The efficacy of supplementation with the novel medical food, Souvenaid, in patients with Alzheimer's disease: A systematic review and meta-analysis of randomized clinical trials

The influence of time-restricted eating/feeding on Alzheimer's biomarkers and gut microbiota

OBJECTIVES

Alzheimer's disease (AD) is a progressive neurodegenerative disorder affecting approximately 55 million individuals globally. Diagnosis typically occurs in advanced stages, and there are limited options for reversing symptoms. Preventive strategies are, therefore, crucial. Time Restricted Eating (TRE) or Time Restricted Feeding (TRF) is one such strategy. Here we review recent research on AD and TRE/TRF in addition to AD biomarkers and gut microbiota.

METHODS

A comprehensive review of recent studies was conducted to assess the impact of TRE/TRF on AD-related outcomes. This includes the analysis of how TRE/TRF influences circadian rhythms, beta-amyloid 42 (Aß42), pro-inflammatory cytokines levels, and gut microbiota composition.

RESULTS

TRE/TRF impacts circadian rhythms and can influence cognitive performance as observed in AD. It lowers beta-amyloid 42 deposition in the brain, a key AD biomarker, and reduces pro-ininflammatory cytokines. The gut microbiome has emerged as a modifiable factor in AD treatment. TRE/TRF changes the structure and composition of the gut microbiota, leading to increased diversity and a decrease in harmful bacteria.

DISCUSSION

These findings underscore the potential of TRE/TRF as a preventive strategy for AD. By reducing Aß42 plaques, modulating pro-inflammatory cytokines, and altering gut microbiota composition, TRE/TRF may slow the progression of AD. Further research is needed to confirm these effects and to understand the mechanisms involved. This review highlights TRE/TRF as a promising non-pharmacological intervention in the fight against AD.

ESPEN guideline on nutrition and hydration in dementia - Update 2024

BACKGROUND & AIMS

Dementia is accompanied by a variety of changes that result in an increased risk of malnutrition and low-intake dehydration. This guideline update aims to give evidence-based recommendations for nutritional care of persons with dementia in order to prevent and treat these syndromes.

METHODS

The previous guideline version was reviewed and expanded in accordance with the standard operating procedure for ESPEN guidelines. Based on a systematic search in three databases, strength of evidence of appropriate literature was graded by use of the SIGN system. The original recommendations were reviewed and reformulated, and new recommendations were added, which all then underwent a consensus process.

RESULTS

40 recommendations for nutritional care of older persons with dementia were developed and agreed, seven at institutional level and 33 at individual level. As a prerequisite for good nutritional care, organizations caring for persons with dementia are recommended to employ sufficient qualified staff and offer attractive food and drinks with choice in a functional and appealing environment. Nutritional care should be based on a written care concept with standardized operating procedures. At the individual level, routine screening for malnutrition and dehydration, nutritional assessment and close monitoring are unquestionable. Oral nutrition may be supported by eliminating potential causes of malnutrition and dehydration, and adequate social and nursing support (including assistance, utensils, training and oral care). Oral nutritional supplements are recommended to improve nutritional status but not to correct cognitive impairment or prevent cognitive decline. Routine use of dementia-specific ONS, ketogenic diet, omega-3 fatty acid supplementation and appetite stimulating agents is not recommended. Enteral and parenteral nutrition and hydration are temporary options in patients with mild or moderate dementia, but not in severe dementia or in the terminal phase of life. In all stages of the disease, supporting food and drink intake and maintaining or improving nutrition and hydration status requires an individualized, comprehensive approach. Due to a lack of appropriate studies, most recommendations are good practice points.

CONCLUSION

Nutritional care should be an integral part of dementia management. Numerous interventions are available that should be implemented in daily practice. Future high-quality studies are needed to clarify the evidence.

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.

