Primary prevention of Alzheimer's disease: is it an attainable goal?

Importance of oral health in mental health disorders: An updated review

Background

Mental disorders are indeed an expanding threat, which requires raised awareness, education, prevention, and treatment initiatives nationally and globally. This review presents an updated review on the relationships between oral health and mental health disorders and the importance of oral health in mental health disorders.

Method

A literature search was done regarding mental disorders and oral health approaches in Google Scholar and PubMed from the year 1995 until 2023. All the English-language papers were evaluated based on the inclusion criteria. Publications included original research papers, review articles and book chapters.

Results

Common mental disorders include depression, anxiety, bipolar disorder, Schizophrenia, dementia, and alcohol and drug use disorders. The interplay of oral health and mental disorders involves dysregulated microbiome, translocated bacteria, and systemic inflammation, among others.

Conclusion

There is a complex relationship between mental disorders and oral diseases. Various oral health problems are associated with mental health problems. The interplay of oral health and mental disorders involves dysregulated microbiome, translocated bacteria, and systemic inflammation, among others. Mental health nurses including physicians and dental professionals should be involved in the oral health care of mental health disorder patients. Therefore, multidisciplinary should be involved in the care of mental health disorders, and they should consider oral health care as an essential part of their care for patients with mental health disorders. Future investigations should strive to elucidate the exact biological relationships, to develop new directions for treatment.

Associations Between Korean Coronary Heart Disease Risk Score and Cognitive Function in Dementia-Free Korean Older Adults

BACKGROUND

Cardiovascular risk is a modifiable factor that can help prevent dementia. Given the dearth of optimal treatment options, managing dementia risk factors is crucial. We examined the association between cardiovascular risk, as measured by the Korean coronary heart disease risk score (KRS), and cognitive function in dementia-free elderly individuals.

METHODS

We enrolled 8,600 individuals (average age: 69.74 years; 5,206 women) who underwent a medical evaluation from the National Health Insurance Service. KRS was calculated using age, sex, blood pressure, lipid profile, diabetes, and smoking status. Cognitive function was evaluated using Korean Dementia Screening Questionnaire-Cognition (KDSQ-C). Scores of ≥ 6 indicated a cognitive decline. Logistic regression analysis was used to estimate the odds ratio (OR) and 95% confidence interval (CI). Weight, height, stroke history, coronary heart disease history, alcohol consumption, and physical activity engagement were adjusted.

RESULTS

The lowest, middle, and highest groups, according to the KRS, were 5,923 (68.9%), 2,343 (27.2%), and 334 (3.9%), respectively. The highest KRS group in all participants exhibited a greater risk of cognitive decline than the lowest KRS group (OR, 1.339; 95% CI, 1.034-1.734; P = 0.027). The highest KRS female group aged 71-75 years old exhibited greater cognitive decline than the corresponding lowest KRS group (OR, 1.595; 95% CI, 1.045-2.434; P = 0.031).

CONCLUSION

Individuals with high cardiovascular risk were associated with poorer cognitive function than those with low risk, especially older women. Cardiovascular risk factors should be carefully managed to promote healthy mental aging in dementia-free elderly individuals.

Dementia Prevention in Clinical Practice

Over 55 million people globally are living with dementia and, by 2050, this number is projected to increase to 131 million. This poses immeasurable challenges for patients and their families and a significant threat to domestic and global economies. Given this public health crisis and disappointing results from disease-modifying trials, there has been a recent shift in focus toward primary and secondary prevention strategies. Approximately 40% of Alzheimer's disease (AD) cases, which is the most common form of dementia, may be prevented or at least delayed. Success of risk reduction studies through addressing modifiable risk factors, in addition to the failure of most drug trials, lends support for personalized multidomain interventions rather than a "one-size-fits-all" approach. Evolving evidence supports early intervention in at-risk patients using individualized interventions directed at modifiable risk factors. Comprehensive risk stratification can be informed by emerging principals of precision medicine, and include expanded clinical and family history, anthropometric measurements, blood biomarkers, neurocognitive evaluation, and genetic information. Risk stratification is key in differentiating subtypes of dementia and identifies targetable areas for intervention. This article reviews a clinical approach toward dementia risk stratification and evidence-based prevention strategies, with a primary focus on AD.

