Enhanced neural activation with blueberry supplementation in mild cognitive impairment

Hormetic Nutrition and Redox Regulation in Gut-Brain Axis Disorders

The antioxidant and anti-inflammatory effects of hormetic nutrition for enhancing stress resilience and overall human health have received much attention. Recently, the gut-brain axis has attracted prominent interest for preventing and therapeutically impacting neuropathologies and gastrointestinal diseases. Polyphenols and polyphenol-combined nanoparticles in synergy with probiotics have shown to improve gut bioavailability and blood-brain barrier (BBB) permeability, thus inhibiting the oxidative stress, metabolic dysfunction and inflammation linked to gut dysbiosis and ultimately the onset and progression of central nervous system (CNS) disorders. In accordance with hormesis, polyphenols display biphasic dose-response effects by activating at a low dose the Nrf2 pathway resulting in the upregulation of antioxidant vitagenes, as in the case of heme oxygenase-1 upregulated by hidrox® or curcumin and sirtuin-1 activated by resveratrol to inhibit reactive oxygen species (ROS) overproduction, microbiota dysfunction and neurotoxic damage. Importantly, modulation of the composition and function of the gut microbiota through polyphenols and/or probiotics enhances the abundance of beneficial bacteria and can prevent and treat Alzheimer's disease and other neurological disorders. Interestingly, dysregulation of the Nrf2 pathway in the gut and the brain can exacerbate selective susceptibility under neuroinflammatory conditions to CNS disorders due to the high vulnerability of vagal sensory neurons to oxidative stress. Herein, we aimed to discuss hormetic nutrients, including polyphenols and/or probiotics, targeting the Nrf2 pathway and vitagenes for the development of promising neuroprotective and therapeutic strategies to suppress oxidative stress, inflammation and microbiota deregulation, and consequently improve cognitive performance and brain health. In this review, we also explore interactions of the gut-brain axis based on sophisticated and cutting-edge technologies for novel anti-neuroinflammatory approaches and personalized nutritional therapies.

Chronic and postprandial effect of blueberries on cognitive function, alertness, and mood in participants with metabolic syndrome - results from a six-month, double-blind, randomized controlled trial

BACKGROUND

Anthocyanin and blueberry intakes positively associated with cognitive function in population-based studies and cognitive benefits in randomized controlled trials of adults with self-perceived or clinical cognitive dysfunction. To date, adults with metabolic syndrome (MetS) but without cognitive dysfunction are understudied.

OBJECTIVES

Cognitive function, mood, alertness, and sleep quality were assessed as secondary end points in MetS participants, postprandially (>24 h) and following 6-mo blueberry intake.

METHODS

A double-blind, randomized controlled trial was conducted, assessing the primary effect of consuming freeze-dried blueberry powder, compared against an isocaloric placebo, on cardiometabolic health >6 mo and a 24 h postprandial period (at baseline). In this secondary analysis of the main study, data from those completing mood, alertness, cognition, and sleep assessments are presented (i.e., n = 115 in the 6 mo study, n = 33 in the postprandial study), using the following: 1) Bond-Lader self-rated scores, 2) electronic cognitive battery (i.e., testing attention, working memory, episodic memory, speed of memory retrieval, executive function, and picture recognition), and 3) the Leeds Sleep Evaluation Questionnaire. Urinary and serum anthocyanin metabolites were quantified, and apolipoprotein E genotype status was determined.

RESULTS

Postprandial self-rated calmness significantly improved after 1 cup of blueberries (P = 0.01; q = 0.04; with an 11.6% improvement compared with baseline between 0 and 24 h for the 1 cup group), but all other mood, sleep, and cognitive function parameters were unaffected after postprandial and 6-mo blueberries. Across the ½ and 1 cup groups, microbial metabolites of anthocyanins and chlorogenic acid (i.e., hydroxycinnamic acids, benzoic acids, phenylalanine derivatives, and hippuric acids) and catechin were associated with favorable chronic and postprandial memory, attention, executive function, and calmness.

CONCLUSIONS

Although self-rated calmness improved postprandially, and significant cognition-metabolite associations were identified, our data did not support strong cognitive, mood, alertness, or sleep quality improvements in MetS participants after blueberry intervention. This trial was registered at clinicaltrials.gov as NCT02035592.

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.

Effect of Polyphenol Supplementation on Memory Functioning in Overweight and Obese Adults: A Systematic Review and Meta-Analysis

Negative health consequences of obesity include impaired neuronal functioning and cell death, thus bringing the risk of impaired cognitive functioning. Antioxidant properties of polyphenols offer a possible intervention for overweight people, but evidence for their effectiveness in supporting cognitive functioning is mixed. This review examined evidence from randomized controlled trials concerning the effect of polyphenols on tasks requiring either immediate or delayed retrieval of learned information, respectively, thus controlling for differences in cognitive processes and related neural substrates supporting respective task demands. Searches of the PubMed/Medline, PsycInfo, and Scopus databases identified 24 relevant primary studies with N = 2336 participants having a BMI ≥ 25.0 kg/m2. The participants' mean age for the 24 studies exceeded 60 years. Respective meta-analyses produced a significant summary effect for immediate retrieval but not for delayed retrieval. The present findings support a potential positive effect of chronic supplementation with polyphenols, most notably flavonoids, on immediate retrieval in participants aged over 60 years with obesity being a risk factor for cognitive impairment. We recommend further investigation of this potential positive effect in participants with such risk factors. Future research on all populations should report the phenolic content of the supplementation administered and be specific regarding the cognitive processes tested.

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.

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.

Synthetic and Natural Bioactive Molecules in Balancing the Crosstalk among Common Signaling Pathways in Alzheimer's Disease: Understanding the Neurotoxic Mechanisms for Therapeutic Intervention

The structure and function of the brain greatly rely on different signaling pathways. The wide variety of biological processes, including neurogenesis, axonal remodeling, the development and maintenance of pre- and postsynaptic terminals, and excitatory synaptic transmission, depends on combined actions of these molecular pathways. From that point of view, it is important to investigate signaling pathways and their crosstalk in order to better understand the formation of toxic proteins during neurodegeneration. With recent discoveries, it is established that the modulation of several pathological events in Alzheimer's disease (AD) due to the mammalian target of rapamycin (mTOR), Wnt signaling, 5'-adenosine monophosphate activated protein kinase (AMPK), peroxisome proliferator-activated receptor gamma coactivator 1α (PGC-1α), and sirtuin 1 (Sirt1, silent mating-type information regulator 2 homologue 1) are central to the key findings. These include decreased amyloid formation and inflammation, mitochondrial dynamics control, and enhanced neural stability. This review intends to emphasize the importance of these signaling pathways, which collectively determine the fate of neurons in AD in several ways. This review will also focus on the role of novel synthetic and natural bioactive molecules in balancing the intricate crosstalk among different pathways in order to prolong the longevity of AD patients.

