Folic acid supplementation improves cognitive function by reducing the levels of peripheral inflammatory cytokines in elderly Chinese subjects with MCI

Computational phytochemical screening for Parkinson's disease therapeutics: c-Abl and beyond

Parkinson's disease (PD), a rapidly growing neurodegenerative disorder, is characterized by intracellular α-synuclein aggregates. The tyrosine kinase c-Abl plays a critical role in PD pathogenesis. This study aimed to identify novel c-Abl inhibitors from natural products using molecular docking and dynamics simulations. We explored phytochemicals from Indian Medicinal Plants, Phytochemistry and Therapeutics (IMPPAT) database and employed molecular docking and molecular dynamics to discover c-Abl inhibitors. Three potential hits: IMPHY008934, IMPHY009589, and IMPHY006310 were identified. These compounds demonstrated comparable binding affinity to Nilotinib, a comparison drug. Toxicity predictions revealed IMPHY008934 and IMPHY009589 exhibited lower toxicity than Nilotinib. Molecular dynamics simulations confirmed the stability of IMPHY009589 and IMPHY008934 with c-Abl. Density functional theory (DFT) analysis showed that IMPHY006310 and IMPHY008934 displayed enhanced reactivity and polarizability. Our findings suggest these natural compounds may target c-Abl in PD pathogenesis and possibly downregulate the overexpressed α-synuclein and may serve as promising leads for PD therapy.

The effects of methyl nutrients on cognition and one carbon metabolism in older adults with mild cognitive impairment, A systematic review and meta-analysis

BACKGROUND

Methyl nutrients can influence the one-carbon metabolic cycle and are important for cognitive function in older adults. We aimed to evaluate the effects of methyl nutrient supplementation, including the combination of folate and vitamin B12, and folate or vitamin B12 alone, on cognitive function and one-carbon metabolism in older adults with mild cognitive impairment.

METHODS

Data were retrieved and collected from six electronic databases. Two authors independently appraised the methodological quality of included studies. Network meta-analysis was performed using the Bayesian method, R software.

RESULTS

The combined intervention of folate and vitamin B12 is an effective type of nutrient intervention to slow cognitive decline in the elderly with MCI, reduce serum homocysteine concentration, and elevate serum folate and vitamin B12 concentrations.

CONCLUSION

Combining vitamin B12 plus folate supplementation is the best option for improving cognitive function in older adults with MCI.

Arsenic unsettles the cerebellar balance between neurodegeneration and neurogenesis: reversal by folic acid

Arsenic-mediated neurodegenerative disorders affect millions of individuals globally, but the specific impact of environmental arsenic on adult cerebellar degeneration and neurogenesis is incompletely understood. Of particular concern is arsenic-induced apoptosis-driven neurodegeneration. Our major objective was to investigate the molecular signaling intricacies associated with arsenic-induced death of cerebellar neurons and to propose folic acid as a possible intervention. Swiss albino mice were treated with sodium arsenite (orally: 0.05 mg/L) and folic acid (orally:10 mg/kg) for 28 days. We observed that arsenic caused noticeable cell loss with morphological alterations in cerebellum, which was remarkably restored by folic acid. Arsenic-induced morphological alterations consequently perturbed transcriptional activities of neural stem cell factors-SOX2 and KLF9, which resulted in the suppression of pro-neurogenic mediators NeuroD1, Neurogenin2, calbindin and NeuN. Interestingly, folic acid reversed the expression of these critical pro-neurogenic mediators to mitigate these degenerative changes to promote neurogenesis. Delving deep, we found that folic acid rescued arsenic-exposed cerebellum from severe oxidative and pro-inflammatory insults by increasing antioxidants like SOD, Catalase, GSH, upregulating Nrf2 and downregulating M1 macrophages, JNK, NF-κB, and STAT3 activities. For the first time, we are reporting that arsenic induced a G1/S cell cycle arrest and triggered apoptosis in mouse cerebellum by activating the p53-p21 axis, downregulating CDKs and instigated p21-mediated suppression of SOX2 transcriptional activity. Folic acid abated such alterations by modulating the p53/p21/SOX2 axis. Collectively, the anti-apoptotic and pro-neurogenic effects of folic acid present it as a promising therapeutic candidate, warranting further research into its efficacy against metal-induced neurodegenerative disorders.

Short-Term Effects of Folate Supplementation in Combination With Vitamin B6 for Treating Acute Manic Episodes in Bipolar I Disorder: A Randomized Controlled Trial

BACKGROUND

Drug resistance poses a formidable challenge in managing acute manic episodes in bipolar I disorder, leading to suboptimal treatment outcomes. This study investigates the efficacy of folate and vitamin B6 supplementation as an adjunct to sodium valproate in improving treatment responses for patients experiencing acute mania.

METHODS

In a randomized, double-blind, placebo-controlled trial, 43 patients diagnosed with bipolar I disorder presenting with acute manic episodes were enrolled. Participants were randomly assigned to three groups: one receiving folate (5 mg/day) plus vitamin B6 (80 mg/day), a second group receiving folate alone (5 mg/day), and a third group receiving placebo. Evaluations were conducted at baseline and after 3 and 6 weeks using the Mini-Mental State Examination (MMSE) and the Young Mania Rating Scale (YMRS).

RESULTS

All groups demonstrated significant clinical improvements after the treatment period; however, the trends in MMSE scores showed no significant differences (p = 0.068). Notably, the reduction in YMRS scores significantly varied across groups (p < 0.001, effect size = 0.342), with the folate group demonstrating a significantly greater decrease compared to both the folate/B6 (p = 0.003) and placebo groups (p < 0.001). Recovery rates revealed that 80% of patients receiving folate showed over a 50% decrease in YMRS scores after 3 weeks, markedly higher than the other groups (p = 0.001).

CONCLUSIONS

Our findings support the short-term use of folate as a beneficial adjunct in treating acute manic episodes in bipolar I disorder. However, the addition of vitamin B6 did not yield additional advantages. These results may inform future treatment guidelines targeting acute mania in bipolar disorder, advocating for folate supplementation as a potential strategy to enhance therapeutic outcomes.

Utilisation of Carbon Quantum Dots from Hazelnut Husk for Folic Acid (FA) Detection: An Innovative Approach

This study presents the development of a carbon quantum dot (CQD)-based fluorescence sensor for the accurate quantification of Folic Acid (FA). CQDs were synthesized from hazelnut husk using a solvothermal method and functionalized with silver ions to create an "off-state" fluorescence system. Upon mixing FA solutions, prepared from pure water and pharmaceutical tablets, with phosphate-buffered saline (PBS) and "off-state" CQDs, fluorescence emission was restored ("on-state") in a concentration-dependent manner when excited at 360 nm. A strong linear relationship was observed between FA concentration and fluorescence intensity, with an R² value of ≈ 0.994. The samples were categorized into low (0.0376-0.7533 µM) and high (0.7533-7.533 µM) concentration groups for improved accuracy, achieving mean percentage errors of 0.70% and 1.85%, respectively, at concentrations as low as 0.565 µM. This CQD-based sensor demonstrated rapid, cost-effective, and highly sensitive detection capabilities, making it a promising alternative for FA quantification in biomedical and nutritional applications. Furthermore, the use of sustainable raw materials, such as hazelnut husk, highlights the eco-friendly and practical advantages of this method over conventional techniques.

Cardiovascular disease attenuates the protective effect of folate on global cognitive function in an elderly population: a cross-sectional study

Research suggests that folic acid contributes to improving cognitive function. However, there is a lack of systematic research on the association of dietary intake of folate and serum, and red blood cell (RBC) folate levels with global cognitive impairment (CoI) in the elderly population. Importantly, excessive supplementation with folate among American adults at high risk of cardiovascular disease (CVD) may have harmful effects. CVD often leads to worse cognitive function; therefore, it is necessary to explore the characteristics of the association of folate with CoI in both CVD and non-CVD populations. Participants aged ≥ 60 years from the national health and nutrition examination survey (NHANES) 2011-2014 were included. Dietary intake of folate and serum and RBC folate levels were determined through questionnaires or laboratory measurements. Global cognitive function was assessed via the results of three cognitive assessments. Multivariable logistic regression and restricted cubic splines (RCS) were employed to assess the odds ratios (ORs), 95% confidence intervals (CIs), and potential non-linearities of folate with cognition. Additionally, the interaction term of CVD with RBC folate was included in the model, and effect modification was detected through likelihood ratio tests. Finally, several sensitivity analyses were conducted to validate our findings. This study included 2104 participants with complete data and a median age of 68 years, with females comprising 51% of the participants. Of the participants, 444 individuals were defined as having CoI. In the NHANES, Pearson correlation analysis revealed moderate to weak correlations between dietary, serum, and RBC folate levels and CoI (all < 0.6). In addition, when different sources of folate were included separately in the models, fully adjusted logistic regression with continuous variables included in the model revealed that only RBC folate was significantly associated with CoI [odds ratio (OR) 0.86, 95% confidence interval (95% CI) 0.75-0.97, P = 0.02]. According to tertile groups, compared with participants in the lowest tertile, individuals in the highest tertile of total dietary folate levels (OR 0.67, 95% CI 0.48-0.94, P = 0.02), folic acid levels (OR 0.57, 95% CI 0.38-0.86, P = 0.01), and RBC folate levels (OR 0.62, 95% CI 0.44-0.85, P = 0.004) had significantly lower odds of having CoI. The RCS showed a linear negative correlation between RBC folate levels and CoI. Furthermore, interaction analysis suggested that CVD attenuated the protective effect of RBC folate. Several sensitivity analyses also suggested a modifying effect of CVD on the association between RBC folate and CoI. A significant negative correlation exists between RBC folate levels and CoI in the elderly population of the United States, and this association is stronger than that of other folate measures. However, the protective effect of RBC folate on CoI is negated in patients with CVD, and further investigation is needed to explore the underlying mechanisms involved.