Association of Cardiovascular and Alzheimer's Disease Risk Factors with Intracranial Arterial Blood Flow in Whites and African Americans

BACKGROUND

Alzheimer's disease (AD) has a higher prevalence among African Americans. Targeting cardiovascular and metabolic risk factors may be potential mechanisms to modify AD risk and address racial/ethnic disparities in AD dementia.

OBJECTIVE

This study investigated relationships among cardiovascular and metabolic risk factors, APOE genotype, AD biomarkers, and intracranial arterial blood flow in Whites and African Americans enriched for AD risk.

METHODS

399 cognitively unimpaired adults from the Wisconsin Alzheimer's Disease Research Center completed physical and neuroimaging examinations. A 4D Flow MRI sequence (phase-contrast vastly under sampled isotropic projection imaging) measured intracranial arterial flow in the Circle of Willis. Linear mixed-effects regression models estimated relationships between risk factors and intracranial arterial flow and tested interactions with racial group, APOE genotype, and AD biomarkers, with separate models per risk factor.

RESULTS

Higher fasting glucose was associated with lower intracranial arterial flow; no additional relationships between flow and risk factors were observed. Main effects of racial group were observed, without an interaction, indicating lower flow in African Americans compared to Whites. In race-stratified analyses, higher glucose and triglycerides were associated with lower flow for African Americans, but not for Whites. No main effects or interactions among risk factors, APOE, or AD biomarkers, and flow were observed.

CONCLUSION

Elevated fasting glucose and triglycerides were associated with lower intracranial arterial flow; these relationships were more prominent in African Americans. Targeting metabolic risk factors may impact intracranial arterial health. Additional research is needed to determine if this will impact disparities in dementia prevalence.

Network Simulations Reveal Molecular Signatures of Vulnerability to Age-Dependent Stress and Tau Accumulation

Alzheimer’s disease (AD) is the leading cause of dementia and one of the most common causes of death worldwide. As an age-dependent multifactorial disease, the causative triggers of AD are rooted in spontaneous declines in cellular function and metabolic capacity with increases in protein stressors such as the tau protein. This multitude of age-related processes that cause neurons to change from healthy states to ones vulnerable to the damage seen in AD are difficult to simultaneously investigate and even more difficult to quantify. Here we aimed to diminish these gaps in our understanding of neuronal vulnerability in AD development by using simulation methods to theoretically quantify an array of cellular stress responses and signaling molecules. This temporally-descriptive molecular signature was produced using a novel multimethod simulation approach pioneered by our laboratory for biological research; this methodology combines hierarchical agent-based processes and continuous equation-based modeling in the same interface, all while maintaining intrinsic distributions that emulate natural biological stochasticity. The molecular signature was validated for a normal organismal aging trajectory using experimental longitudinal data from Caenorhabditis elegans and rodent studies. In addition, we have further predicted this aging molecular signature for cells impacted by the pathogenic tau protein, giving rise to distinct stress response conditions needed for cytoprotective aging. Interestingly, our simulation experiments showed that oxidative stress signaling (via daf-16 and skn-1 activities) does not substantially protect cells from all the early stressors of aging, but that it is essential in preventing a late-life degenerative cellular phenotype. Together, our simulation experiments aid in elucidating neurodegenerative triggers in the onset of AD for different genetic conditions. The long-term goal of this work is to provide more detailed diagnostic and prognostic tools for AD development and progression, and to provide more comprehensive preventative measures for this disease.