Anthocyanins: Molecular Aspects on Their Neuroprotective Activity

Anthocyanins are a type of flavonoids that give plants and fruits their vibrant colors. They are known for their potent antioxidant properties and have been linked to various health benefits. Upon consumption, anthocyanins are quickly absorbed and can penetrate the blood-brain barrier (BBB). Research based on population studies suggests that including anthocyanin-rich sources in the diet lower the risk of neurodegenerative diseases. Anthocyanins exhibit neuroprotective effects that could potentially alleviate symptoms associated with such diseases. In this review, we compiled and discussed a large body of evidence supporting the neuroprotective role of anthocyanins. Our examination encompasses human studies, animal models, and cell cultures. We delve into the connection between anthocyanin bioactivities and the mechanisms underlying neurodegeneration. Our findings highlight how anthocyanins' antioxidant, anti-inflammatory, and anti-apoptotic properties contribute to their neuroprotective effects. These effects are particularly relevant to key signaling pathways implicated in the development of Alzheimer's and Parkinson's diseases. In conclusion, the outcome of this review suggests that integrating anthocyanin-rich foods into human diets could potentially serve as a therapeutic approach for neurological conditions, and we identify promising avenues for further exploration in this area.

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.

Impact of Polyphenols on Inflammatory and Oxidative Stress Factors in Diabetes Mellitus: Nutritional Antioxidants and Their Application in Improving Antidiabetic Therapy

Diabetes mellitus is a chronic metabolic disorder characterized by hyperglycaemia and oxidative stress. Oxidative stress plays a crucial role in the development and progression of diabetes and its complications. Nutritional antioxidants derived from dietary sources have gained significant attention due to their potential to improve antidiabetic therapy. This review will delve into the world of polyphenols, investigating their origins in plants, metabolism in the human body, and relevance to the antioxidant mechanism in the context of improving antidiabetic therapy by attenuating oxidative stress, improving insulin sensitivity, and preserving β-cell function. The potential mechanisms of, clinical evidence for, and future perspectives on nutritional antioxidants as adjuvant therapy in diabetes management are discussed.

Urolithins: A Prospective Alternative against Brain Aging

The impact of host-microbiome interactions on cognitive health and disease has received increasing attention. Microbial-derived metabolites produced in the gut are one of crucial mechanisms of the gut-brain axis interaction, showing attractive perspectives. Urolithins (Uros) are gut microbial-derived metabolites of ellagitannins and ellagic acid, whose biotransformation varies considerably between individuals and decreases greatly with age. Recently, accumulating evidence has suggested that Uros may have specific advantages in preventing brain aging including favorable blood-brain barrier permeability, selective brain distribution, and increasingly supporting data from preclinical and clinical studies. However, the usability of Uros in diagnosis, prevention, and treatment of neurodegenerative diseases remains elusive. In this review, we aim to present the comprehensive achievements of Uros in age-related brain dysfunctions and neurodegenerative diseases and discuss their prospects and knowledge gaps as functional food, drugs, or biomarkers against brain aging.

Perspective: Challenges and Future Directions in Clinical Research with Nuts and Berries

Consumption of nuts and berries are considered part of a healthy eating pattern. Nuts and berries contain a complex nutrient profile consisting of essential vitamins and minerals, fiber, polyunsaturated fatty acids, and phenolics in quantities that improve physiological outcomes. The spectrum of health outcomes that may be impacted by the consumptions of nuts and berries includes cardiovascular, gut microbiome, and cognitive, among others. Recently, new insights regarding the bioactive compounds found in both nuts and berries have reinforced their role for use in precision nutrition efforts. However, challenges exist that can affect the generalizability of outcomes from clinical studies, including inconsistency in study designs, homogeneity of test populations, variability in test products and control foods, and assessing realistic portion sizes. Future research centered on precision nutrition and multi-omics technologies will yield new insights. These and other topics such as funding streams and perceived risk-of-bias were explored at an international nutrition conference focused on the role of nuts and berries in clinical nutrition. Successes, challenges, and future directions with these foods are presented here.

Blueberry extracts antagonize Aβ25-35 neurotoxicity and exert a neuroprotective effect through MEK-ERK-BDNF/UCH-L1 signaling pathway in rat and mouse hippocampus

BACKGROUND

The neuroprotective potential of blueberry (BB) extracts against Alzheimer's disease (AD) has been previously hinted at, while its exact mechanism has remained largely enigmatic.

OBJECTIVE

Our study endeavored to unravel the impacts and mechanisms by which BB extracts ameliorated the learning and memory prowess of AD-afflicted mice, with a specific focus on the MEK-ERK pathway.

METHODS

We employed 3-month-old APP/PS1 transgenic mice and stratified them into three distinct groups: AD+BB, AD, and control (CT). The Morris Water Maze Test (MWMT) was then administered to gauge their learning and memory faculties. In vitro experiments were executed on Aβ25-35-afflicted rat hippocampal neurons, which were subsequently treated with varying concentrations of BB extracts. We then assessed the expression levels of genes and proteins integral to the MEK-ERKBDNF/UCH-L1 pathway.

RESULTS

The data showed that the AD mice demonstrated compromised learning and memory faculties in MWMT. However, the AD+BB cohort showcased marked improvements in performance. Furthermore, in the AD subset, significant elevations in the expressions of MEK2 and ERK1/2 were observed, both at the mRNA and protein levels. Conversely, UCH-L1 mRNA expressions exhibited a decline, while BDNF expressions surged significantly. However, post BB extract treatment, the expressions of MEK2 and ERK1/2 were subdued, with UCH-L1 and BDNF mRNA expressions reverting to control levels.

CONCLUSIONS

Our findings propounded that BB extracts could offer therapeutic promise for AD by bolstering learning and memory capacities. The unwarranted activation of the MEK-ERK pathway, coupled with the aberrant expressions of BDNF and UCH-L1, might underpin AD's pathogenesis.

Blueberry Supplementation Effects on Neuronal and Pathological Biomarkers in Subjects at Risk for Alzheimer's Disease: A Pilot Study

Background

There is a need to develop non-invasive practical lifestyle interventions for preventing Alzheimer's disease (AD) in people at risk, such as those with mild cognitive impairment (MCI). Blueberry consumption has been associated with reduced risk of dementia in some epidemiologic studies and with improvements in cognition in healthy aging adults. Blood-based biomarkers have emerged at the forefront of AD therapeutics research spurred by the development of reliable ultra-sensitive "single-molecule array" assays with 100-1000-fold greater sensitivity over traditional platforms.

Objective

The purpose of this study was to examine the effect of blueberry supplementation in MCI on six blood biomarkers: amyloid-beta 40 (Aβ40), amyloid-beta 42 (Aβ42), phosphorylated Tau181 (ptau181), neurofilament light (NfL), Glial Fibrillary acidic protein (GFAP), and Brain-Derived Neurotrophic Factor (BDNF).

Methods

This was a 12-week, open-label, pilot trial of 10 participants with MCI (mean age 80.2 years + 5.16). Subjects consumed 36 grams per day of lyophilized blueberry powder in a split dose consumed with breakfast and dinner. Baseline and endpoint venous blood was analyzed using an ultrasensitive SIMOA assay. Our aim was to test if blueberry supplementation would particularly impact p-tau181, NfL, and GFAP elevations associated with the neurodegenerative process.

