugs that may be able to slow down the progression rate of AD are being introduced to the market; however, there has been no previous solution for preventing or reversing the disease-associated cognitive decline. Recent studies have identified several factors that contribute to the progression and severity of the disease: diet, lifestyle, stress, sleep, nutrient deficiencies, mental health, socialization, and toxins. Thus, increasing evidence supports dietary and other lifestyle changes as potentially effective ways to prevent, slow, or reverse AD progression. Studies also have demonstrated that a personalized, multi-therapeutic approach is needed to improve metabolic abnormalities and AD-associated cognitive decline. These studies suggest the effects of abnormalities, such as insulin resistance, chronic inflammation, hypovitaminosis D, hormonal deficiencies, and hyperhomocysteinemia, in the AD process. Therefore a personalized, multi-therapeutic program based on an individual's genetics and biochemistry may be preferable over a single-drug/mono-therapeutic approach. This article reviews these multi-therapeutic strategies that identify and attenuate all the risk factors specific to each affected individual. This article systematically reviews studies that have incorporated multiple strategies that target numerous factors simultaneously to reverse or treat cognitive decline. We included high-quality clinical trials and observational studies that focused on the cognitive effects of programs comprising lifestyle, physical, and mental activity, as well as nutritional aspects. Articles from PubMed Central, Scopus, and Google Scholar databases were collected, and abstracts were reviewed for relevance to the subject matter. Epidemiological, pathological, toxicological, genetic, and biochemical studies have all concluded that AD represents a complex network insufficiency. The research studies explored in this manuscript confirm the need for a multifactorial approach to target the various risk factors of AD. A single-drug approach may delay the progression of memory loss but, to date, has not prevented or reversed it. Diet, physical activity, sleep, stress, and environment all contribute to the progression of the disease, and, therefore, a multi-factorial optimization of network support and function offers a rational therapeutic strategy. Thus, a multi-therapeutic program that simultaneously targets multiple factors underlying the AD network may be more effective than a mono-therapeutic approach.

Benefits of dietary polyphenols in Alzheimer's disease

Alzheimer's disease (AD) is an irreversible progressive neurodegenerative disease affecting approximately 50 million people worldwide. It is estimated to reach 152 million by the year 2050. AD is the fifth leading cause of death among Americans age 65 and older. In spite of the significant burden the disease imposes upon patients, their families, our society, and our healthcare system, there is currently no cure for AD. The existing approved therapies only temporarily alleviate some of the disease's symptoms, but are unable to modulate the onset and/or progression of the disease. Our failure in developing a cure for AD is attributable, in part, to the multifactorial complexity underlying AD pathophysiology. Nonetheless, the lack of successful pharmacological approaches has led to the consideration of alternative strategies that may help delay the onset and progression of AD. There is increasing recognition that certain dietary and nutrition factors may play important roles in protecting against select key AD pathologies. Consistent with this, select nutraceuticals and phytochemical compounds have demonstrated anti-amyloidogenic, antioxidative, anti-inflammatory, and neurotrophic properties and as such, could serve as lead candidates for further novel AD therapeutic developments. Here we summarize some of the more promising dietary phytochemicals, particularly polyphenols that have been shown to positively modulate some of the important AD pathogenesis aspects, such as reducing β-amyloid plaques and neurofibrillary tangles formation, AD-induced oxidative stress, neuroinflammation, and synapse loss. We also discuss the recent development of potential contribution of gut microbiome in dietary polyphenol function.

Randomised controlled trials for the prevention of cognitive decline or dementia: A systematic review

Dementia prevention research has progressed rapidly in recent years, with publication of several large lifestyle intervention trials, and renewed interest in pharmacological interventions, notably for individuals with Alzheimer's disease biomarkers, warranting an updated review of results and methodology. We identified 112 completed trials testing the efficacy of single-domain pharmacological (n = 33, 29%), nutritional (n = 27, 24%), physical activity (n = 18, 16%) and cognitive stimulation (n = 13, 12%), or multidomain (n = 22, 20%) interventions on incident dementia, or a relevant intermediate marker (e.g. cognitive function, biomarkers or dementia risk scores) in people without dementia. The earliest trials tested pharmacological interventions or nutritional supplements, but lifestyle interventions predominated in the last decade. In total, 21 (19%) trials demonstrated a clear beneficial effect on the pre-specified primary outcome (or all co-primary outcomes), but only two (10%) were large-scale (testing blood pressure lowering (Syst-Eur) or multidomain (FINGER) interventions on incident dementia and cognitive change in cognitive function, respectively). Of the 116 ongoing trials, 40% (n = 46) are testing multidomain interventions. Recent methodological shifts concern target populations, primary outcome measures, and intervention design, but study design remains constant (parallel group randomised controlled trial). Future trials may consider using adaptive trials or interventions, and more targeted approaches, since certain interventions may be more effective in certain subgroups of the population, and at specific times in the life-course. Efforts should also be made to increase the representativeness and diversity of prevention trial populations.