Therapeutic Potential of Multifunctional Tacrine Analogues

Abstract: Tacrine is a potent inhibitor of cholinesterases (acetylcholinesterase and butyrylcholinesterase) that shows limiting clinical application by liver toxicity. In spite of this, analogues of tacrine are considered as a model inhibitor of cholinesterases in the therapy of Alzheimer’s disease. The interest in these compounds is mainly related to a high variety of their structure and biological properties. In the present review, we have described the role of cholinergic transmission and treatment strategies in Alzheimer’s disease as well as the synthesis and biological activity of several recently developed classes of multifunctional tacrine analogues and hybrids, which consist of a new paradigm to treat Alzheimer’s disease. We have also reported potential of these analogues in the treatment of Alzheimer’s diseases in various experimental systems.

Prospective of managing impaired brain insulin signalling in late onset Alzheimers disease with excisting diabetic drugs

Late onset Alzheimer's disease (AD) is the most common cause of dementia among elderly. The exact cause of the disease is until now unknown and there is no complete cure for the disease. Growing evidence suggest that AD is a metabolic disorder associated with impairment in brain insulin signalling. These findings enriched the scope for the repurposing of diabetic drugs in AD management. Even though many of these drugs are moving in a positive direction in the ongoing clinical studies, the extent of the success has seen to influence by several properties of these drugs since they were originally designed to manage the peripheral insulin resistance. In depth understandings of these properties is hence highly significant to optimise the use of diabetic drugs in the clinical management of AD; which is the primary aim of the present review article.

Integrating Health Promotion Into Physical Therapy Practice to Improve Brain Health and Prevent Alzheimer Disease

BACKGROUND AND PURPOSE

Alzheimer disease is the most common cause of dementia, and brain pathology appears years before symptoms are evident. Primary prevention through health promotion can incorporate lifestyle improvement across the lifespan. Risk factor assessment and identifying markers of disease might also trigger preventive measures needed for high-risk individuals and groups.

SUMMARY OF KEY POINTS

Many potential risk factors are modifiable through exercise, and may be responsive to early intervention strategies to reduce the downward slope toward disability. Through the use of common clinical tests to identify cognitive and noncognitive functional markers of disease, detection and intervention can occur at earlier stages, including preclinical stages of disease. Physical activity and exercise interventions to address modifiable risk factors and impairments can play a pivotal role in the prevention and delay of functional decline, ultimately reducing the incidence of dementia. This article discusses prevention, prediction, plasticity, and participation in the context of preserving brain health and preventing Alzheimer disease and related dementias in aging adults.

RECOMMENDATIONS FOR CLINICAL PRACTICE

Rehabilitation professionals have opportunities to slow disease progression through research, practice, and education initiatives. From a clinical perspective, interventions that target brain health through lifestyle changes and exercise interventions show promise for preventing stroke and associated neurovascular diseases in addition to dementia. Physical therapists are well positioned to integrate primary health promotion into practice for the prevention of dementia and other neurological conditions in older adults.

Effects of smartphone-based memory training for older adults with subjective memory complaints: a randomized controlled trial

OBJECTIVES

We explored whether newly developed application (Smartphone-based brain Anti-aging and memory Reinforcement Training, SMART) improved memory performance in older adults with subjective memory complaints (SMC).

METHOD

A total of 53 adults (range: 50-68 years; 52.8% female) were randomized into either one of two intervention groups [SMART (n = 18) vs. Fit Brains® (n = 19)] or a wait-list group (n = 16). Participants in the intervention groups underwent 15-20 minutes of training per day, five days per week for 8 weeks. We used objective cognitive measures to evaluate changes with respect to four domains: attention, memory, working memory (WM), and response inhibition. In addition, we included self-report questionnaires to assess levels of SMC, depression, and anxiety.

RESULTS

Total WM quotient [t(17) = 6.27, p < .001] as well as auditory-verbal WM score [t(17) = 4.45, p < .001] increased significantly in the SMART group but not in the control groups. Self-reports of memory contentment, however, increased in the Fit Brains® group only [t(18) = 2.12, p < .05).

CONCLUSION

Use of an 8-week smartphone-based memory training program may improve WM function in older adults. However, objective improvement in performance does not necessarily lead to decreased SMC.