Results

There were no statistically significant (p < 0.05) changes from baseline to endpoint for any of the biomarker values or in the ratios of Aβ42 / Aβ40 and ptau181/ Aβ42. Adverse effects were mild and transient; supplementation was relatively well tolerated with all subjects completing the study.

Conclusion

To our knowledge, this is the first study to prospectively examine the effects of blueberry supplementation on a panel of blood biomarkers reflecting the neurodegenerative process. Our findings raise two possibilities - a potential stabilization of the neurodegenerative process or a lack of a direct and acute effect on beta-amyloid/tau/glial markers. A larger controlled study is warranted.

Targeting gut-brain axis by dietary flavonoids ameliorate aging-related cognition decline: Evidences and mechanisms

Aging-related cognitive impairment, mainly Alzheimer's disease (AD), has been widely studied. However, effective prevention and treatment methods are still lacking. In recent years, researchers have observed beneficial effects of plant-based supplements, such as flavonoids, on cognitive protection. This provides a new clue for the prevention of cognitive dysfunction. Studies have shown that dietary flavonoids have neuroprotective effects, but the mechanism is not clear. In this review, we systematically reviewed the research progress on the effects of dietary flavonoids on gut microbes and their metabolites, and concluded that flavonoids could improve cognitive function through the gut-brain axis. Flavonoids can be absorbed through the intestine, cross the blood-brain barrier, and enter the brain tissue. Flavonoids can inhibit the expression and secretion of inflammatory factors in brain tissue, reduce the damage caused by oxidative stress, clear neural damage proteins and inhibit neuronal apoptosis, thereby ameliorating age-related cognitive disorders. Future work will continue to explore the gut-brain axis and target genes regulated by flavonoids. In addition, clinical research and its mechanisms need to be further explored to provide solutions or advise for patients with cognitive impairment.

Polyphenol supplementation and executive functioning in overweight and obese adults at risk of cognitive impairment: A systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Increasing evidence indicates a link between obesity and cognitive impairment. Furthermore, there is limited literature regarding the effect of polyphenols, a plant derived compounds, on executive functioning in an overweight/obese population at-risk of cognitive impairment. The aim of the present systematic review and meta-analysis of randomized controlled trials is to examine the effect of polyphenol supplementation on executive functions in overweight and/or obese populations at risk of cognitive impairment.

METHODS

A comprehensive literature search was conducted from inception to March 2023 using four electronic databases: PubMed/Medline, PsycInfo, Scopus and Cochrane trials library. Published primary research studies in English that compared the effect of polyphenols with placebo on executive function in overweight/obese adults were considered eligible for the meta-analysis. Jadad scale was used for the methodological quality rating of the included studies. Hedges g with 95% confidence intervals (CI) for endpoints were calculated using random effect model where applicable. Rosenthal's Fail-safe N, funnel plots, the Begg and Mazumdar's rank correlation test (Kendall's S statistic P-Q), Egger's linear regression test, and Duval and Tweedie's trim-and-fill test were identified for potential use as appropriate, to examine publication bias. Sensitivity analysis was conducted to examine the robustness of the results.

RESULTS AND CONCLUSION

A total of 23 RCT studies involving N = 1,976 participants were included in the review. The results of the meta-analysis revealed a non-significant effect for polyphenol supplementation on executive function (g = 0.076, CI = -0.018 to 0.170). Observations from primary studies within the meta-analysis showed a potential positive effect of polyphenol supplementation in a younger population at-risk of cognitive impairment and it is recommended to investigate this further in future studies. Moreover, the variability of the tasks used to examine executive functions as well as the adequate reporting of supplement's phenolic composition is a limitation that future work should also consider.

Current trends in natural products for the treatment and management of dementia: Computational to clinical studies

The number of preclinical and clinical studies evaluating natural products-based management of dementia has gradually increased, with an exponential rise in 2020 and 2021. Keeping this in mind, we examined current trends from 2016 to 2021 in order to assess the growth potential of natural products in the treatment of dementia. Publicly available literature was collected from various databases like PubMed and Google Scholar. Oxidative stress-related targets, NF-κB pathway, anti-tau aggregation, anti-AChE, and A-β aggregation were found to be common targets and pathways. A retrospective analysis of 33 antidementia natural compounds identified 125 sustainable resources distributed among 65 families, 39 orders, and 7 classes. We found that families such as Berberidaceae, Zingiberaceae, and Fabaceae, as well as orders such as Lamiales, Sapindales, and Myrtales, appear to be important and should be researched further for antidementia compounds. Moreover, some natural products, such as quercetin, curcumin, icariside II, berberine, and resveratrol, have a wide range of applications. Clinical studies and patents support the importance of dietary supplements and natural products, which we will also discuss. Finally, we conclude with the broad scope, future challenges, and opportunities for field researchers.

THE EFFECTS OF CURCUMIN AND BLUEBERRY ON AXONAL REGENERATION AFTER PERIPHERAL NERVE INJURY

The purpose of this study was to analyze the axonal regeneration and therapeutic effects of curcumin and blueberry administration following peripheral nerve injury using stereological, electron microscopic and electrophysiological methods. Animals in were assigned into one of four groups - control (Cont), injury (Inj), injury+curcumin (Cur) and injury+blueberry (Blue). Following the induction of sciatic nerve crush injury (75 Newtons for 5sec) in the Inj, Cur, and Blue groups, the rats in the Cur group received intraperitoneal injection of 30mg/kg curcumin (Sigma C1386) and the rats in the Blue group received 4g/kg blueberry by gavage over a four-week period. The rats in the Cont and Inj groups were not exposed to any substance. All animals were given standard chow. Sciatic functional index analyses were performed on the 14^th and 28^th days after injury, and electromyography (EMG) results were recorded. Stereological analysis of the nerve was performed under light microscopy. Light and electron microscopies were used for the histopathological evaluation of the sciatic nerve. Analysis of myelinated axon numbers revealed no significant differences between the Inj group and the Cur and Blue groups. However, a significant difference was observed between the Blue and Inj groups in terms of axonal areas. EMG test results differed between the Blue and the Inj groups (p<0.05), but no significant difference was observed between the Inj and Cur groups. Electron microscopic analysis revealed protective effects of curcumin and blueberry treatment after injury. The use of the curcumin and blueberry may represent a supportive approach to the protection of nerve fibers after peripheral nerve crush injury.

Wild Blueberry (Poly)phenols can Improve Vascular Function And Cognitive Performance In Healthy Older Males And Females: A Double-Blind Randomized Controlled Trial

BACKGROUND

Evidence suggests that intake of blueberry (poly)phenols is associated with improvements in vascular function and cognitive performance. Whether these cognitive effects are linked to increases in cerebral and vascular blood flow or changes in the gut microbiota is currently unknown.

METHODS

A double-blind, parallel randomized controlled trial was conducted in 61 healthy older individuals aged 65-80 y. Participants received either 26g of freeze-dried wild blueberry (WBB) powder (302 mg anthocyanins) or a matched placebo (0 mg anthocyanins). Endothelial function measured by flow-mediated dilation (FMD), cognitive function, arterial stiffness, blood pressure (BP), cerebral blood flow (CBF), gut microbiome and blood parameters were measured at baseline and 12 weeks following daily consumption. Plasma and urinary (poly)phenol metabolites were analyzed using micro-elution solid phase-extraction coupled with LC-MS.