Fatty acids and beyond: Age and Alzheimer's disease related changes in lipids reveal the neuro-nutraceutical potential of lipids in cognition

Lipids are essential in maintaining brain function, and lipid profiles have been reported to be altered in aged and Alzheimer's disease (AD) brains as compared to healthy mature brains. Both age and AD share common metabolic hallmarks such as increased oxidative stress and perturbed metabolic function, and age remains the most strongly correlated risk factor for AD, a neurodegenerative disease. A major accompanying pathological symptom of these conditions is cognitive impairment, which is linked with changes in lipid metabolism. Thus, nutraceuticals that affect brain lipid metabolism or lipid levels as a whole have the potential to ameliorate cognitive decline. Lipid analyses and lipidomic studies reveal changes in specific lipid types with aging and AD, which can identify potential lipid-based nutraceuticals to restore the brain to a healthy lipid phenotype. The brain lipid profile can be influenced directly with dietary administration of lipids themselves, although because of synergistic effects of nutrients it may be more useful to consider a multi-component diet rather than single nutrient supplementation. Gut microbiota also serve as a source of beneficial lipids, and the value of treatments that manipulate the composition of gut microbiome should not be ignored. Lastly, instead of direct supplementation, compounds that affect pathways involved with lipid metabolism should also be considered as a way of manipulating lipid levels to improve cognition. In this review, we briefly discuss the role of lipids in the brain, the changing lipid profile in AD, current research on lipid-based nutraceuticals and their therapeutic potential to combat cognitive impairment.

Selenium concentrations in elderly people with Alzheimer's disease: a cross-sectional study with control group

OBJECTIVE

To investigate possible differences in plasma and erythrocyte concentrations of selenium among elderly with and without a diagnosis of Alzheimer's disease (AD).

METHODS

Cross-sectional study, performed with an elderly group with Alzheimer's disease, diagnosed by a geriatric doctor, and compared to an elderly group without the disease, equaling gender, education, and age. Atomic absorption spectrophotometry determined plasma and erythrocyte concentrations of total selenium (Set).

RESULTS

The mean age was 74.41±7.1 years in the Alzheimer's disease group and 71.46±5.1 years among the control group. The Alzheimer's disease group presented lower plasma concentrations (mean of 45.29±14.51 µg/dL vs. 55.14±14.01 µg/dL; p=0.004), and erythrocyte Set (median of 56.36 µg/L vs. 76.96 µg/L; p<0.001). The logistic regression model indicated an association between erythrocyte Set concentrations and diagnosis of Alzheimer's disease (p=0.028).

CONCLUSION

Elderly with Alzheimer's disease present lower selenium concentrations in the evaluated organic compartments.

The Impact of Nutrients on Mental Health and Well-Being: Insights From the Literature

A good nutritional status is important for maintaining normal body function and preventing or mitigating the dysfunction induced by internal or external factors. Nutritional deficiencies often result in impaired function, and, conversely, intakes at recommended levels can resume or further enhance body functions. An increasing number of studies are revealing that diet and nutrition are critical not only for physiology and body composition, but also have significant effects on mood and mental well-being. In particular, Western dietary habits have been the object of several research studies focusing on the relationship between nutrition and mental health. This review aims to summarize the current knowledge about the relationship between the intake of specific micro- and macronutrients, including eicosapentaenoic acid, docosahexaenoic acid, alpha-tocopherol, magnesium and folic acid, and mental health, with particular reference to their beneficial effect on stress, sleep disorders, anxiety, mild cognitive impairment, as well as on neuropsychiatric disorders, all significantly affecting the quality of life of an increasing number of people. Overall data support a positive role for the nutrients mentioned above in the preservation of normal brain function and mental well-being, also through the control of neuroinflammation, and encourage their integration in a well-balanced and varied diet, accompanied by a healthy lifestyle. This strategy is of particular importance when considering the global human aging and that the brain suffers significantly from the life-long impact of stress factors.

Souvenaid for Alzheimer's disease

BACKGROUND

Souvenaid is a dietary supplement with a patented composition (Fortasyn Connect™)which is intended to be used by people with Alzheimer's disease (AD). It has been designed to support the formation and function of synapses in the brain, which are thought to be strongly correlated with cognitive function. If effective, it might improve symptoms of Alzheimer's disease and also prevent the progression from prodromal Alzheimer's disease to dementia. We sought in this review to examine the evidence for this proposition.