Folate and vitamin B12 supplementation in patients with schizophrenia and low serum folate level: A 24-week randomized, double-blind, placebo-controlled study

PURPOSE

We aimed to evaluate the effects of folate and vitamin B12 on psychopathology in patients with schizophrenia and low serum folate levels.

METHODS

Fifty-five schizophrenia patients with serum folate levels lower than 6 mg/L were randomized in a 2:1 ratio to supplementation with 5 mg of folate and 500 μg of vitamin B12 per day (the folate group, n = 36) or placebo (the placebo group, n = 19) for 24 weeks. We evaluated patients' symptomatology with the Positive and Negative Symptom Scale (PANSS) and cognitive functions with Cogstate.

RESULTS

During the 24-week intervention, serum folate and vitamin B12 levels significantly increased, and homocysteine level significantly decreased in the folate group, but these markers did not significantly change in the placebo group. There were no significant changes in scores of total and each subscale of PANSS, and Cogstate between the folate and placebo groups. A subgroup analysis within the folate groups revealed no significant differences in the changes of psychotic symptoms severity or cognitive functions among patients with different degrees of folate level increments.

CONCLUSION

Our finding suggested that the extent of increased folate levels did not exert a notable impact on the changes of psychotic symptoms severity or cognitive function in our patients. It may also due to the relatively stable condition in our recruited patients, so supplementation of folate cannot show its effectiveness. Whether folate can improve psychopathology in moderate to severe patients with schizophrenia should be evaluated with a larger sample size in the future.

An overview of the relationship between inflammation and cognitive function in humans, molecular pathways and the impact of nutraceuticals

Inflammation has been associated with cognitive decline, whether in the peripheral or central nervous systems. The primary mechanism involves the response of microglia, an immune cell in the brain, which generates pro-inflammatory mediators such as cytokines, chemokines, and adhesion molecules. The excessive production of pro-inflammatory mediators may accelerate the damage to neurons, contributing to the development of neurodegenerative diseases such as Alzheimer's disease, mild cognitive impairment, and vascular dementia, as well as a general decline in cognitive function. Various studies have supported the correlation between elevated pro-inflammatory mediators and a decline in cognitive function, particularly in aging and age-related neurodegenerative diseases. Moreover, this association has also been observed in other inflammatory-related conditions, including post-operative cognitive impairment, diabetes, stroke, obesity, and cancer. However, the interaction between inflammatory processes and cognitive function in humans remains unclear and varies according to different health conditions. Therefore, this review aims to consolidate and evaluate the available evidence from original studies as well as meta-analyses in order to provide a greater understanding of the inflammatory process in connection with cognitive function in humans. Furthermore, relevant biological cellular processes, putative inflammatory biomarkers, and the role of nutraceuticals on the interaction between cognitive performance and inflammatory status are outlined.

Effects of folic acid supplementation on cognitive function and inflammation in elderly patients with mild cognitive impairment: A systematic review and meta-analysis of randomized controlled trials

OBJECT

The aim was to assess the effect of folic acid supplementation on cognitive function and inflammatory cytokines in elderly patients with mild cognitive impairment.

METHODS

From its inception until February 2024, four databases including Web of Science were searched. Two researchers independently screened the literature, assessed the quality, extracted data, and conducted a meta-analysis using RevMan.

RESULTS

The systematic review included seven studies (with a total of 1102 participants, mean age 65-80 years), seven of which were appropriate for meta-analysis. Although a small number of studies found relatively large heterogeneity, the majority of studies showed significant benefit from folic acid supplementation, including the FSIQ (823 individuals, standardized mean difference [SMD] = 8.36, 95 % confidence interval [CI] = 0.79 - 1.08), Arithmetic (823 individuals, SMD = 0.17, 95 % CI = -0.03-0.31), Information, SMD = 1.73, 95 % CI 0.41-3.05), Digit Span (823 individuals, SMD = 0.17, 95 % CI = -0.03 - 0.31), Block Design (823 individuals, SMD = 0.26, 95 % CI 0.03-0.49), Picture Completion (823 individuals, SMD = 0.27, 95 % CI = -0.15 - 0.69) and Picture Arrangement (823 individuals, SMD = -0.12, 95 % CI = -0.26 - 0.01). Finally, folic acid supplementation had a significant effect on the reduction of most inflammatory cytokines, blood biomarkers of Alzheimer's disease, and Hcy.

CONCLUSIONS

Folic acid supplementation seems to have a positive impact on cognitive function in older adults with mild cognitive impairment, but further evidence of its effectiveness in improving inflammatory cytokines is needed from high-quality studies.

Epigenetic Explorations of Neurological Disorders, the Identification Methods, and Therapeutic Avenues

Neurodegenerative disorders are major health concerns globally, especially in aging societies. The exploration of brain epigenomes, which consist of multiple forms of DNA methylation and covalent histone modifications, offers new and unanticipated perspective into the mechanisms of aging and neurodegenerative diseases. Initially, chromatin defects in the brain were thought to be static abnormalities from early development associated with rare genetic syndromes. However, it is now evident that mutations and the dysregulation of the epigenetic machinery extend across a broader spectrum, encompassing adult-onset neurodegenerative diseases. Hence, it is crucial to develop methodologies that can enhance epigenetic research. Several approaches have been created to investigate alterations in epigenetics on a spectrum of scales-ranging from low to high-with a particular focus on detecting DNA methylation and histone modifications. This article explores the burgeoning realm of neuroepigenetics, emphasizing its role in enhancing our mechanistic comprehension of neurodegenerative disorders and elucidating the predominant techniques employed for detecting modifications in the epigenome. Additionally, we ponder the potential influence of these advancements on shaping future therapeutic approaches.

Unveiling the Therapeutic Potential of Folate-Dependent One-Carbon Metabolism in Cancer and Neurodegeneration

Cellular metabolism is crucial for various physiological processes, with folate-dependent one-carbon (1C) metabolism playing a pivotal role. Folate, a B vitamin, is a key cofactor in this pathway, supporting DNA synthesis, methylation processes, and antioxidant defenses. In dividing cells, folate facilitates nucleotide biosynthesis, ensuring genomic stability and preventing carcinogenesis. Additionally, in neurodevelopment, folate is essential for neural tube closure and central nervous system formation. Thus, dysregulation of folate metabolism can contribute to pathologies such as cancer, severe birth defects, and neurodegenerative diseases. Epidemiological evidence highlights folate's impact on disease risk and its potential as a therapeutic target. In cancer, antifolate drugs that inhibit key enzymes of folate-dependent 1C metabolism and strategies targeting folate receptors are current therapeutic options. However, folate's impact on cancer risk is complex, varying among cancer types and dietary contexts. In neurodegenerative conditions, including Alzheimer's and Parkinson's diseases, folate deficiency exacerbates cognitive decline through elevated homocysteine levels, contributing to neuronal damage. Clinical trials of folic acid supplementation show mixed outcomes, underscoring the complexities of its neuroprotective effects. This review integrates current knowledge on folate metabolism in cancer and neurodegeneration, exploring molecular mechanisms, clinical implications, and therapeutic strategies, which can provide crucial information for advancing treatments.

A combination of chlorzoxazone and folic acid improves recognition memory, anxiety and depression in SCA3-84Q mice

Spinocerebellar ataxia type 3 (SCA3), also known as Machado-Joseph disease, is reported to be the most common type of autosomal dominant cerebellar ataxia (ADCA). SCA3 patients suffer from a progressive decline in motor coordination and other disease-associated symptoms. Moreover, recent studies have reported that SCA3 patients also exhibit symptoms of cerebellar cognitive affective syndrome (CCAS). We previously observed signs of CCAS in mouse model of SCA3. Particularly, SCA3-84Q mice suffer from anxiety, recognition memory decline, and also exhibit signs of low mood and aversion to activity. Here we studied the effect of long-term injections of SK channels activator chlorzoxazone (CHZ) together and separately with the folic acid (FA) on the cerebellar Purkinje cell (PC) firing and histology, and also on the motor and cognitive functions as well as mood alterations in SCA3-84Q hemizygous transgenic mice. We realized that both CHZ and CHZ-FA combination had similar positive effect on pure cerebellum impairments including PC firing precision, PC histology, and motor performance in SCA3-84Q mice. However, only the CHZ-FA combination, but not CHZ, had significantly ameliorated the signs of anxiety and depression, and also noticeably improved recognition memory in SCA3-84Q mice. Our results suggest that the combination therapy for both ataxia and non-motor symptoms is required for the complex treatment of ADCA.