RESULTS

A significant increase in FMD and reduction in 24 h ambulatory systolic BP were found in the WBB group compared to placebo (0.86%; 95% CI 0.56, 1.17, p<0.001; -3.59 mmHg; 95% CI -6.95, -0.23, p=0.037; respectively). Enhanced immediate recall on the auditory verbal learning task, alongside better accuracy on a task-switch task were also found following WBB treatment compared to placebo (p<0.05). Total 24 h urinary (poly)phenol excretion increased significantly in the WBB group compared to placebo. No changes in CBF or gut microbiota composition were found.

CONCLUSIONS

Daily intake of WBB powder, equivalent to 178 g fresh weight, improves vascular and cognitive function, and decreases 24h ambulatory systolic BP in healthy older individuals. This suggests that WBB (poly)phenols may reduce future cardiovascular disease (CVD) disease risk in an older population, and may improve episodic memory processes and executive functioning in older adults at risk of cognitive decline. CLINICAL TRIAL REGISTRATION NUMBER IN CLINICALTRIALS.GOV: NCT04084457.

"I Always Buy the Purple Ones … If I See Them": Socioecological Factors Influencing Anthocyanin-Rich Food Consumption for Cognitive Health in Older Adults

Despite the positive relationship between anthocyanin-rich foods and cognitive health, a dietary deficit exists in older adults. Effective interventions require an understanding of people's dietary behaviors situated in social and cultural contexts. Therefore, the aim of this study was to explore older adults' perceptions about increasing their consumption of anthocyanin-rich foods for cognitive health. Following an educational session and the provision of a recipe and information book, an online survey and focus groups with Australian adults aged 65 years or older (n = 20) explored the barriers and enablers towards eating more anthocyanin-rich foods and potential strategies to achieve dietary change. An iterative, qualitative analysis identified the themes and classified the barriers, enablers and strategies onto the Social-Ecological model levels of influence (individual, interpersonal, community, society). Enabling factors included a desire to eat healthily, taste preference and familiarity of anthocyanin-rich foods (individual), social support (community), and the availability of some anthocyanin-rich foods (society). The barriers included budget, dietary preferences and motivation (individual), household influences (interpersonal), limited availability and access to some anthocyanin-rich foods (community) and the cost and the seasonal variability (society). The strategies included increasing individual-level knowledge, skills, and confidence in utilizing anthocyanin-rich foods, educational initiatives about the potential cognitive benefits, and advocating to increase access to anthocyanin-rich foods in the food supply. This study provides for the first time, insight into the various levels of influence impacting older adults' ability to consume an anthocyanin-rich diet for cognitive health. Future interventions should be tailored to reflect the barriers and enablers and to provide targeted education about anthocyanin-rich foods.

Effects of anthocyanin-rich supplementation on cognition of the cognitively healthy middle-aged and older adults: a systematic review and meta-analysis of randomized controlled trials

CONTEXT

The prevalence of age-related cognitive decline has been on the rise as the global population age, putting the independence and quality of life of elderly at risk. Anthocyanin, as a subclass of dietary flavonoids, may have a beneficial impact on cognitive outcomes.

OBJECTIVES

To examine the effects of dietary anthocyanin supplementation on cognition of the cognitively healthy middle-aged and older adults.

DATA SOURCES

PubMed, ScienceDirect, CINAHL, EMBASE, ProQuest and Cochrane databases were searched.

DATA EXTRACTION AND ANALYSIS

Thirteen studies were included in this meta-analysis. Anthocyanin-rich supplementation was found to significantly improve the processing speed of the older adults (95%CI 0.08, 0.44; P = 0.004). No significant differences were observed between intervention and control groups on memory, attention, executive function and psychomotor performance. Current neuroimaging studies have found promising effects of anthocyanin supplementation on brain activation and cerebral perfusion.

CONCLUSION

Anthocyanin-rich supplementation may preserve cognitive processing speed and neuro-activities in older adults, which improves their daily functioning and quality of life. This review provides useful insights to guide direction and methodological designs for future studies to explore the underlying mechanisms of anthocyanins.

SYSTEMATIC REVIEW AND META-ANALYSIS REGISTRATION

PROSPERO registration No. CRD42021228007.

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.

A Randomised Placebo-Controlled Study of Purified Anthocyanins on Cognition in Individuals at Increased Risk for Dementia

IMPORTANCE

Identifying nutritional compounds which can reduce cognitive decline in older people is a hugely important topic.

OBJECTIVE

To study the safety and effect of anthocyanins in maintaining cognitive functioning in people at increased risk for dementia.

DESIGN, SETTING, AND PARTICIPANTS

Participants (206 individuals, aged 60-80 years) diagnosed with either mild cognitive impairment (MCI) or two or more cardiometabolic disorders (i.e., diabetes, hypertension, obesity) were enrolled at three different centres in Norway.

INTERVENTION

Participants were randomly assigned to four capsules with a total of 320 mg/d of naturally purified anthocyanins or placebo 1:1 for 24 weeks.

MAIN OUTCOMES AND MEASURES

The primary outcome was the Quality of Episodic Memory composite measure (0-100) from an online cognitive test battery CogTrack, which was administered at baseline and monthly for the next 24 weeks. Secondary outcomes included other cognitive scores from the CogTrack battery. We applied mixed effects models with a baseline test score, group, time and their interaction as fixed effects, as well as other predefined baseline covariates. The primary comparison was the group difference at week 24 based on a modified intention-to-treat principle.

RESULTS

The primary analysis did not show a significant group difference at 24 weeks (78.2 versus 76.8; adjusted mean difference 1.4 (95% confidence interval -0.9-3.7); effect size 0.15; p = 0.23). However, there was a significant difference in slopes during weeks 8-24 (p = 0.007); the anthocyanin group improved while the placebo group worsened. No differences were found for the secondary cognitive outcomes. Anthocyanin capsules were well-tolerated and safe to use.

CONCLUSION

Anthocyanin supplementation for 24 weeks was safe and well tolerated in people with MCI or cardiometabolic disorders. We found no significant group difference in episodic memory at the end of the study but statistically significant differences in slopes. Further studies are warranted to explore whether anthocyanins supplementation can reduce cognitive decline in people at increased risk of dementia.

TRIAL REGISTRATION

ClinicalTrials.gov, (Identifier NCT03419039). http://www.

CLINICALTRIALS

gov/, NCT03419039.

Eat for better cognition in older adults at risk for Alzheimer's disease

Alzheimer's disease is a worldwide public health problem. However, the treatment method and treatment effects are limited. The stages of preclinical Alzheimer's disease are thought to be a better intervention period. Thus, in this review, food is given focus and the intervention stage put forward. We summarized the role of diet, nutrient supplementation, and microbioecologics in cognitive decline and found that interventions such as modified Mediterranean-ketogenic diet, nuts, vitamin B, and Bifidobacterium breve A1 are beneficial to cognition protection. Eating, rather than just taking medicine, is suggested to be an effective treatment method for older adults at risk for Alzheimer's disease.