OBJECTIVES

To assess the effects of Souvenaid on incidence of dementia, cognition, functional performance, and safety in people with Alzheimer's disease.

SEARCH METHODS

We searched ALOIS, i.e. the specialised register of the Cochrane Dementia and Cognitive Improvement Group, MEDLINE (Ovid SP), Embase (Ovid SP), PsycINFO (Ovid SP), Web of Science (ISI Web of Science), Cinahl (EBSCOhost), Lilacs (BIREME), and clinical trials registries up to 24 June 2020. We also reviewed citations of reference lists of landmark papers, reviews, and included studies for additional studies and assessed their suitability for inclusion in the review.

SELECTION CRITERIA

We included randomised, placebo-controlled trials which evaluated Souvenaid in people diagnosed with mild cognitive impairment (MCI) due to AD (also termed prodromal AD) or with dementia due to AD, and with a treatment duration of at least 16 weeks.

DATA COLLECTION AND ANALYSIS

Our primary outcome measures were incidence of dementia, global and specific cognitive function, functional performance, combined cognitive-functional outcomes and adverse events. We selected studies, extracted data, assessed the quality of trials and intended to conduct meta-analyses according to the Cochrane Handbook for Systematic Reviews of Interventions. We rated the quality of the evidence using the GRADE approach. We present all outcomes grouped by stage of AD.

MAIN RESULTS

We included three randomised, placebo-controlled trials investigating Souvenaid in 1097 community-dwelling participants with Alzheimer's disease. One study each included participants with prodromal AD, mild AD dementia and mild-to-moderate AD dementia. We rated the risks of bias of all trials as low. One study (in prodromal AD) was funded by European grants. The other two studies were funded by the manufacturer of Souvenaid. One trial investigated the incidence of dementia in people with prodromal AD at baseline, and found little to no difference between the Souvenaid group and the placebo group after 24 months (RR 1.09, 95% CI 0.82 to 1.43; 1 trial, 311 participants; moderate quality of evidence). In prodromal AD, and in mild and mild-to-moderate Alzheimer's disease dementia, Souvenaid probably results in little or no difference in global or specific cognitive functions (moderate quality of evidence). Everyday function, or the ability to perform activities of daily living, were measured in mild and mild-to-moderate AD dementia. Neither study found evidence of a difference between the groups after 24 weeks of treatment (moderate quality of evidence). Two studies investigated combined cognitive-functional outcomes with the Clinical Dementia Rating Sum of Boxes and observed conflicting results. Souvenaid probably results in slight improvement, which is below estimates of meaningful change, in participants with prodromal Alzheimer's disease after 24 months (moderate quality of evidence), but probably has little to no effect in mild-to-moderate Alzheimer's disease dementia after 24 weeks (moderate quality of evidence). Adverse effects observed were low in all trials, and the available data were insufficient to determine any connection with Souvenaid.

AUTHORS' CONCLUSIONS

Two years of treatment with Souvenaid probably does not reduce the risk of progression to dementia in people with prodromal AD. There is no convincing evidence that Souvenaid affects other outcomes important to people with AD in the prodromal stage or mild-to-moderate stages of dementia. Conflicting evidence on combined cognitive-functional outcomes in prodromal AD and mild AD dementia warrants further investigation. Adverse effects of Souvenaid seem to be uncommon, but the evidence synthesised in this review does not permit us to make a definitive statement on the long-term tolerability of Souvenaid. The effects of Souvenaid in more severe AD dementia or in people with AD at risk of nutritional deficiencies remain unclear.