Probiotics and the microbiota-gut-brain axis in neurodegeneration: Beneficial effects and mechanistic insights

Neurodegenerative diseases (NDs) are a group of heterogeneous disorders with a high socioeconomic burden. Although pharmacotherapy is currently the principal therapeutic approach for the management of NDs, mounting evidence supports the notion that the protracted application of available drugs would abate their dopaminergic outcomes in the long run. The therapeutic application of microbiome-based modalities has received escalating attention in biomedical works. In-depth investigations of the bidirectional communication between the microbiome in the gut and the brain offer a multitude of targets for the treatment of NDs or maximizing the patient's quality of life. Probiotic administration is a well-known microbial-oriented approach to modulate the gut microbiota and potentially influence the process of neurodegeneration. Of note, there is a strong need for further investigation to map out the mechanistic prospects for the gut-brain axis and the clinical efficacy of probiotics. In this review, we discuss the importance of microbiome modulation and hemostasis via probiotics, prebiotics, postbiotics and synbiotics in ameliorating pathological neurodegenerative events. Also, we meticulously describe the underlying mechanism of action of probiotics and their metabolites on the gut-brain axis in different NDs. We suppose that the present work will provide a functional direction for the use of probiotic-based modalities in promoting current practical treatments for the management of neurodegenerative-related diseases.

Cognitive Benefits of Folic Acid, Docosahexaenoic Acid, and a Combination of Both Nutrients in Mild Cognitive Impairment: Possible Alterations through Mitochondrial Function and DNA Damage

INTRODUCTION

It is uncertain whether folic acid (FA) combined with docosahexaenoic acid (DHA) could improve cognitive performance. This study evaluated the effects of a 12-month FA and DHA supplementation, in combination or alone, on cognitive function, DNA oxidative damage, and mitochondrial function in participants with mild cognitive impairment (MCI).

METHODS

This randomized, double-blind, placebo-controlled trial recruited MCI participants aged 60 years and older. Two hundred and eighty participants were randomly divided in equal proportion into four groups: FA + DHA (FA 800 μg/d + DHA 800 mg/d), FA (800 μg/d), DHA (800 mg/d), and placebo groups daily orally for 12 months. The primary outcome was cognitive function evaluated by the Wechsler Adult Intelligence Scale-Revised (WAIS-RC). Cognitive tests and blood mechanism-related biomarkers were determined at baseline and 12 months.

RESULTS

During the 12-month follow-up, scores of full intelligence quotient (βDHA: 1.302, 95% CI: 0.615, 1.990, p < 0.001; βFA: 1.992, 95% CI: 1.304, 2.679, p < 0.001; βFA+DHA: 2.777, 95% CI: 2.090, 3.465, p < 0.001), verbal intelligence quotient, and some subtests of the WAIS-RC were significantly improved in FA + DHA and single intervention groups compared to the placebo group. Moreover, the FA and DHA intervention combination was superior to either intervention alone (p < 0.001). Meanwhile, FA, DHA, and their combined use significantly decreased 8-OHdG level and increased mitochondrial DNA copy number compared to the placebo (p < 0.05).

CONCLUSIONS

Supplementation of FA and DHA, alone or combined, for 12 months can improve cognitive function in MCI participants, possibly through mitigating DNA oxidative damage and enhancing mitochondrial function. Combined supplementation may provide more cognitive benefit than supplementation alone.

A Comparative Study Evaluating the Effectiveness of Folate-Based B Vitamin Intervention on Cognitive Function of Older Adults under Mandatory Folic Acid Fortification Policy: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The policies regarding the mandatory fortification of food with folic acid (FA) may impact the effectiveness of folate-based B vitamin treatment on cognitive function in older adults. We critically and systematically review the literature to assess whether food fortification policies affect folate-based B vitamin treatment efficacy on cognition function in older adults. Electronic databases, including PubMed, Web of Science, and CNKI, were searched for "Cognitive Function", "Folate", and "Older Adults". The study had specific criteria for inclusion, which were as follows: (1) the studies should initially have randomized controlled trials that were conducted on older adults aged 60 or above; (2) the studies must assess the relationship between folate status and cognitive performance; and (3) the studies should clarify the policies regarding food fortification with FA. This review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guidelines. Two reviewers independently extracted all the data, and any discrepancies were resolved by consensus. All the data collected were compiled, compared, and analyzed critically. Random effects models were used to assess the effects of interventions. The systematic review included fifty-one articles involving 42,768 participants. Of these, the 23 articles were included in the meta-analysis. The meta-analysis on the effects of folate-based B vitamin supplementation on cognitive function showed a significant overall impact (Z = 3.84; p = 0.0001; SMD, 0.18; 95% CI, 0.09, 0.28). Further analysis revealed that FA food fortification policies were not implemented in countries where folate-based B vitamin supplementation improved cognitive impairment in older adults (Z = 3.75; p = 0.0002; SMD, 0.27; 95% CI, 0.13, 0.40). However, the FA intervention did not have significant outcomes in areas where FA food fortification policies were mandatory (Z = 0.75; p = 0.45; SMD, 0.03; 95% CI, -0.06, 0.13). Supplementing with oral folic acid, alone or in combination, has been linked to improved cognitive performance in older adults. While mandatory FA fortification has the improved folic acid status, additional folate-based B vitamin supplements do not appear to influence cognitive function.

Impact of vegetarianism on cognition and neuropsychological status among urban community-dwelling adults in Telangana, South India: a cross-sectional study

PURPOSE

The potential benefits of vegetarian diets in reducing cognitive impairment have garnered attention due to existing mixed results; hence, our study aims to examine the impact of vegetarianism on cognitive function and neuropsychological status among urban community-dwelling adults from Telangana.

METHODS

The dietary patterns were self-reported and dietary data collected using a Food Frequency Questionnaire while cognitive function was assessed using Mini-Mental State Examination (MMSE) and depression, anxiety, and stress (DASS-21) questionnaire for psychological measures. Adults (N = 304) aged 40 years and above, who followed either a vegetarian or non-vegetarian diet for at least 6 months prior to data collection, scored MMSE ≥ 19 indicating mild cognitive impairment, and were recruited using convenience sampling.

RESULTS

Among the participants, vegetarians (n = 155) exhibited significantly better mood states compared to non-vegetarians (n = 149), as indicated by lower scores on the DASS subscales for depression (10.0 ± 0.06 vs. 17.0 ± 0.07, p =  < 0.001), anxiety (4.0 ± 0.05 vs. 6.0 ± 0.07, p = 0.005), and stress (8.0 ± 0.02 vs. 10.0 ± 0.05, p = 0.007). Vegetarians also demonstrated superior cognitive functioning compared to non-vegetarians, as indicated by higher MMSE scores (26.0 ± 0.04 vs. 24.0 ± 0.03, p =  < 0.001). MMSE scores were inversely correlated with depression, anxiety, and stress for vegetarians (ρ = - 0.371, p = 0.000; ρ = - 0.027, p = 0.734; and ρ = - 0.105, p = 0.914), respectively. Similar to the vegetarians group, MMSE scores were negatively correlated with depression (ρ = - 0.059), but the correlation is not significant.

CONCLUSION

Vegetarianism exerted a positive influence on the cognitive and neuropsychological status of the investigated population. Nevertheless, additional research is required to comprehend the underlying mechanisms that elucidate the long-term effects of vegetarianism and plant-based nutritional interventions on brain health.

Vascular dementia: From pathobiology to emerging perspectives

Vascular dementia (VaD) is the second most common type of dementia. VaD is synonymous with ageing, and its symptoms place a significant burden on the health and wellbeing of older people. Despite the identification of a substantial number of risk factors for VaD, the pathological mechanisms underpinning this disease remain to be fully elucidated. Consequently, a biogerontological imperative exists to highlight the modifiable lifestyle factors which can mitigate against the risk of developing VaD. This review will critically examine some of the factors which have been revealed to modulate VaD risk. The survey commences by providing an overview of the putative mechanisms which are associated with the pathobiology of VaD. Next, the factors which influence the risk of developing VaD are examined. Finally, emerging treatment avenues including epigenetics, the gut microbiome, and pro-longevity pharmaceuticals are discussed. By drawing this key evidence together, it is our hope that it can be used to inform future experimental investigations in this field.

Targeting epigenetics: A novel promise for Alzheimer's disease treatment

So far, the search for a cure for Alzheimer Disease (AD) has been unsuccessful. The only approved drugs attenuate some symptoms, but do not halt the progress of this disease, which affects 50 million people worldwide and will increase its incidence in the coming decades. Such scenario demands new therapeutic approaches to fight against this devastating dementia. In recent years, multi-omics research and the analysis of differential epigenetic marks in AD subjects have contributed to our understanding of AD; however, the impact of epigenetic research is yet to be seen. This review integrates the most recent data on pathological processes and epigenetic changes relevant for aging and AD, as well as current therapies targeting epigenetic machinery in clinical trials. Evidence shows that epigenetic modifications play a key role in gene expression, which could provide multi-target preventative and therapeutic approaches in AD. Both novel and repurposed drugs are employed in AD clinical trials due to their epigenetic effects, as well as increasing number of natural compounds. Given the reversible nature of epigenetic modifications and the complexity of gene-environment interactions, the combination of epigenetic-based therapies with environmental strategies and drugs with multiple targets might be needed to properly help AD patients.