Complementary and Alternative Medicine Approaches in Alzheimer Disease and Other Neurocognitive Disorders

As our population ages, there is interest in delaying or intervening in cognitive decline. While newer agents are under development, agents in mainstream use do not impact the course of diseases that cause cognitive decline. This increases interest in alternative strategies. Even as we welcome possible new disease-modifying agents, they are likely to remain costly. Herein, we review the evidence behind other complementary and alternative strategies for cognitive enhancement and prevention of cognitive decline.

An integrative approach to dementia care

As the aging population continues to increase, Alzheimer's disease and related dementias are becoming a global health crisis. The burdens experienced by the person living with dementia, their caregivers, healthcare, and society persist unabated. Persons with dementia represent an important population in need of a tenable care plan. Caregivers need the tools with which to properly care for these persons and to mitigate their own stress response. A viable healthcare model utilizing integrated approaches to care for persons with dementia is in overwhelming demand. While much research is focused on a cure, it is equally important to address the difficulties faced by those currently affected. One approach is to incorporate interventions to increase quality of life within the caregiver-patient dyad via a comprehensive integrative model. Improving daily life of the persons with dementia, along with their caregivers and loved ones may aid in attenuating the pervasive psychological and physical impacts of this disease. A focus on interventions that provide neural and physical stimulation may facilitate quality of life in this regard. The subjective experience of this disease is challenging to capture. The relationship between neurocognitive stimulation and quality of life is at least, in part, therefore still uncertain. This narrative review aims to explore the efficacy and evidence-base of an integrative approach to dementia care in facilitating optimal cognition and quality of life outcomes. These approaches will be reviewed alongside person-centered care that is fundamental to integrative medicine, including exercise; music; art and creativity; nutrition; psychosocial engagement; memory training; and acupuncture.

Effects of chronic consumption of specific fruit (berries, cherries and citrus) on cognitive health: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVES

The cognitive-protective effects related to the consumption of a variety of fruits are supported by several intervention studies. This systematic review and meta-analysis compared the magnitude of effects following chronic (≥1 week) consumption of frozen, freeze-dried powder including extracts and juices of fruits, covering berries, cherries and citrus, on cognition and mood in adults.

METHODS

PubMed, Web of Science, Scopus, and psycARTICLES were searched from inception until February, 2021. Inclusion criteria were randomised controlled trials assessing memory, executive function, psychomotor speed, mood and mini mental state examination in adult participants ≥18 years of age. Cognition was tested by global or domain specific tasks.

RESULTS

Out of 13,861 articles identified, 16 papers were included; 11 studies provided suitable data for meta-analysis. Fourteen studies reported improvement or trend for improvement in cognition, five studies assessed mood and one study supplementing grape juice found trend for mood improvement. From the meta-analysis, cherry juice supplementation was suggested to improve psychomotor speed by -0.37 of standardised mean difference (95% CI [-0.74, 0.01]) in reaction time (P = 0.05).

CONCLUSIONS

The meta-analysis did not sufficiently support a role for fruits or fruit forms to improve cognition and mood.

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.

Neuroinflammation: The Role of Anthocyanins as Neuroprotectants

Neuroinflammation is a trigger for several neurodegenerative and neuropsychiatric disorders. Exposure to noxious external stimuli induces homeostatic disturbances resulting in morphological changes in microglia, their activation, and elaboration of pro-inflammatory mediators. This leads to neuroinflammation with the progressive loss of neurons. Nutraceuticals such as anthocyanins are a class of brightly colored bioactive compounds present in fruits and vegetables with purported health benefits. They interfere with the activation of several signaling cascades that have a prominent role in preventing neuroinflammation. More importantly, anthocyanins can cross the blood-brain barrier and are safe. Hence, the current review focuses on the bioavailability of anthocyanins, clinical and in vitro evidence on their role in impeding the activation of transcription factors, modulating the immune milieu within the central nervous system, preventing the activation of microglia, and averting neuroinflammation.

Fruit and Vegetable Consumption and Cognitive Disorders in Older Adults: A Meta-Analysis of Observational Studies

Objectives

The aim of this meta-analysis was to assess the quantitative associations between fruit and vegetable intake and cognitive disorders in older adults.

Design

A meta-analysis.

Setting and Participants

We used the PubMed, Web of Science and Scopus databases for a literature search to 12 April 2022. We preliminarily retrieved 11,759 studies, 16 of which met the inclusion criteria including six cross-sectional studies, nine cohort studies and one case-control study, incorporating 64,348 participants and 9,879 cases.

Methods

Using the three databases, we identified observational studies exploring the association. The pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using a random effects model.

Results

Sixteen studies were included in the meta-analysis, and the results showed that increased fruit and vegetable consumption in older adults was associated with a decline in the prevalence of cognitive disorders (OR: 0.79, 95% CI: 0.76–0.83). Moreover, intake of fruits (OR: 0.83, 95% CI: 0.77–0.89) and vegetables (OR: 0.75, 95% CI: 0.70–0.80) alone were both associated with a lower prevalence of cognitive disorders. Subgroup analyses indicated that the intake of fruits and vegetables was associated with the prevalence of cognitive impairment (OR: 0.72, 95% CI: 0.76–0.80) and dementia (OR: 0.84, 95% CI: 0.78–0.91) but not Alzheimer’s disease (OR: 0.88, 95% CI: 0.76–1.01).

Conclusion and Implications

Our meta-analysis provides evidence that the intake of fruits and vegetables is inversely proportional and linearly associated with the prevalence of cognitive disorders in older adults. Future research is required to further investigate the preventive effects of the frequency, quantity, and duration of eating vegetables and fruits on cognitive disorders in older adults.

Anthocyanins in Chronic Diseases: The Power of Purple

Anthocyanins are mainly purple-coloured phenolic compounds of plant origin that as secondary metabolites are important in plant survival. Understanding their health benefits in humans requires sourcing these unstable compounds in sufficient quantities at a reasonable cost, which has led to improved methods of extraction. Dark-coloured fruits, cereals and vegetables are current sources of these compounds. The range of potential sustainable sources is much larger and includes non-commercialised native plants from around the world and agri-waste containing anthocyanins. In the last 5 years, there have been significant advances in developing the therapeutic potential of anthocyanins in chronic human diseases. Anthocyanins exert their beneficial effects through improvements in gut microbiota, oxidative stress and inflammation, and modulation of neuropeptides such as insulin-like growth factor-1. Their health benefits in humans include reduced cognitive decline; protection of organs such as the liver, as well as the cardiovascular system, gastrointestinal tract and kidneys; improvements in bone health and obesity; and regulation of glucose and lipid metabolism. This review summarises some of the sources of anthocyanins and their mechanisms and benefits in the treatment of chronic human diseases.

Chronic Consumption of Cranberries (Vaccinium macrocarpon) for 12 Weeks Improves Episodic Memory and Regional Brain Perfusion in Healthy Older Adults: A Randomised, Placebo-Controlled, Parallel-Groups Feasibility Study

Background

Ageing is highly associated with cognitive decline and modifiable risk factors such as diet are believed to protect against this process. Specific dietary components and in particular, (poly)phenol-rich fruits such as berries have been increasingly recognised for their protection against age-related neurodegeneration. However, the impact of cranberries on cognitive function and neural functioning in older adults remains unclear.