Mental Performance and Sport: Caffeine and Co-consumed Bioactive Ingredients

The plant defence compound caffeine is widely consumed as a performance enhancer in a sporting context, with potential benefits expected in both physiological and psychological terms. However, although caffeine modestly but consistently improves alertness and fatigue, its effects on mental performance are largely restricted to improved attention or concentration. It has no consistent effect within other cognitive domains that are important to sporting performance, including working memory, executive function and long-term memory. Although caffeine's central nervous system effects are often attributed to blockade of the receptors for the inhibitory neuromodulator adenosine, it also inhibits a number of enzymes involved both in neurotransmission and in cellular homeostasis and signal propagation. Furthermore, it modulates the pharmacokinetics of other endogenous and exogenous bioactive molecules, in part via interactions with shared cytochrome P450 enzymes. Caffeine therefore enjoys interactive relationships with a wide range of bioactive medicinal and dietary compounds, potentially broadening, increasing, decreasing, or modulating the time course of their functional effects, or vice versa. This narrative review explores the mechanisms of action and efficacy of caffeine and the potential for combinations of caffeine and other dietary compounds to exert psychological effects in excess of those expected following caffeine alone. The review focusses on, and indeed restricted its untargeted search to, the most commonly consumed sources of caffeine: products derived from caffeine-synthesising plants that give us tea (Camellia sinensis), coffee (Coffea genus), cocoa (Theabroma cacao) and guaraná (Paullinia cupana), plus multi-component energy drinks and shots. This literature suggests relevant benefits to mental performance that exceed those associated with caffeine for multi-ingredient energy drinks/shots and several low-caffeine extracts, including high-flavanol cocoa and guarana. However, there is a general lack of research conducted in such a way as to disentangle the relative contributions of the component parts of these products.

From Cocoa to Chocolate: Effect of Processing on Flavanols and Methylxanthines and Their Mechanisms of Action

Despite the health benefits associated with the ingestion of the bioactive compounds in cocoa, the high concentrations of polyphenols and methylxanthines in the raw cocoa beans negatively influence the taste, confer the astringency and bitterness, and affect the stability and digestibility of the cocoa products. It is, therefore, necessary to process cocoa beans to develop the characteristic color, taste, and flavor, and reduce the astringency and bitterness, which are desirable in cocoa products. Processing, however, affects the composition and quantities of the bioactive compounds, resulting in the modification of the health-promoting properties of cocoa beans and chocolate. In this advanced review, we sought to better understand the effect of cocoa's transformational process into chocolate on polyphenols and methylxanthine and the mechanism of action of the original flavanols and methylxanthines. More data on the cocoa processing effect on cocoa bioactives are still needed for better understanding the effect of each processing step on the final polyphenolic and methylxanthine composition of chocolate and other cocoa products. Regarding the mechanisms of action, theobromine acts through the modulation of the fatty acid metabolism, mitochondrial function, and energy metabolism pathways, while flavanols mainly act though the protein kinases and antioxidant pathways. Both flavanols and theobromine seem to be involved in the nitric oxide and neurotrophin regulation.

Fish oil and probiotics supplementation through milk chocolate improves spatial learning and memory in male Wistar rats

Background

Cognition and brain function is critical through childhood and should be improved with balanced diets. Incorporating bioactive ingredients such as omega-3 polyunsaturated fatty acids (ω3 PUFAs) and probiotics into food formulations could be used as an approach to improve cognitive function. This study evaluated the effects on cognitive capacity of complementing rodent diets with chocolate, by itself and in combination with ω3 PUFAs from fish oil and probiotics.

Methods

Spatial learning and memory in the rats were determined by the Barnes maze test in short- and long-term memory. Samples from the cecum were obtained to assess microbial counts (Lactobacillus, Bifidobacterium, Enterobacteriaceae, and total bacteria), and brains were recovered to analyze the neural morphology of the tissues. Also, glucose, brain weights, and epididymal tissue were analyzed.

Results

The combination of chocolate with fish oil and probiotics improved the memory of rats compared to the result of each bioactive compound when evaluated separately. Treatments did not affect sugar level, epididymal adipose tissue, or brain weight. On the other hand, consuming probiotics alone or in combination with chocolate decreased Enterobacteria counts, while Lactobacillus and Bifidobacteria counts were not affected. Neural morphological analysis showed that combining chocolate with probiotics and ω3 PUFAs increased the number of neurons in the hippocampal CA1 and CA3 regions.

Conclusion

Chocolate added with probiotics and ω3 PUFAs improved spatial memory and learning in the studied model.

Dietary Flavonoids and Human Cognition: A Meta-Analysis

Improving cognition is important in all age groups, from performance in school examinations to prevention of cognitive decline in later life. Dietary polyphenols, in particular flavonoids, have been examined for their benefits to cognitive outcomes. This meta-analysis evaluates the effects of dietary flavonoids on cognition across the lifespan. In January 2020 databases were searched for randomized controlled trials investigating flavonoid effects on human cognition. Eighty studies, comprising 5519 participants, were included in the final meta-analysis. The global analysis indicates dietary flavonoids induced significant benefit to cognitive performance (g = 0.148, p < 0.001), with subgroup analyses revealing that cocoa (g = 0.224, p = 0.036), ginkgo (g = 0.187, p ≤ 0.001), and berries (g = 0.149, p = 0.009) yielded the most notable improvements. Significant benefits were observed from chronic studies, in middle-aged and older adults, and with low and medium doses. The domains of long-term memory, processing speed, and mood showed sensitivity to flavonoid intervention. This meta-analysis provides evidence for the positive effects of flavonoids on cognition and highlights several moderating factors. Flavonoid-based dietary interventions therefore potentially offer a highly accessible, safe, and cost-effective treatment to help tackle the burden of cognitive decline.