Roles of Oxidative Stress in Synaptic Dysfunction and Neuronal Cell Death in Alzheimer's Disease

Alzheimer's disease (AD) is a brain disorder that progressively undermines memory and thinking skills by affecting the hippocampus and entorhinal cortex. The main histopathological hallmarks of AD are the presence of abnormal protein aggregates (Aβ and tau), synaptic dysfunction, aberrant proteostasis, cytoskeletal abnormalities, altered energy homeostasis, DNA and RNA defects, inflammation, and neuronal cell death. However, oxidative stress or oxidative damage is also evident and commonly overlooked or considered a consequence of the advancement of dementia symptoms. The control or onset of oxidative stress is linked to the activity of the amyloid-β peptide, which may serve as both antioxidant and pro-oxidant molecules. Furthermore, oxidative stress is correlated with oxidative damage to proteins, nucleic acids, and lipids in vulnerable cell populations, which ultimately lead to neuronal death through different molecular mechanisms. By recognizing oxidative stress as an integral feature of AD, alternative therapeutic or preventive interventions are developed and tested as potential or complementary therapies for this devastating neurodegenerative disease.

A chlorzoxazone-folic acid combination improves cognitive affective decline in SCA2-58Q mice

Spinocerebellar ataxia type 2 (SCA2) is a polyglutamine disorder caused by a pathological expansion of CAG repeats in ATXN2 gene. SCA2 is accompanied by cerebellar degeneration and progressive motor decline. Cerebellar Purkinje cells (PCs) seem to be primarily affected in this disorder. The majority of the ataxia research is focused on the motor decline observed in ataxic patients and animal models of the disease. However, recent evidence from patients and ataxic mice suggests that SCA2 can also share the symptoms of the cerebellar cognitive affective syndrome. We previously reported that SCA2-58Q PC-specific transgenic mice exhibit anxiolytic behavior, decline in spatial memory, and a depressive-like state. Here we studied the effect of the activation of the small conductance calcium-activated potassium channels (SK channels) by chlorzoxazone (CHZ) combined with the folic acid (FA) on the PC firing and also motor, cognitive and affective symptoms in SCA2-58Q mice. We realized that CHZ-FA combination improved motor and cognitive decline as well as ameliorated mood alterations in SCA2-58Q mice without affecting the firing rate of their cerebellar PCs. Our results support the idea of the combination therapy for both ataxia and non-motor symptoms in ataxic mice without affecting the firing frequency of PCs.

Methyl donor supplementation reduces phospho-Tau, Fyn and demethylated protein phosphatase 2A levels and mitigates learning and motor deficits in a mouse model of tauopathy

BACKGROUND

Reduced folate status and elevated levels of circulating homocysteine are modifiable risk factors for cognitive decline and dementia. Disturbances in one-carbon metabolism are associated with the pathological accumulation of phosphorylated tau, a hallmark feature of prevalent dementia, including Alzheimer's disease and subgroups of frontotemporal dementia.

METHODS

Here, using transgenic TAU58/2 mouse models of human tauopathy, we tested whether dietary supplementation with L-methylfolate (the active folate form), choline and betaine can reduce tau phosphorylation and associated behavioural phenotypes.

RESULTS

TAU58/2 mice fed with the methyl donor-enriched diet showed reduced phosphorylation of tau at the pathological S202 (CP13) and S396/S404 (PHF-1) epitopes and alleviation of associated motor and learning deficits. Compared with mice on the control diet, the decrease in cortical phosphorylated tau levels in mice fed with the methyl donor-enriched diet was associated with enhanced methylation of protein phosphatase 2A, the major brain tau Ser/Thr phosphatase. It also correlated with a reduction in protein levels of Fyn, a tau tyrosine kinase that plays a central role in mediating pathological tau-induced neurodegeneration. Conversely, Fyn expression levels were increased in mice with deficiencies in folate metabolism.

CONCLUSIONS

Our findings provide the first experimental evidence that boosting one-carbon metabolism with L-methylfolate, choline and betaine can mitigate key pathological, learning and motor deficits in a tauopathy mouse model. They give support to using a combination of methyl donors as a preventive or disease-modifying strategy for tauopathies.

Alzheimer's Disease Treatment: The Search for a Breakthrough

As the search for modalities to cure Alzheimer's disease (AD) has made slow progress, research has now turned to innovative pathways involving neural and peripheral inflammation and neuro-regeneration. Widely used AD treatments provide only symptomatic relief without changing the disease course. The recently FDA-approved anti-amyloid drugs, aducanumab and lecanemab, have demonstrated unclear real-world efficacy with a substantial side effect profile. Interest is growing in targeting the early stages of AD before irreversible pathologic changes so that cognitive function and neuronal viability can be preserved. Neuroinflammation is a fundamental feature of AD that involves complex relationships among cerebral immune cells and pro-inflammatory cytokines, which could be altered pharmacologically by AD therapy. Here, we provide an overview of the manipulations attempted in pre-clinical experiments. These include inhibition of microglial receptors, attenuation of inflammation and enhancement of toxin-clearing autophagy. In addition, modulation of the microbiome-brain-gut axis, dietary changes, and increased mental and physical exercise are under evaluation as ways to optimize brain health. As the scientific and medical communities work together, new solutions may be on the horizon to slow or halt AD progression.

Natural Bioactive Products as Epigenetic Modulators for Treating Neurodegenerative Disorders

Neurodegenerative disorders (NDDs) are major health issues in Western countries. Despite significant efforts, no effective therapeutics for NDDs exist. Several drugs that target epigenetic mechanisms (epidrugs) have been recently developed for the treatment of NDDs, and several of these are currently being tested in clinical trials. Furthermore, various bioproducts have shown important biological effects for the potential prevention and treatment of these disorders. Here, we review the use of natural products as epidrugs to treat NDDs in order to explore the epigenetic effects and benefits of functional foods and natural bioproducts on neurodegeneration.

Surfeit folic acid, protein, and exercise modify oncogenic inflammatory biomarkers and fecal microbiota

Intestinal microbiota, diet, and physical activity are inextricably linked to inflammation occurring in the presence of tumor progression and declining neurocognition. This study aimed to explore how fecal microbiota, inflammatory biomarkers, and neurocognitive behavior are influenced by voluntary exercise and surplus dietary protein and folic acid which are common health choices. Dietary treatments provided over 8 weeks to C57BL/CJ male mice (N = 76) were: Folic Acid (FA) Protein (P) Control (FPC, 17.9% P; 2 mgFA/kg); Folic Acid Deficient (FAD); Folic Acid Supplemented (FAS; 8 mgFA/kg); Low Protein Diet (LPD, 6% P); and High Protein Diet (HPD, 48% P). FAS mice had decreased plasma HCys (p < 0.05), therefore confirming consumption of FA. Objectives included examining influence of exercise using Voluntary Wheel Running (VWR) upon fecal microbiota, inflammatory biomarkers C - reactive protein (CRP), Vascular Endothelial Growth Factor (VEGF), Interleukin-6 (IL-6), nuclear factor kappa ß subunit (NF-κßp65), Caspase-3 (CASP3), Tumor Necrosis Factor-alpha (TNF-α), and neurocognitive behavior. CRP remained stable, while a significant exercise and dietary effect was notable with decreased VEGF (p < 0.05) and increased CASP3 (p < 0.05) for exercised HPD mice. Consumption of FAS did significantly increase (p < 0.05) muscle TNF-α and the ability to build a nest (p < 0.05) was significantly decreased for both FAD and LPD exercised mice. Rearing behavior was significantly increased (p < 0.05) in mice fed HPD. An emerging pattern with increased dietary protein intake revealed more distance explored in Open Field Testing. At week 1, both weighted and unweighted UniFrac principal coordinates analysis yielded significant clustering (permanova, p ≤ 0.05) associated with the specific diets. Consumption of a HPD diet resulted in the most distinct fecal microbiota composition. At the phylum level-comparing week 1 to week 8-we report a general increase in the Firmicutes/Bacteroidetes ratio, characterized by an outgrowth of Firmicutes by week 8 in all groups except the HPD. MaAsLin2 analysis corroborates this finding and emphasizes an apparent inversion of the microbiome composition at week 8 after HPD. Explicit modification of oncogenic inflammatory biomarkers and fecal microbiome post high FA and protein intake along with voluntary exercise contributed to current underlying evidence that this diet and exercise relationship has broader effects on human health and disease-perhaps importantly as a practical modulation of cancer progression and declining neurocognition.