Design

A 12-week parallel randomised placebo-controlled trial of freeze-dried cranberry powder was conducted in 60 older adults aged between 50 and 80 years. Cognitive assessment, including memory and executive function, neuroimaging and blood sample collection were conducted before and after the intervention to assess the impact of daily cranberry consumption on cognition, brain function and biomarkers of neuronal signalling.

Results

Cranberry supplementation for 12 weeks was associated with improvements in visual episodic memory in aged participants when compared to placebo. Mechanisms of action may include increased regional perfusion in the right entorhinal cortex, the accumbens area and the caudate in the cranberry group. Significant decrease in low-density lipoprotein (LDL) cholesterol during the course of the intervention was also observed. No significant differences were, however, detected for BDNF levels between groups.

Conclusions

The results of this study indicate that daily cranberry supplementation (equivalent to 1 small cup of cranberries) over a 12-week period improves episodic memory performance and neural functioning, providing a basis for future investigations to determine efficacy in the context of neurological disease. This trial was registered at clinicaltrials.gov as NCT03679533 and at ISRCTN as ISRCTN76069316.

An Activation Likelihood Estimation Meta-Analysis of Specific Functional Alterations in Dorsal Attention Network in Mild Cognitive Impairment

Background

Mild cognitive impairment (MCI) is known as the prodromal stage of the Alzheimer’s disease (AD) spectrum. The recent studies have advised that functional alterations in the dorsal attention network (DAN) could be used as a sensitive marker to forecast the progression from MCI to AD. Therefore, our aim was to investigate specific functional alterations in the DAN in MCI.

Methods

We systematically searched PubMed, EMBASE, and Web of Science and chose relevant articles based on the three functional indicators, the amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), and functional connectivity (FC) in the DAN in MCI. Based on the activation likelihood estimation, we accomplished the aggregation of specific coordinates and the analysis of functional alterations.

Results

A total of 38 studies were involved in our meta-analysis. By summing up included articles, we acquired specific brain region alterations in the DAN mainly in the superior temporal gyrus (STG), middle temporal gyrus (MTG), superior frontal gyrus (SFG), middle frontal gyrus (MFG), inferior frontal gyrus (IFG), precentral gyrus (preCG), inferior parietal lobule (IPL), superior parietal lobule (SPL). At the same time, the key area that shows anti-interaction with default mode network included the IPL in the DAN. The one showing interactions with executive control network was mainly in the MFG. Finally, the frontoparietal network showed a close connection with DAN especially in the IPL and IFG.

Conclusion

This study demonstrated abnormal functional markers in the DAN and its interactions with other networks in MCI group, respectively. It provided the foundation for future targeted interventions in preventing the progression of AD.

Systematic Review Registration

[https://www.crd.york.ac.uk/PROSPERO/], identifier [CRD42021287958].

Probiotics and plant extracts: a promising synergy and delivery systems

There is a current interest in healthy diets and supplements, indicating the relevance of novel delivery systems for plant extracts rich in bioactive compounds and probiotics. This simultaneous delivery system can be prospective for health. In this sense, investigating foods rich in bioactive compounds or supplemented by them for incorporating probiotics and some approaches to improve probiotic survivability, such as the choice of resistant probiotic strains or microencapsulation, is valuable. This review addresses a brief discussion about the role of phenolic compounds, chlorophyll and carotenoids from plants and probiotics in gut health, indicating the benefits of this association. Also, an overview of delivery systems used in recent studies is shown, considering their advantages for incorporation in food matrices. Delivery systems containing compounds recovered from plants can reduce probiotic oxidative stress, improving survivability. However, investigating the beneficial concentration of some bioactive compounds from plant extracts is relevant due to their antimicrobial potential. In addition, further clinical trials and toxicological studies of plant extracts are pertinent to ensure safety. Thus, the recovery of extracts from plants emerges as an alternative to providing multiple compounds with antioxidant potential, increasing the preservation of probiotics and allowing the fortification or enrichment of food matrices.

Blueberry Supplementation in Midlife for Dementia Risk Reduction

Late-life dementia typically develops over a period of many years beginning in midlife. Prevalence of metabolic disturbance also accelerates in middle age and is a prominent risk factor for dementia. Preliminary studies indicate that blueberry supplementation can improve cognitive performance and influence metabolism and brain function and therefore may have a role in early intervention to prevent neurodegeneration. In a randomized controlled trial, we investigated the effects of daily blueberry supplementation in a middle-aged sample of insulin-resistant participants with elevated risk for future dementia. We enrolled overweight men and women, aged 50 to 65 years, with subjective cognitive decline (SCD) and performed pre- and post-intervention assessments of cognition and metabolism and exploratory measures of peripheral mitochondrial function. We observed improved performances for the blueberry group on measures of lexical access, p = 0.003, and memory interference, p = 0.04, and blueberry-treated participants reported reduced memory encoding difficulty in daily life activities, p = 0.03. The blueberry-treated group also exhibited correction of peripheral hyperinsulinemia, p = 0.04, and a modest trend for increased mitochondrial uncoupling, p = 0.11. The cognitive findings indicated improved executive ability in this middle-aged sample. In addition, the changes in metabolic and bioenergetic measures imply potential mechanistic factors associated with anthocyanin and proanthocyanidin actions. The demonstration of these benefits in middle-aged individuals with insulin resistance and SCD suggests that ongoing blueberry supplementation may contribute to protection against cognitive decline when implemented early in at-risk individuals.

Cyanidin-3-O-glucoside, cyanidin, and oxidation products of cyanidin protect neuronal function through alleviating inflammation and oxidative damage

Neurotoxicity seriously affects the normal function of the nervous system. Cyanidin-3-O-glucoside (C3G) is the most abundant anthocyanin widely distributed in plants. Using β-amyloid (Aβ) transgenic Caenorhabditis elegans and cell models, the neuroprotective effect of C3G was examined. The results showed that C3G remarkably suppressed Aβ aggregation, enhanced antioxidant capacity, improved the sensitive capacity towards chemical compounds, and boosted the memory ability of C. elegans. There was no significant difference between preventive and long-term treatment groups at the same dosage of C3G. Given the rapid metabolism and oxidation of C3G in vivo, the antioxidative and anti-inflammatory activities of C3G, the metabolite cyanidin (Cy), oxidation products of Cy (OP), as well as protocatechuic acid (PCA) at the corresponding level in OP were compared by using lipopolysaccharide (LPS)-stimulated BV2 microglia cell model. The results indicated that C3G, Cy, and OP could prevent BV2 cells against LPS-induced inflammation and oxidative damage. There was no significant difference on antioxidative and anti-inflammatory activities among C3G, Cy, and OP at the same level. Notably, PCA at the corresponding concentration in OP exhibited limited antioxidative and anti-inflammatory activities. The results suggested that C3G could exert neuroprotective function through the metabolite Cy and its oxidation products by inhibiting inflammation and oxidative damage, and PCA was not the primary bioactive species in OP. PRACTICAL APPLICATION: This study confirmed the neuroprotection of cyanidin-3-O-glucoside (C3G) in transgenic Caenorhabditis elegans. C3G, its metabolite cyanidin (Cy), and oxidation products of Cy (OP) alleviated both neuroinflammation and oxidative damage. It highlighted that C3G-rich foods could exert neuroprotective potential through their oxidation products, the constitution, and existence of OP in vivo need further study.