APOE Genotype Differentially Modulates Plasma Lipids in Healthy Older Individuals, with Relevance to Brain Health

Apolipoprotein E (APOE) genotype is an established genetic risk factor for sporadic Alzheimer's disease (AD) but the extent to which APOE genotype influences the plasma lipidome is unknown, even though lipids are potential diagnostic or prognostic biomarkers for AD. We quantified plasma lipids using untargeted liquid chromatography coupled mass spectrometry in a total of 152 non-demented participants aged 65-100 years carrying at least one ɛ2 or ɛ4 allele (ɛ2/ɛ2 or ɛ2/ɛ3, n = 38: ɛ4/ɛ3 or ɛ4/ɛ4, n = 38), who were roughly matched to an ɛ3/ɛ3 control by age, sex, and lipid-lowering medication (n = 76). Low density lipoprotein cholesterol levels were genotype dependent (ɛ4/ɛ4> ɛ4/ɛ3> ɛ3/ɛ3> ɛ2/ɛ3> ɛ2/ɛ2). The greatest variation in lipids was related to the ɛ2 isoform, where various lysophosphatidylcholines and all phosphatidylethanolamine (PE) subclasses were elevated relative to ɛ3/ɛ3 and ɛ4 carriers. APOEɛ4 carriers had reduced phosphatidylinositol relative to ɛ3/ɛ3 and ɛ2 carriers. Logistic regression revealed that ɛ2 carriers were at least 4 times higher odds of being in the highest tertile of PE lipid level relative to ɛ3/ɛ3. The elevation in PE and other phospholipids in ɛ2 carriers may indicate the protective effect of ɛ2 is linked to these phospholipids. Additionally, high baseline PE in cognitively normal participants predicted protection against cognitive decline six years later. Our data suggest substantial modulation of plasma lipids by APOE genotype and therefore indicates possible lipid targets and pathomechanisms involved in AD risk.

Dietary interventions in mild cognitive impairment and dementia

Dietary intervention is an enticing approach in the fight against cognitive impairment. Nutritional supplements and dietetic counseling are relatively easy and benign interventions, but research has not yet yielded irrefutable evidence as to their clinical utility. Heterogeneity in the results of available clinical studies, as well as methodological and practical issues, does not allow replication and generalization of findings. The paper at hand reviews only randomized clinical trials of single nutrients, multi-nutrient formulations and dietary counseling in mild cognitive impairment and dementia of the Alzheimer's type focusing on both cognitive and functional outcomes. Thus far, folate, vitamin E, Ω-3 fatty acids, and certain multi-nutrient formulations have shown some preliminary promising results; larger, well-designed trials are needed to confirm these findings before nutritional elements can be incorporated in recommended clinical guidelines.

Souvenaid in the management of mild cognitive impairment: an expert consensus opinion

Background

Mild cognitive impairment (MCI) among an aging global population is a growing challenge for healthcare providers and payers. In many cases, MCI is an ominous portent for dementia. Early and accurate diagnosis of MCI provides a window of opportunity to improve the outcomes using a personalized care plan including lifestyle modifications to reduce the impact of modifiable risk factors (for example, blood pressure control and increased physical activity), cognitive training, dietary advice, and nutritional support. Souvenaid is a once-daily drink containing a mixture of precursors and cofactors (long-chain omega-3 fatty acids, uridine, choline, B vitamins, vitamin C, vitamin E, and selenium), which was developed to support the formation and function of neuronal membranes and synapses. Healthcare providers, patients, and carers require expert advice about the use of Souvenaid.

Methods

An international panel of experts was convened to review the evidence and to make recommendations about the diagnosis and management of MCI, identification of candidates for Souvenaid, and use of Souvenaid in real-world practice. This article provides a summary of the expert opinions and makes recommendations for clinical practice and future research.

Summary of opinion

Early diagnosis of MCI requires the use of suitable neuropsychological tests combined with a careful clinical history. A multimodal approach is recommended; dietary and nutritional interventions should be considered alongside individualized lifestyle modifications. Although single-agent nutritional supplements have failed to produce cognitive benefits for patients with MCI, a broader nutritional approach warrants consideration. Evidence from randomized controlled trials suggests that Souvenaid should be considered as an option for some patients with early Alzheimer’s disease (AD), including those with MCI due to AD (prodromal AD).