Cognitive changes are associated with increased blood-brain barrier leakage in non-brain metastases lung cancer patients

To explore the relationship between cognitive function and blood-brain barrier leakage in non-brain metastasis lung cancer and healthy controls. 75 lung cancers without brain metastasis and 29 healthy controls matched with age, sex, and education were evaluated by cognitive assessment, and the Patlak pharmacokinetic model was used to calculate the average leakage in each brain region according to the automated anatomical labeling atlas. After that, the relationships between cognitive and blood-brain barrier leakage were evaluated. Compared with healthy controls, the leakage of bilateral temporal gyrus and whole brain gyrus were higher in patients with lung cancers (P < 0.05), mainly in patients with advanced lung cancer (P < 0.05), but not in patients with early lung cancer (P > 0.05). The cognitive impairment of advanced lung cancers was mainly reflected in the damage of visuospatial/executive, and delayed recall. The left temporal gyrus with increased blood-brain barrier leakage showed negative correlations with delayed recall (r = -0.201, P = 0.042). An increase in blood-brain barrier leakage was found in non-brain metastases advanced lung cancers that corresponded to decreased delayed recall. With progression in lung cancer staging, blood-brain barrier shows higher leakage and may lead to brain metastases and lower cognitive development.

The Role of Nutrition on Meta-inflammation: Insights and Potential Targets in Communicable and Chronic Disease Management

PURPOSE OF REVIEW

Chronic low-grade inflammation may contribute to the onset and progression of communicable and chronic diseases. This review examined the effects and eventual mediation roles of different nutritional factors on inflammation.

RECENT FINDINGS

Potential nutritional compounds influencing inflammation processes include macro and micronutrients, bioactive molecules (polyphenols), specific food components, and culinary ingredients as well as standardized dietary patterns, eating habits, and chrononutrition features. Therefore, research in this field is still required, taking into account critical aspects of heterogeneity including type of population, minimum and maximum intakes and adverse effects, cooking methods, physiopathological status, and times of intervention. Moreover, the integrative analysis of traditional variables (age, sex, metabolic profile, clinical history, body phenotype, habitual dietary intake, physical activity levels, and lifestyle) together with individualized issues (genetic background, epigenetic signatures, microbiota composition, gene expression profiles, and metabolomic fingerprints) may contribute to the knowledge and prescription of more personalized treatments aimed to improving the precision medical management of inflammation as well as the design of anti-inflammatory diets in chronic and communicable diseases.

Does folic acid supplementation have a positive effect on improving memory? A systematic review and meta-analysis of randomized controlled trials

Introduction

The results of randomized controlled trials (RCTs) on the effect of folic acid supplementation on memory status due to various heterogeneity, dosage, duration, and cognitive function assessments were inconclusive. Therefore, we have performed a systematic review and meta-analysis to investigate the effect of folic acid supplementation on memory in RCTs.

Method

Comprehensive computerized systematic searches were conducted throughout Scopus, PubMed/Medline, and Google Scholar from inception until February 2022 to investigate the effect of folic acid supplementation memory levels in RCTs. The standardized mean difference (SMD) and 95% confidence interval (CIs) were used to estimate the overall effect size using random-effects meta-analyses.

Results

The overall results of nine trials with 641 participants, revealed that folic acid supplementation did not significantly change memory score compared to placebo (SMD: 0.12; 95% CI: -0.17, 0.40, p = 0.418; I 2 = 62.6%). However, subgroup analyses showed that supplementation with folic acid had favorable effects on memory levels considering the following conditions: (1) doses lower than 1 mg/day, (2) treatment lasting more than 6 months, (3) conducted in eastern countries, and (4) in participants equal to or older than 70 years old. The dose-response analysis suggested a significant favorable effect on memory status at doses of 6-11 mg/d and a significant decline at doses of 17-20 mg/d.

Discussion

Although we did not find a significant effect of folic acid supplementation on memory, there were some suggestions of beneficial effects in the subgroup analyses.

Nutrients and amyloid β status in the brain: A narrative review

Amyloid beta (Aβ) is a peptide and a hallmark of Alzheimer's disease (AD). Emerging evidence suggests that Aβ levels could be influenced by diet. However, the evidence is sparse and for some nutrients, controversial. The aim of this narrative review is to gather the findings of observational and clinical trials involving human participants on the relationships between nutrients and brain Aβ status. Some dietary patterns are associated to reduced levels of Aβ in the brain, such as the Mediterranean diet, ketogenic diet as well as low intake of saturated fat, high-glycemic-index food, sodium, and junk/fast food. Low Aβ status in the brain was also associated with higher density lipoproteins (HDL) cholesterol and polyunsaturated fatty acids consumption. Data on alcohol intake is not conclusive. On the contrary, high Aβ levels in the brain were related to a higher intake of total cholesterol, triglycerides, low-density lipoproteins (LDL) cholesterol, saturated fat, sucrose, and fructose. Folic acid, cobalamin, vitamin E, and vitamin D were not associated to Aβ status, while high blood concentrations of Calcium, Aluminum, Zinc, Copper, and Manganese were associated with decreased Aβ blood levels but were not associated with Aβ cerebral spinal fluid (CSF) concentrations. In conclusion, certain dietary patterns and nutrients are associated to brain Aβ status. Further research on the association between nutrients and brain Aβ status is needed in order to pave the way to use nutritional interventions as efficacious strategies to prevent Aβ disturbance and potentially AD.

Folic Acid Improves Parkin-Null Drosophila Phenotypes and Transiently Reduces Vulnerable Dopaminergic Neuron Mitochondrial Hydrogen Peroxide Levels and Glutathione Redox Equilibrium

Loss-of-function parkin mutations cause oxidative stress and degeneration of dopaminergic neurons in the substantia nigra. Several consequences of parkin mutations have been described; to what degree they contribute to selective neurodegeneration remains unclear. Specific factors initiating excessive reactive oxygen species production, inefficient antioxidant capacity, or a combination are elusive. Identifying key oxidative stress contributors could inform targeted therapy. The absence of Drosophila parkin causes selective degeneration of a dopaminergic neuron cluster that is functionally homologous to the substantia nigra. By comparing observations in these to similar non-degenerating neurons, we may begin to understand mechanisms by which parkin loss of function causes selective degeneration. Using mitochondrially targeted redox-sensitive GFP2 fused with redox enzymes, we observed a sustained increased mitochondrial hydrogen peroxide levels in vulnerable dopaminergic neurons of parkin-null flies. Only transient increases in hydrogen peroxide were observed in similar but non-degenerating neurons. Glutathione redox equilibrium is preferentially dysregulated in vulnerable neuron mitochondria. To shed light on whether dysregulated glutathione redox equilibrium primarily contributes to oxidative stress, we supplemented food with folic acid, which can increase cysteine and glutathione levels. Folic acid improved survival, climbing, and transiently decreased hydrogen peroxide and glutathione redox equilibrium but did not mitigate whole-brain oxidative stress.

Alzheimer Disease

PURPOSE OF REVIEW

Alzheimer disease (AD) is the most common cause of dementia in adults (mid to late life), highlighting the importance of understanding the risk factors, clinical manifestations, and recent developments in diagnostic testing and therapeutics.

RECENT FINDINGS

Advances in fluid (CSF and blood-based) and imaging biomarkers are allowing for a more precise and earlier diagnosis of AD (relative to non-AD dementias) across the disease spectrum and in patients with atypical clinical features. Specifically, tau- and amyloid-related AD pathologic changes can now be measured by CSF, plasma, and positron emission tomography (PET) with good precision. Additionally, a better understanding of risk factors for AD has highlighted the need for clinicians to address comorbidities to maximize prevention of cognitive decline in those at risk or to slow decline in patients who are symptomatic. Recent clinical trials of amyloid-lowering drugs have provided not only some optimism that amyloid reduction or prevention may be beneficial but also a recognition that addressing additional targets will be necessary for significant disease modification.

SUMMARY

Recent developments in fluid and imaging biomarkers have led to the improved understanding of AD as a chronic condition with a protracted presymptomatic phase followed by the clinical stage traditionally recognized by neurologists. As clinical trials of potential disease-modifying therapies continue, important developments in the understanding of the disease will improve clinical care now and lead to more effective therapies in the near future.

Folic acid and sodium folate salts: Thermal behavior and spectroscopic (IR, Raman, and solid-state 13C NMR) characterization

Folic acid (FA; vitamin B9) and its associated sodium salts, strongly relevant for many scientific and technological applications - from nutrition to pharmacology and nanomedicine, suffer from a lack of characterization combining experimental and theoretical. In this work, a spectroscopic investigation of FA and its synthesized sodium salts in the form of dianion (Na₂HFol) or trianion (Na₃Fol) was scrutinized in their solid state. The spectroscopic (infrared, Raman, and solid state ¹³C-nuclear magnetic resonance) data interpretation was supported by theoretical calculations using the Density Functional Theory (DFT). Additionally, the compounds were characterized by UV-VIS diffuse-reflectance spectroscopy, combined thermal analysis (TG/DTG-DSC) coupled to mass spectrometry, and X-ray diffractometry. The main signatures of each species were identified, as well as the influence of the protonation level on their physicochemical properties. These distinct properties for the three compounds are mainly based on signals assigned to glutamic acid (glutamate) and pterin (neutral or anionic) moieties. This work should help developing new products based on FA or its anionic forms, such as theragnostic/drug delivery systems, supramolecular structures, nanocarbons, or metal complexes.