Food as medicine? Exploring the impact of providing healthy foods on adherence and clinical and economic outcomes

Background

Methods

Results

Conclusion

Effect of berry-based supplements and foods on cognitive function: a systematic review

In the current decade, a growing body of evidence has proposed the correlation between diet and cognitive function or dementia in the ageing population. This study was designed to appraise discoveries from the randomized controlled trials to confirm the effects of berry-based supplements or foods on cognitive function in older adults. PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Web of Science, Scopus, EMBASE, Google Scholar, and ProQuest as well as SID, Magiran, and Iranmedex electronic databases were explored for human interventional studies up to March 2021. In total, eleven articles were identified using frozen blueberry (n = 4 studies), blueberry concentrate (n = 2), beverage (n = 3), capsule (n = 1), extract and powder (n = 1). These studies had been performed among older people with no recognized cognitive impairment or mild cognitive impairment (MCI). The primary outcomes included global cognitive function, psychomotor function, learning and memory, working memory capacity, executive functions, and brain perfusion/activity. To our knowledge, this is the first systematic review of available clinical trials on the effects of berry-based supplements and foods on cognitive performances as well as brain perfusion parameters among the elderly with normal cognition or MCI. Existing evidence concludes that berry-based supplements and foods have beneficial effects on resting brain perfusion, cognitive function, memory performance, executive functioning, processing speed, and attention indices.

Enhancing the Cognitive Effects of Flavonoids With Physical Activity: Is There a Case for the Gut Microbiome?

Age-related cognitive changes can be the first indication of the progression to dementias, such as Alzheimer’s disease. These changes may be driven by a complex interaction of factors including diet, activity levels, genetics, and environment. Here we review the evidence supporting relationships between flavonoids, physical activity, and brain function. Recent in vivo experiments and human clinical trials have shown that flavonoid-rich foods can inhibit neuroinflammation and enhance cognitive performance. Improved cognition has also been correlated with a physically active lifestyle, and with the functionality and diversity of the gut microbiome. The great majority (+ 90%) of dietary flavonoids are biotransformed into phytoactive phenolic metabolites at the gut microbiome level prior to absorption, and these prebiotic flavonoids modulate microbiota profiles and diversity. Health-relevant outcomes from flavonoid ingestion may only be realized in the presence of a robust microbiome. Moderate-to-vigorous physical activity (MVPA) accelerates the catabolism and uptake of these gut-derived anti-inflammatory and immunomodulatory metabolites into circulation. The gut microbiome exerts a profound influence on cognitive function; moderate exercise and flavonoid intake influence cognitive benefits; and exercise and flavonoid intake influence the microbiome. We conclude that there is a potential for combined impacts of flavonoid intake and physical exertion on cognitive function, as modulated by the gut microbiome, and that the combination of a flavonoid-rich diet and routine aerobic exercise may potentiate cognitive benefits and reduce cognitive decline in an aging population, via mechanisms mediated by the gut microbiome. Mechanistic animal studies and human clinical interventions are needed to further explore this hypothesis.

Health Benefits of Apple Juice Consumption: A Review of Interventional Trials on Humans

Although numerous studies have reported the benefits of apple consumption on cardiometabolic health parameters and chronic disease prevention, few have focused on the effects of apple juice specifically. Juice consumption may be a convenient way to take advantage of the health effects of the bioactive components present in apples. The present review aims to summarize the current literature on health benefits of apple juice as reported in clinical trials in humans. Of the 67 studies retained, 20 interventional studies on humans were reviewed. Overall, cloudy apple juice consumption was found to be associated with several markers of cardiovascular health that may ultimately be relevant for cancer and neurodegenerative diseases. Most of the documentation was found regarding oxidative stress, as well as observations with other parameters such as markers of inflammation, lipid profile, and diabetes. This review suggests that, in 20 studies, apple juice consumed in moderation exerts positive effects on markers of cardiovascular disease risk (particularly on oxidative stress).

Anthocyanins: Traditional Uses, Structural and Functional Variations, Approaches to Increase Yields and Products' Quality, Hepatoprotection, Liver Longevity, and Commercial Products

Anthocyanins are water-soluble, colored compounds of the flavonoid class, abundantly found in the fruits, leaves, roots, and other parts of the plants. The fruit berries are prime sources and exhibit different colors. The anthocyanins utility as traditional medicament for liver protection and cure, and importance as strongest plants-based anti-oxidants have conferred these plants products different biological activities. These activities include anti-inflammation, liver protective, analgesic, and anti-cancers, which have provided the anthocyanins an immense commercial value, and has impelled their chemistry, biological activity, isolation, and quality investigations as prime focus. Methods in extraction and production of anthocyanin-based products have assumed vital economic importance. Different extraction techniques in aquatic solvents mixtures, eutectic solvents, and other chemically reactive extractions including low acid concentrations-based extractions have been developed. The prophylactic and curative therapy roles of the anthocyanins, together with no reported toxicity has offered much-needed impetus and economic benefits to these classes of compounds which are commercially available. Information retrieval from various search engines, including the PubMed^®, ScienceDirect^®, Scopus^®, and Google Scholar^®, were used in the review preparation. This imparted an outlook on the anthocyanins occurrence, roles in plants, isolation-extraction, structures, biosynthetic as well as semi- and total-synthetic pathways, product quality and yields enhancements, including uses as part of traditional medicines, and uses in liver disorders, prophylactic and therapeutic applications in liver protection and longevity, liver cancer and hepatocellular carcinoma. The review also highlights the integrated approach to yields maximizations to meet the regular demands of the anthocyanins products, also as part of the extract-rich preparations together with a listing of marketed products available for human consumption as nutraceuticals/food supplements.

Novel Nutraceutical Compounds in Alzheimer Prevention

Alzheimer’s disease (AD) incidence is increasing worldwide at an alarming rate. Considering this increase, prevention efforts, stemming from scientific research, health education, and public policies, are critical. Clinical studies evidenced that healthy lifestyles along with natural multitarget and disease-modifying agents have a preventative impact on AD or mitigate symptoms in diagnosed patients. The pathological alterations of AD start 30 years before symptoms, and it is essential to develop the capacity to detect those changes. In this regard, molecular biomarkers that detect early pathological manifestations are helpful. Based on markers data, early preventive interventions could reduce more than 40% of AD cases. Protective actions include exercise, shown to induce neurogenesis, cognitive stimulation, intellectual-social activity, and nutrition among others. Mediterranean diet, preprobiotics, and nutraceuticals containing bioactive molecules with antioxidant and anti-inflammatory properties are relevant. Antiprotein aggregation molecules whose mechanisms were described are important. Anti-inflammatory agents with anti-aggregation properties that help to control cognitive impairment, include quercetin, biocurcumin, rosemarinic acid, and Andean shilajit. Anthocyanidins, e.g., delphinidin, malvidin, and natural flavonoids, are also included. Quercetin and hydroxy-tyrosol are antiaging molecules and could have anti-AD properties. We emphasize the relevance of nutraceuticals as a main actor in the prevention and/or control of dementia and particularly AD.