Conclusion

Early and accurate diagnosis of MCI provides a window of opportunity to improve the outcomes using a multimodal management approach including lifestyle risk factor modification and consideration of the multinutrient Souvenaid.

Electronic supplementary material

The online version of this article (10.1186/s13195-019-0528-6) contains supplementary material, which is available to authorized users.

Brain Selenium in Alzheimer's Disease (BRAIN SEAD Study): a Systematic Review and Meta-Analysis

Oxidative stress has been found to be implicated in the development of Alzheimer's disease (AD). In this meta-analytic review, we compared tissue levels between AD and non-AD brains of selenium, an important biological trace element well known for its vital role in the brain function. We included 14 studies with 40 observations on selenium concentrations in AD and control brains. The effect size as standardized mean difference (SMD) was generated using review manager 5.3. Random-effects meta-analysis indicated a decrease (SMD = - 0.42) in brain tissue selenium levels in AD as compared to non-AD controls. The subgroup meta-analysis demonstrated that the selenium levels were decreased in the temporal, hippocampal, and cortex regions in AD. The funnel plot with Egger's (p = 0.88) and Begg's tests (p = 0.24) detected no significant publication bias. The results of sensitivity analysis indicated that no single study/observation had significantly influenced the overall outcome. This meta-analysis provides consolidated evidence for a significant decrease of selenium status in AD brains compared to controls. In line with the evidence supporting selenium's antioxidant role and the involvement of oxidative stress in AD development, this meta-analysis supports new therapeutic strategies aimed at brain tissue selenium homeostasis in AD.

Nutritional interventions and cognitive-related outcomes in patients with late-life cognitive disorders: A systematic review

There have been a large number of observational studies on the impact of nutrition on neuroprotection, however, there was a lack of evidence from randomized clinical trials (RCTs). In the present systematic review, from the 32 included RCTs published in the last four years (2014-2017) in patients aged 60 years and older with different late-life cognitive disorders, nutritional intervention through medical food/nutraceutical supplementation and multidomain approach improved magnetic resonance imaging findings and other cognitive-related biomarkers, but without clear effect on cognition in mild Alzheimer's disease (AD) and mild cognitive impairment (MCI). Antioxidant-rich foods (nuts, grapes, cherries) and fatty acid supplementation, mainly n-3 polyunsaturated fatty acids (PUFA), improved specific cognitive domains and cognitive-related outcomes in MCI, mild-to-moderate dementia, and AD. Antioxidant vitamin and trace element supplementations improved only cognitive-related outcomes and biomarkers, high-dose B vitamin supplementation in AD and MCI patients improved cognitive outcomes in the subjects with a high baseline plasma n-3 PUFA, while folic acid supplementation had positive impact on specific cognitive domains in those with high homocysteine.

Comparison of the effects of selenomethionine and selenium-enriched yeast in the triple-transgenic mouse model of Alzheimer's disease

Alzheimer's disease (AD) is a complex, multifactorial neurodegenerative disease that exhibits multiple pathogeneses and heterogeneity. Selenium (Se) is an essential trace element for human and animal nutrition. It has been shown that supplementation with two organic forms of Se, Se-enriched yeast (Se-yeast) and selenomethionine (Se-Met), could improve cognitive impairment, reverse synaptic deficits and mitigate tau pathology in triple-transgenic (3× Tg) AD mice. Se-yeast is well known for its high Se-Met content, which may mediate its anti-AD effects. In addition, a large amount of the physiological and biochemical mechanisms of these two Se drugs in the amelioration AD pathology remains unknown. In this study, the content of Se-yeast aside from Se was analyzed, and the effects of Se-Met and Se-yeast on 3× Tg-AD mice were investigated and compared. The results showed that both Se-Met and Se-yeast not only significantly increased the Se levels, enhanced the antioxidant capacity and improved the cognitive decline in the model, but also decreased the Aβ and tau pathologies in the brain tissue of the AD mice. Moreover, the ability of Se-Met to increase the Se levels in different tissues of the AD mice was more significant than that of Se-yeast. However, the positive effect of Se-yeast on improving the cognitive ability of the AD mice was better than that of Se-Met, likely due to the various elements, vitamins and other nutrients in Se-yeast. Collectively, these results suggest that Se-yeast has potential as a clinical health product or drug for AD but that Se-Met, as a pure organic Se compound, is more suitable for studying the therapeutic mechanism of Se because of its comprehensive effects on AD.