Metabolic Basis of Cognitive Improvement Associated With Active B Vitamin Supplementation in Cognitively Impaired Elderly Subjects – A Metabolomics Study

Intervention studies with active B vitamin supplementation in cognitively impaired individuals have yielded varying results in randomized controlled trials. In addition, a negative interaction of active B vitamin supplementation with aspirin usage on cognitive outcome was noted, but the molecular basis of the interaction has largely remained unknown. To investigate the metabolic basis of cognitive improvement brought about by active B vitamin supplementation, we conducted an extensive metabolomics analysis covering 302 identified metabolites on the baseline and 24-month serum samples from a cohort of 137 subjects randomly assigned to active supplementation or placebo. Pathway analysis uncovered enhanced gluconeogenesis and War-burg effects underlying cognitive improvement in non-aspirin users supplemented with active B vitamins. In addition, metabolomics revealed that aspirin usage may interact with B vitamin supplementation by altering gut microbial metabolism, particularly in terms of propionate production. Lastly, our omics data suggest that varying capacities to assimilate B vitamins at baseline, possibly mediated by differences in gut microbial composition, may underlie variations in inter-individual responses to active B vitamin supplementation.

Evaluation of the Effects of Folic Acid Combined with Atorvastatin on the Poststroke Cognitive Impairment by Low-Rank Matrix Denoising Algorithm-Based MRI Imaging

This research aimed to study the optimization effects of the low-rank matrix denoising (LRMD) algorithm based on the Gaussian mixture model (GMM) on MRI images of stroke patients, aiming to evaluate the effects of atorvastatin combined with folic acid on poststroke cognitive impairment (PSCI) in patients with ischemic stroke. First, the GMM-based low-rank matrix denoising (LRMD) algorithm was constructed and applied to process MRI images of 64 patients with ischemic stroke. Then, the MRI images before and after processing were compared for the denoising degree and quality. An image with 5% noise was not as clear as an MRI image with 1% noise, and the effects of atorvastatin combined with folic acid on PSCI in patients with ischemic stroke were discussed. It was found that the denoising degree of MRI images processed by the GMM-based LRMD algorithm was significantly improved, the image quality was significantly enhanced (P < 0.05), and the diagnosis accuracy and efficiency of stroke patients were heightened. Atorvastatin combined with folic acid reduce the homocysteine (HCY) and total cholesterol (TC) levels, as well as Montreal Cognitive Scale (MOCA) scores of PSCI patients (P < 0.05). In conclusion, the MRI images processed by the LRMD algorithm have good quality. Folic acid combined with atorvastatin can effectively reduce HCY and TC levels, thereby alleviating PSCI of stroke patients.

Plasma folate levels in relation to cognitive impairment: a community-based cohort of older adults in China

PURPOSE

Lower plasma level of folate has been associated with an increased risk of age-related cognitive impairment. However, studies that examined this relation have yielded mixed results. We aimed to examine the prospective association of plasma folate level with risk of cognitive impairment in a community-based prospective cohort of older adults in China.

METHODS

This study included 615 participants (mean age: 76.3 years) without baseline cognitive impairment from the Rugao Longevity and Ageing Study (RuLAS). We used logistic regression to examine the prospective association between baseline plasma folate and risk of cognitive impairment in the next two years. Fasting blood samples were collected and assayed for plasma folate level at baseline. Cognitive impairment was defined as Hasegawa Dementia Scale (HDS) score ≤ 21.5 points.

RESULTS

During two years' follow-up, 20.7% of the participants developed cognitive impairment. After controlled for age, gender, and plasma homocysteine, a higher level of plasma folate was associated with lower odds of cognitive impairment. The corresponding odds ratio (OR) with 95% confidence interval was 0.41 (0.19-0.89) comparing participants at extreme quintiles of plasma folate (median level 17.2 vs. 6.3 nmol/L). The associations were similar after further adjustment for major demographic and lifestyle factors (OR = 0.42, 0.18-0.98). Moreover, the inverse association was particularly stronger among males (OR = 0.12, 0.03-0.52) but was non-significant among females.

CONCLUSION

Our findings support a potential beneficial role of higher plasma folate levels in cognitive function in older Chinese adults, particularly among males. Future studies with larger sample size and longer follow-up are warranted to confirm these findings and to identify the optimal plasma folate level for cognitive function.

Baseline folic acid status affects the effectiveness of folic acid supplements in cognitively relevant outcomes in older adults: a systematic review

BACKGROUND

Folic acid was investigated for decreased concentrations of the same type of cysteine (Hcy), which is considered a risk factor for Alzheimer's disease. However, the conclusions are inconsistent, while supplementing elders with different folic acid states.

METHOD

The PubMed, Science Network and EMBASE databases were searched for randomized controlled trials published over the past decade; The 11/485 study was included on the basis of pre-defined criteria. Cognitive-related results, including cognitive function and brain atrophy, were measured using cognitive scales and magnetic resonance imaging.

RESULTS

Significant cognitive benefits were reported in individuals with incomplete folic acid (n s 4); However, individuals with sufficient folic acid (n s 2) do not benefit from supplements, evaluated by the cognitive scale. On the other hand, a significant positive association was established in the participants of plasma Hcy, but the folic acid state was sufficient (n s 2). One study reported that folic acid supplements did not provide any benefit, but folic acid status data were missing. In addition, folic acid supplementation also improves brain atrophy (n s 2).

CONCLUSION

Baseline folic acid status may be a potential factor affecting the results of cognitive function folic acid supplementation in older adults. Older people with insufficient folic acid will benefit from folic acid supplementation.

Vitamin Supplementation and Dementia: A Systematic Review

BACKGROUND

Dementia is a syndrome characterized by progressive cognitive impairment that interferes with independent function in daily activities. Symptoms of dementia depend on its cause and vary greatly between individuals. There is extensive evidence supporting a relationship between diet and cognitive functions. This systematic review studies the efficacy of using vitamin supplements in the diet as a solution to nutritional deficiencies and the prevention of dementia and mild cognitive impairment.

METHODS

An intensive search of different databases (PubMed, Web of Science, and Cochrane CENTRAL) was performed. Articles that were published between 2011 and November 2021 were retrieved using the mentioned search strategy. This systematic review has been conducted according to the PRISMA statement.

RESULTS

Folic acid supplementation proved to have better outcomes on cognitive tests than their respective control groups. The combined supplementation of folic acid and vitamin B12 showed some discrepancies between studies. Thiamine as supplementation did not only prove to have a positive impact on cognitive performance when given alone but also when given in combination with folic acid. Regarding vitamin D supplementation, the results observed were not so encouraging. A concomitant supplementation of low-dose vitamin E and vitamin C was also not associated with an improvement of cognitive function.

CONCLUSIONS

The findings of this systematic review suggest that supplementation of B Complex vitamins, especially folic acid, may have a positive effect on delaying and preventing the risk of cognitive decline. Ascorbic acid and a high dose of vitamin E, when given separately, also showed positive effects on cognitive performance, but there is not sufficient evidence to support their use. The results of vitamin D supplementation trials are not conclusive in assessing the potential benefits that vitamin D might have on cognition.

Combined Effect of Inflammation and Hyperglycemia on Mild Cognitive Impairment and Associated Dietary Patterns in an Older Taiwanese Population

Background

Previous studies have demonstrated that C-reactive protein (CRP) and glycated hemoglobin (HbA1c) levels are independently associated with neurodegenerative diseases, which can be improved by altering dietary patterns. This study investigates the combined effect of CRP and HbA1c, as well as the influence of dietary patterns, on the risk of dementia.

Methods

A cross-sectional study was conducted with 536 participants aged ≥65 years who were recruited from the Nutrition and Health Survey in Taiwan between 2014 and 2016. The high levels of inflammation and glycation were defined as a CRP level of &gt;0.21 mg/dl and a HbA1c level of ≥6.50%, respectively. Mild cognitive impairment (MCI) was evaluated using the Mini-Mental State Examination (MMSE) score. The dietary patterns associated with CRP and HbA1c levels were assessed using the reduced rank regression (RRR). Multivariate logistic regression analysis of both complete and imputed datasets was performed.

Results

Participants with high levels of both CRP and HbA1c were associated with the highest odds ratio (OR) of MCI (adjusted OR [aOR] = 3.52; 95% CI = 3.48, 3.56; p &lt; 0.001), followed by a high level of only HbA1c (aOR = 1.73; p &lt; 0.001) and a high level of CRP (aOR = 1.49; p &lt; 0.001). Using the reduced rank regression, an inverse relationship between higher consumption nuts and seeds and lower levels of CRP and HbA1c was found (both factors loading &lt; −0.2). Concerning the combined effect of tertiles among the factor 1 and factor 2 analyzed by dietary patterns, group 1 with both T3 (high tertiles) was associated with the greatest OR of MCI (aOR = 4.38; 95% CI = 4.34, 4.42; p &lt; 0.001) using multiple imputation.

Conclusions

The combined effect of high levels of inflammation and hyperglycemia was associated with an increased likelihood of MCI. Moreover, dietary patterns positively related to inflammation and hyperglycemia were associated with MCI, while eating nuts and seeds promoted better cognition.