Pelargonidin and Berry Intake Association with Alzheimer's Disease Neuropathology: A Community-Based Study

BACKGROUND

An anthocyanidin, pelargonidin, primarily found in berries, has antioxidant and anti-inflammatory properties, and is associated with better cognition and reduced Alzheimer's dementia risk.

OBJECTIVE

This study investigated if pelargonidin or berry intake is associated with Alzheimer's disease (AD) neuropathology in human brains.

METHODS

The study was conducted among 575 deceased participants (age at death = 91.3±6.1 years; 70% females) of the Rush Memory and Aging Project, with dietary data (assessed using a food frequency questionnaire) and neuropathological evaluations. Calorie-adjusted pelargonidin intake was modeled in quartiles and berry intake as continuous (servings/week). Mean amyloid-beta load and phosphorylated tau neuronal neurofibrillary tangle density across multiple cortical regions were assessed using immunohistochemistry. Global AD pathology burden, a quantitative summary score of neurofibrillary tangles, and diffuse and neuritic plaques using Bielschowsky silver stains in multiple brain regions, was also assessed.

RESULTS

In a linear regression model adjusted for age at death, sex, education, APOE ɛ4 status, vitamin E, and vitamin C, participants in the highest quartile of pelargonidin intake when compared to those in the lowest quartile, had less amyloid-β load (β (SE) = -0.293 (0.14), p = 0.038), and fewer phosphorylated tau tangles (β (SE) = -0.310, p = 0.051). Among APOE ɛ4 non-carriers, higher strawberry (β (SE) = -0.227 (0.11), p = 0.037) and pelargonidin (Q4 versus Q1: β (SE) = -0.401 (0.16), p = 0.011; p trend = 0.010) intake was associated with less phosphorylated tau tangles, no association was observed in APOE ɛ4 carriers. Berry intake was not associated with AD pathology. However, excluding participants with dementia or mild cognitive impairment at baseline, strawberry (p = 0.004) and pelargonidin (ptrend = 0.007) intake were associated with fewer phosphorylated tau tangles.

CONCLUSION

Higher intake of pelargonidin, a bioactive present in strawberries, is associated with less AD neuropathology, primarily phosphorylated tau tangles.

Neurocognitive Effects of Cocoa and Red-Berries Consumption in Healthy Adults

In recent decades, the elderly population has increased at higher rates than any other population group, resulting in an increase in age-related diseases such as neurodegenerative and cognitive impairment. To address this global health problem, it is necessary to search for new dietary strategies that can prevent the main neurocognitive problems associated with the ageing process. Therefore, the aim of the present study was to analyze the effect of cocoa flavanols and red berry anthocyanins on brain-derived neurotrophic factor (BDNF) and nerve growth factor receptor (NGF-R) and to stablish the possible improvement in cognitive performance by using a battery of neurocognitive tests that included the Verbal Learning Test Spain-Complutense, the Spatial Recall Test 10/36 BRB-N, the Wechsler Adult Intelligence Scale III and IV, the STROOP Task and the Tower of London Test. A randomized, double-blind, parallel-group study was performed in 60 healthy volunteers between 50 and 75 years old who consumed a cocoa powder, a red berries mixture or a combination of both for 12 weeks. After the intervention, we observed a reduction in the time needed to start (p = 0.031) and finish (p = 0.018) the neurocognitive test known as the Tower of London in all groups, but the decrease in time to finish the task was more pronounced in the intervention with the combination of cocoa-red berries group. We failed to show any significant difference in BDNF and NGF-R sera levels. However we found a negative correlation between BDNF and the number of movements required to finish the TOL in women (p = 0.044). In conclusion, our study showed an improvement in executive function, without any change in neurotrofin levels, for all intervention arms.

Bilberry/red grape juice decreases plasma biomarkers of inflammation and tissue damage in aged men with subjective memory impairment -a randomized clinical trial

BACKGROUND

Few randomized clinical trials have explored the health effects of bilberries in humans. The aim was to test the effect of bilberry and red grape-juice consumption on visual memory, motor speed and dexterity as well as inflammatory and tissue damage biomarkers of plasma in aged men with subjective memory impairment.

METHODS

Nine-week double-blind, placebo-controlled, dietary intervention study of aged men (n = 60, age ≥ 67 years) with subjective memory impairment randomized to consume a 50/50 mix of bilberry/red grape-juice or an iso-caloric placebo juice. A selection of Cambridge Cognition Test Battery (CANTAB), Grooved Pegboard tests and blood-sampling for biomarker analysis were performed before and after the intervention.

RESULTS

Compared to placebo the selected memory and motor test scores were un-affected by the bilberry/red grape intervention. However, the plasma levels of tissue damage biomarkers decreased significantly more in the bilberry/red grape group. In particular lactate dehydrogenase (LDH) decreased from 362 U/L (median, baseline) to 346 U/L (median, post intervention) in the bilberry/red grape group. Also, several biomarkers of inflammation (EGF, IL6, IL9, IL10 and TNFα) decreased significantly more in the bilberry/red grape group. Furthermore, several plasma polyphenols; p-coumaric acid, hippuric acid, protocatechuic acid, 3HPAA and vanillic acid, increased significantly more in the bilberry/red grape group compared to placebo with the largest increase in p-coumaric acid with 116%; from 2.2 [1.0,5.5] to 4.7 [2.8,8.1] μM/L (median [95% CL]).

CONCLUSIONS

The results indicate that a nine-week bilberry/red grape juice intervention has no measurable effects on the selected memory scores in aged men experiencing memory problems but decreases the level of biomarkers of inflammation and tissue damage. Whether the dampening effects on inflammation and tissue damage biomarkers have relevance for neuroinflammatory brain pathology remains to be established.

TRIAL REGISTRATION

Registration number ( ClinicalTrials.gov : NCT00972972 ), September 9, 2009.

Polyphenols and neuroprotection: Therapeutic implications for cognitive decline

Dietary polyphenols have been the focus of major interest for their potential benefits on human health. Several preclinical studies have been conducted to provide a rationale for their potential use as therapeutic agents in preventing or ameliorating cognitive decline. However, results from human studies are scarce and poorly documented. The aim of this review was to discuss the potential mechanisms involved in age-related cognitive decline or early stage cognitive impairment and current evidence from clinical human studies conducted on polyphenols and the aforementioned outcomes. The evidence published so far is encouraging but contrasting findings are to be taken into account. Most studies on anthocyanins showed a consistent positive effect on various cognitive aspects related to aging or early stages of cognitive impairment. Studies on cocoa flavanols, resveratrol, and isoflavones provided substantial contrasting results and further research is needed to clarify the therapeutic potential of these compounds. Results from other studies on quercetin, green tea flavanols, hydroxycinnamic acids (such as chlorogenic acid), curcumin, and olive oil tyrosol and derivatives are rather promising but still too few to provide any real conclusions. Future translational studies are needed to address issues related to dosage, optimal formulations to improve bioavailability, as well as better control for the overall diet, and correct target population.