Effect of long-term nutraceutical and dietary supplement use on cognition in the elderly: a 10-year systematic review of randomised controlled trials

Nutraceuticals have generated interest as a way to mitigate the cognitive decline in older adults. The aim of this systematic review was to determine the evidence for these claims from the scientific literature in randomised, double-blinded, controlled trials (duration: ≥1 year; participants: n≥100; age(mean): ≥65 years). Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched four electronic databases (PubMed, Scopus, CINAHL and Web of Science) and identified twenty-five studies published between the 15·June·2006 and 14·June·2016. Interventions included B-vitamins, n-3 fatty acids, antioxidant vitamins and herbs. Of the B-vitamin studies, four found benefits to cognition with supplementation. The first of these B-vitamin studies, in individuals with mild cognitive impairment (n 266; duration=2 years), included benefit to executive function (P=0·015) and improvements in the Mini-Mental State Examination (MMSE) among participants with baseline homocysteine above 11·3 µmol/l (P<0·001). In the same sample, the second study found cognitive benefits of B-vitamins dependent on the higher baseline plasma n-3 fatty acid status. The third B-vitamin study (n 900; duration=2 years) reported improved performance in immediate (P=0·046) and delayed recall (P=0·013), whereas the fourth study (n 856; duration=2 years) reported slower rate of cognitive decline in the MMSE (P=0·05). One study investigating DHA treatment (n 402; duration=1·5 years) revealed the slower rate of cognitive change in apoE e4 non-carriers (P=0·03). As only five included studies revealed notable benefits, presently based on the specific compounds explored here, there is not compelling evidence to support the use nutraceuticals to improve cognition in the elderly. Future long-term trials of nutraceuticals should investigate interactions with lifestyle, blood biomarkers and genetic risk factors.

Vitamins Associated with Brain Aging, Mild Cognitive Impairment, and Alzheimer Disease: Biomarkers, Epidemiological and Experimental Evidence, Plausible Mechanisms, and Knowledge Gaps

The key to preventing brain aging, mild cognitive impairment (MCI), and Alzheimer disease (AD) via vitamin intake is first to understand molecular mechanisms, then to deduce relevant biomarkers, and subsequently to test the level of evidence for the impact of vitamins in the relevant pathways and their modulation of dementia risk. This narrative review infers information on mechanisms from gene and metabolic defects associated with MCI and AD, and assesses the role of vitamins using recent results from animal and human studies. Current evidence suggests that all known vitamins and some "quasi-vitamins" are involved as cofactors or influence ≥1 of the 6 key sets of pathways or pathologies associated with MCI or AD, relating to 1) 1-carbon metabolism, 2) DNA damage and repair, 3) mitochondrial function and glucose metabolism, 4) lipid and phospholipid metabolism and myelination, 5) neurotransmitter synthesis and synaptogenesis, and 6) amyloidosis and Tau protein phosphorylation. The contemporary level of evidence for each of the vitamins varies considerably, but it is notable that B vitamins are involved as cofactors in all of the core pathways or pathologies and, together with vitamins C and E, are consistently associated with a protective role against dementia. Outcomes from recent studies indicate that the efficacy and safety of supplementation with vitamins to prevent MCI and the early stages of AD will most likely depend on 1) which pathways are defective, 2) which vitamins are deficient and could correct the relevant metabolic defects, and 3) the modulating impact of nutrient-nutrient and nutrient-genotype interaction. More focus on a precision nutrition approach is required to realize the full potential of vitamin therapy in preventing dementia and to avoid causing harm.