One-Carbon Metabolism: Pulling the Strings behind Aging and Neurodegeneration

One-carbon metabolism (OCM) is a network of biochemical reactions delivering one-carbon units to various biosynthetic pathways. The folate cycle and methionine cycle are the two key modules of this network that regulate purine and thymidine synthesis, amino acid homeostasis, and epigenetic mechanisms. Intersection with the transsulfuration pathway supports glutathione production and regulation of the cellular redox state. Dietary intake of micronutrients, such as folates and amino acids, directly contributes to OCM, thereby adapting the cellular metabolic state to environmental inputs. The contribution of OCM to cellular proliferation during development and in adult proliferative tissues is well established. Nevertheless, accumulating evidence reveals the pivotal role of OCM in cellular homeostasis of non-proliferative tissues and in coordination of signaling cascades that regulate energy homeostasis and longevity. In this review, we summarize the current knowledge on OCM and related pathways and discuss how this metabolic network may impact longevity and neurodegeneration across species.

The Effects of Folic Acid Supplementation on Pro-inflammatory Mediators: a Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

PURPOSE

Despite extensive research, findings regarding the effects of folic acid supplementation on inflammatory mediators have been controversial and inconclusive. This study therefore aimed to summarize the findings of all available clinical trials regarding the effects of folic acid supplementation on inflammatory biomarkers in adults.

METHODS

A systematic search was conducted of PubMed/MEDLINE, Scopus, Web of Science, EMBASE, and Google Scholar until April 2020. All randomized controlled trials that examined the influence of folic acid supplementation on C-reactive protein, interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) were included. Pooled effect sizes were calculated based on the random effects model, and dose-response analysis was modeled by using a fractional polynomial model.

FINDINGS

In total, 18 randomized controlled trials involving 2286 participants were analyzed. Folic acid supplementation significantly reduced serum levels of C-reactive protein (mean difference [MD], -0.21 mg/L; 95% CI, -0.41 to -0.01; n = 16), TNF-α (MD, -14.88 pg/mL; 95% CI, -23.68 to -6.09; n = 10), and IL-6 (MD, -0.93 pg/mL; 95% CI, -1.72 to -0.14; n = 11). Subgroup analyses suggested a significant reduction at doses ≤5 mg/d and studies longer than 12 weeks in duration. A significant nonlinear association was also found between folic acid dosage (P_nonlinearity <0.001) and duration of administration (P_nonlinearity <0.001) with serum TNF-α levels.

IMPLICATIONS

This meta-analysis indicates the beneficial effects of folic acid supplementation on pro-inflammatory cytokines. Further studies with a longer duration of administration, higher doses, and larger sample sizes should be performed exclusively on patients with chronic inflammatory disorders to elucidate the favorable role of folate intake on inflammatory biomarkers. International Prospective Register of Systematic Reviews identifier: CRD42021249947.

Folic acid attenuated learning and memory impairment via inhibition of oxidative damage and acetylcholinesterase activity in hypothyroid rats

Hypothyroidism has been reported to be associated with cognitive decline. Considering the role of folic acid (FA) in cognitive performance, the present study was designed to investigate the effects of FA on hypothyroidism-induced cognitive impairment, oxidative damage, and alterations in acetylcholinesterase (AChE) activity in rat model of propylthiouracil (PTU)-induced hypothyroidism. In this study, PTU (0.05% in drinking water) and FA (5, 10, and 15 mg/kg, oral gavage) were administered for the rats during 7 weeks. Then, behavioral performance was tested using Morris water maze (MWM) and passive avoidance (PA) tasks. Finally, oxidative stress indicators and AChE activity were assayed in the brain tissues. The impairing effect of hypothyroidism on cognitive performance was markedly alleviated by FA especially at higher doses. In the MWM test, FA reduced escape latency and travelled distance, compared to the non-treated hypothyroid group. In the PA test, latency to enter dark chamber was significantly enhanced by FA compared to the non-treated hypothyroid group (p < 0.05-p < 0.001). Besides, FA attenuated AChE activity and malondialdehyde level but it increased activity of superoxide dismutase enzyme and total thiol content (p < 0.05-p < 0.001). In conclusion, our findings revealed that FA could improve learning and memory ability in hypothyroid rats. The observed protective effects may have been mediated through regulation of oxidative stress and AChE activity.

Folic Acid Treatment for Patients with Vascular Cognitive Impairment: A Systematic Review and Meta-Analysis

BACKGROUND

As the life expectancy of elderly people has drastically increased, the incidence of cardiovascular and cerebrovascular diseases in this population has proportionally grown. Vascular cognitive impairment (VCI) refers to all forms of cognitive disorder associated with cerebrovascular disease. Homocysteine has recently been recognized as a contributor to the pathomechanisms involved in cognitive impairment. B vitamins, such as folic acid, are known to be effective in lowering homocysteine levels.

AIM OF THE STUDY

To evaluate the efficacy of folic acid in patients with VCI.

METHODS

We conducted a systematic review and meta-analysis of research on folic acid treatments for VCI. Only randomized controlled trials studies that compared the efficacy of folic acid to placebo or other interventions were considered, irrespective of publication status, year of publication, and languages. Two independent reviewers searched the Medline via Ovid, EMBASE and Cochrane Central Register of Controlled Trials (Central) journal databases up to July 2021 and independently appraised the included studies. We used mean difference outcome with 95% confidence intervals (CI) to calculate the change of Mini-Mental State Examination (MMSE), cognitive function domain, and concentration of homocysteine.

RESULTS

We found three studies comparing folic acid with placebo and one study comparing folic acid with other interventions. There is only slight evidence that the MMSE score in patients who received Folic Acid increased 0.3 point higher compared to the placebo group after 24 months (95% CI:-0.12-0.37; p=0.31). There is very strong evidence that the concentration of Homocysteine in the Folic Acid group became 6.16 μmol/L lower compared to the placebo group after 6 months (95% CI:2.32-8.21 lower; p<0.001).

CONCLUSIONS

Our review shows the effectiveness of folic acid in lowering plasma homocysteine concentration after 6 months period compared to placebo. However, this effect is not accompanied by improvement in cognitive function.

The dihydrofolate reductase 19-bp deletion modifies the beneficial effect of B-vitamin therapy in mild cognitive impairment: Pooled study of two randomized placebo-controlled trials

BACKGROUND

Higher serum homocysteine is associated with cognitive decline in older people. But homocysteine-lowering trials including folic acid (FA) show inconsistent results on cognitive decline. The reduction of FA to dihydrofolate by dihydrofolate reductase (DHFR) is slow in humans.

OBJECTIVE

We examined the effects of the DHFR 19-bp deletion/insertion (del/ins) polymorphism on FA-containing treatment on cognitive decline and brain atrophy in older people with mild cognitive impairment (MCI).

METHODS

This study used pooled data from two randomized B-vitamin trials on 545 MCI subjects who received either FA-containing B vitamins or placebo for 24 months. Subjects were typed for the DHFR genotype. Primary outcome was the Clinical Dementia Rating scale-global score (CDR-global). Secondary outcomes were CDR-sum of boxes score (CDR-SOB), memory and executive Z-scores, and whole brain atrophy rate by serial MRI.

RESULTS

The proportion of subjects with del/del, del/ins and ins/ins genotype were 29.5%, 44.3% and 26.1%, respectively. DHFR genotypes modified the effects of B vitamins on CDR-global, CDR-SOB and executive function Z-score (Pinteraction = 0.017, 0.014 and 0.052, respectively), with significant benefits being observed only in those with ins/ins genotype (Beta = -1.367, -0.614 and 0.315, P = 0.004, 0.014 and 0.012, respectively). The interaction was not significant for memory Z-score and whole brain atrophy rate. Notably, the supplements only slowed brain atrophy in members of the 'ins/ins' group who were not using aspirin.

CONCLUSIONS

Our data indicate that the beneficial effects of B vitamins including FA on cognitive function are only apparent in those with ins/ins genotype, i.e. relatively better preserved DHFR activity.

CRIF1 Deficiency Increased Homocysteine Production by Disrupting Dihydrofolate Reductase Expression in Vascular Endothelial Cells

Elevated plasma homocysteine levels can induce vascular endothelial dysfunction; however, the mechanisms regulating homocysteine metabolism in impaired endothelial cells are currently unclear. In this study, we deleted the essential mitoribosomal gene CR6 interacting factor 1 (CRIF1) in human umbilical vein endothelial cells (HUVECs) and mice to induce endothelial cell dysfunction; then, we monitored homocysteine accumulation. We found that CRIF1 downregulation caused significant increases in intracellular and plasma concentrations of homocysteine, which were associated with decreased levels of folate cycle intermediates such as 5-methyltetrahydrofolate (MTHF) and tetrahydrofolate (THF). Moreover, dihydrofolate reductase (DHFR), a key enzyme in folate-mediated metabolism, exhibited impaired activity and decreased protein expression in CRIF1 knockdown endothelial cells. Supplementation with folic acid did not restore DHFR expression levels or MTHF and homocysteine concentrations in endothelial cells with a CRIF1 deletion or DHFR knockdown. However, the overexpression of DHFR in CRIF1 knockdown endothelial cells resulted in decreased accumulation of homocysteine. Taken together, our findings suggest that CRIF1-deleted endothelial cells accumulated more homocysteine, compared with control cells; this was primarily mediated by the disruption of DHFR expression.

B Vitamins Supplementation Can Improve Cognitive Functions and May Relate to the Enhancement of Transketolase Activity in A Rat Model of Cognitive Impairment Associated with High-fat Diets

OBJECTIVE

To determine whether B vitamin treatment was sufficient to reduce cognitive impairment associated with high-fat diets in rats and to modulate transketolase (TK) expression and activity.

METHODS

To test this, we separated 50 rats into five groups that were either fed a standard chow diet (controls) or a high-fat diet (experimental groups H0, H1, H2, and H3). H0 group animals received no additional dietary supplementation, while H1 group animals were administered 100 mg/kg body weight (BW) thiamine, 100 mg/kg BW riboflavin, and 250 mg/kg BW niacin each day, and group H2 animals received daily doses of 100 mg/kg BW pyridoxine, 100 mg/kg BW cobalamin, and 5 mg/kg BW folate. Animals in the H3 group received the B vitamin regimens administered to both H1 and H2 each day.

RESULTS

Over time, group H0 exhibited greater increases in BW and fat mass relative to other groups. When spatial and memory capabilities in these animals were evaluated via conditioned taste aversion (CTA) and Morris Water Maze (MWM), we found B vitamin treatment was associated with significant improvements relative to untreated H0 controls. Similarly, B vitamin supplementation was associated with elevated TK expression in erythrocytes and hypothalamus of treated animals relative to those in H0 (P<0.05).

CONCLUSION

Together, these findings suggest B vitamin can modulate hypothalamic TK activity to reduce the severity of cognitive deficits in a rat model of obesity. As such, B vitamin supplementation may be a beneficial method for reducing cognitive dysfunction in clinical settings associated with high-fat diets.

Homocysteine - from disease biomarker to disease prevention

We have reviewed the literature and have identified more than 100 diseases or conditions that are associated with raised concentrations of plasma total homocysteine. The commonest associations are with cardiovascular diseases and diseases of the central nervous system, but a large number of developmental and age-related conditions are also associated. Few other disease biomarkers have so many associations. The clinical importance of these associations becomes especially relevant if lowering plasma total homocysteine by B vitamin treatment can prevent disease and so improve health. Five diseases can at least in part be prevented by lowering total homocysteine: neural tube defects, impaired childhood cognition, macular degeneration, primary stroke, and cognitive impairment in the elderly. We conclude from our review that total homocysteine values in adults of 10 μmol/L or below are probably safe, but that values of 11 μmol/L or above may justify intervention. Homocysteine is more than a disease biomarker: it is a guide for the prevention of disease.

Mindfulness Awareness Practice (MAP) to Prevent Dementia in Older Adults with Mild Cognitive Impairment: Protocol of a Randomized Controlled Trial and Implementation Outcomes

BACKGROUND

With an aging population, developing non-pharmacological interventions (NPIs) to delay dementia has become critical. Apart from cognitive decline, dementia is associated with multiple pathophysiology, including increased oxidative stress, dysregulated gene expressions, cytokine, neurotrophin, and stress markers, telomere shortening, and deteriorations in brain connectivity. Although mindfulness practices have been proposed to ameliorate these biological changes, no empirical studies were conducted. We thus aimed to investigate the effects of mindfulness awareness practice (MAP) to prevent cognitive decline and improve peripheral biomarkers in community-dwelling older adults diagnosed with mild cognitive impairment (MCI).

METHODS/DESIGN

This was a single-blinded and parallel-group randomized controlled trial with two arms (intervention and active control arms), conducted over nine months. A total of 60 consenting community-dwelling older adults diagnosed with MCI were planned to be randomized in a 1:1 ratio to either the MAP or the Health Education Program (HEP). Interventions were performed weekly for the initial 12 weeks, and monthly for the subsequent six months. Outcome measures were assessed at baseline, 3-month, and 9-month post-intervention by blinded assessors. Primary outcomes were neurocognitive tests, comprehensive peripheral biomarkers, and brain imaging scans. Secondary outcomes included basic health screening measures, affective symptoms, and measures of physical functions. Linear-mixed models were used to examine the effects of MAP on these outcome measures.

SIGNIFICANCE

This is the first randomized controlled trial to systematically investigate the effects of a mindfulness intervention in improving cognitive functions and various biomarkers in community-dwelling older adults diagnosed with MCI. Our findings have the potential to inform mindfulness intervention as a novel approach to delay dementia.

Effects of Supplementation with Folic Acid and Its Combinations with Other Nutrients on Cognitive Impairment and Alzheimer's Disease: A Narrative Review

Cognitive impairment and Alzheimer's Disease, among other cognitive dysfunctions, has been recognized as a major public health problem. Folic acid is a well-known essential nutrient whose deficiency has been linked to neurocognitive dysfunctions, owing to hyperhomocysteinemia, an independent risk factor for cardio- and cerebrovascular diseases, including cognitive impairment, Alzheimer's Disease, and vascular dementia. However, to date, there is certain controversy about the efficacy of vitamin supplementation in patients with these pathologies. Therefore, we have reviewed the available dietary intervention studies based on folic acid, either alone or in combination with different vitamins or nutrients into the progression of Alzheimer's Disease and Cognitive impairment, highlighting the cognition and biochemical markers employed for the evaluation of the disease progression. Undeniably, the compiled information supports the potential benefits of vitamin supplementation in these pathologies, especially relevant to the aging process and quality of life, although more research is urgently needed to confirm these positive findings.

Effects of chemotherapy for acute lymphoblastic leukemia on cognitive function in animal models of contemporary protocols: A systematic literature review

Survival rates of childhood acute lymphoblastic leukemia (ALL) have improved greatly due to advanced therapies and supportive care. Intrathecal chemotherapy replaced cranial radiation due to radiation-induced neurotoxicity and late-effects. Survivors treated with chemotherapy-only experience neurologic and cognitive problems following cessation of treatment. Very long-term cognitive outcomes remain unclear. Animal models are being generated to assess late-effects of chemotherapy on cognitive function. Although, few address juvenile models of chemotherapy-induced cognitive impairment (CICI) and developing brain, results of this review outline neurocognitive effects of chemotherapy consistent with childhood ALL therapy. Studies demonstrate deficits across cognitive domains including spatial memory, executive function, short-term memory, anxiety and depression. Inflammation, oxidative stress, excitotoxity, and other metabolic disruptions may lead to neurodegeneration associated with cognitive impairment observed in ALL survivors. Interventions directly targeting these mechanisms may prevent and/or promote recovery of cognitive function and improve long-term outcomes. Evidence suggests success of anti-inflammatory and antioxidant treatments in reducing cognitive decline. Animal models provide basis for assessing effects of chemotherapy on neurologic processes to guide future clinical investigations.

Serum Amyloid Beta42 Is Not Eliminated by the Cirrhotic Liver: A Pilot Study

Amyloid-beta (Aβ) deposition in the brain is the main pathological hallmark of Alzheimer disease. Peripheral clearance of Aβ may possibly also lower brain levels. Recent evidence suggested that hepatic clearance of Aβ42 is impaired in liver cirrhosis. To further test this hypothesis, serum Aβ42 was measured by ELISA in portal venous serum (PVS), systemic venous serum (SVS), and hepatic venous serum (HVS) of 20 patients with liver cirrhosis. Mean Aβ42 level was 24.7 ± 20.4 pg/mL in PVS, 21.2 ± 16.7 pg/mL in HVS, and 19.2 ± 11.7 pg/mL in SVS. Similar levels in the three blood compartments suggested that the cirrhotic liver does not clear Aβ42. Aβ42 was neither associated with the model of end-stage liver disease score nor the Child–Pugh score. Patients with abnormal creatinine or bilirubin levels or prolonged prothrombin time did not display higher Aβ42 levels. Patients with massive ascites and patients with large varices had serum Aβ42 levels similar to patients without these complications. Serum Aβ42 was negatively associated with connective tissue growth factor levels (r = −0.580, p = 0.007) and a protective role of Aβ42 in fibrogenesis was already described. Diabetic patients with liver cirrhosis had higher Aβ42 levels (p = 0.069 for PVS, p = 0.047 for HVS and p = 0.181 for SVS), which is in accordance with previous reports. Present analysis showed that the cirrhotic liver does not eliminate Aβ42. Further studies are needed to explore the association of liver cirrhosis, Aβ42 levels, and cognitive dysfunction.

Regulation of the one carbon folate cycle as a shared metabolic signature of longevity

The metabolome represents a complex network of biological events that reflects the physiologic state of the organism in health and disease. Additionally, specific metabolites and metabolic signaling pathways have been shown to modulate animal ageing, but whether there are convergent mechanisms uniting these processes remains elusive. Here, we used high resolution mass spectrometry to obtain the metabolomic profiles of canonical longevity pathways in C. elegans to identify metabolites regulating life span. By leveraging the metabolomic profiles across pathways, we found that one carbon metabolism and the folate cycle are pervasively regulated in common. We observed similar changes in long-lived mouse models of reduced insulin/IGF signaling. Genetic manipulation of pathway enzymes and supplementation with one carbon metabolites in C. elegans reveal that regulation of the folate cycle represents a shared causal mechanism of longevity and proteoprotection. Such interventions impact the methionine cycle, and reveal methionine restriction as an underlying mechanism. This comparative approach reveals key metabolic nodes to enhance healthy ageing.