Elucidating the link between the modifiable risk factors of Alzheimer's disease and neuroinflammation

Increased worldwide longevity through medical interventions, although beneficial, has allowed the age-related Alzheimer's disease (AD) to become an epidemic of the 21st century. AD pathology involves adverse activation of microglia, the immune cells of the brain and resulting chronic neuroinflammation. Certain diets, physical inactivity and Type 2 diabetes mellitus have been identified as the risk factors for developing AD, which may increase the risk of AD by neuroimmune mechanisms primarily through the overactivation of microglia. Thus, modifying these risk factors may represent an alternative therapeutic strategy for lowering the incidence of AD. We highlight the link between select modifiable risk factors and neuroimmune mechanisms, and demonstrate that by controlling microglial activation and neuroinflammation the prevalence of AD may be decreased.

Omega-3 Polyunsaturated Fatty Acids and Oxylipins in Neuroinflammation and Management of Alzheimer Disease

Alzheimer disease (AD) is becoming one of the most prevalent neurodegenerative conditions worldwide. Although the disease progression is becoming better understood, current medical interventions can only ameliorate some of the symptoms but cannot slow disease progression. Neuroinflammation plays an important role in the advancement of this disorder, and n-3 (ω-3) polyunsaturated fatty acids (PUFAs) are involved in both the reduction in and resolution of inflammation. These effects may be mediated by the anti-inflammatory and proresolving effects of bioactive lipid mediators (oxylipins) derived from n-3 PUFAs [eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] in fish oil. Although interventions have generally used fish oil containing both EPA and DHA, several studies that used either EPA or DHA alone or specific oxylipins derived from these fatty acids indicate that they have distinct effects. Both DHA and EPA can reduce neuroinflammation and cognitive decline, but EPA positively influences mood disorders, whereas DHA maintains normal brain structure. Fewer studies with a plant-derived n-3 PUFA, α-linolenic acid, suggest that other n-3 PUFAs and their oxylipins also may positively affect AD. Further research identifying the unique anti-inflammatory and proresolving properties of oxylipins from individual n-3 PUFAs will enable the discovery of novel disease-management strategies in AD.

[Development of preclinical diagnosis and preventive treatment of neurodegenerative diseases]

Neurodegenerative diseases (NDD) are serious fatal neurological and mental diseases that resulted in disability and fethal outcome. Based on the advances of basic sciences over the last two decades, new knowledge on the risk factors for NDD and molecular mechanisms of the pathogenesis are obtained. It has been shown that the accelerated process of neuronal death which is the main cause of NDD development begins long before the appearance of clinical symptoms. The first symptoms appeared only after the death of most specific regulatory neurons and exhaustion of brain compensatory reserve. Only at that time, one can make the diagnosis and start traditional treatment of patients that accounts for the extremely low efficacy of the latter. Currently, complex preclinical diagnosis based on the identification of relatively specific clinical precursors and peripheral biomarkers has been developing. Development of preclinical diagnosis and preventive treatment is a strategic issue of modern neurology and psychiatry. The resolution of this issue allows to consider NDD as cured, but not fatal, diseases.

Lipid Raft Size and Lipid Mobility in Non-raft Domains Increase during Aging and Are Exacerbated in APP/PS1 Mice Model of Alzheimer's Disease. Predictions from an Agent-Based Mathematical Model

A connection between lipid rafts and Alzheimer's disease has been studied during the last decades. Mathematical modeling approaches have recently been used to correlate the effects of lipid composition changes in the physicochemical properties of raft-like membranes. Here we propose an agent based model to assess the effect of lipid changes in lipid rafts on the evolution and progression of Alzheimer's disease using lipid profile data obtained in an established model of familial Alzheimer's disease. We have observed that lipid raft size and lipid mobility in non-raft domains are two main factors that increase during age and are accelerated in the transgenic Alzheimer's disease mouse model. The consequences of these changes are discussed in the context of neurotoxic amyloid β production. Our agent based model predicts that increasing sterols (mainly cholesterol) and long-chain polyunsaturated fatty acids (LCPUFA) (mainly DHA, docosahexaenoic acid) proportions in the membrane composition might delay the onset and progression of the disease.

Alzheimer's Disease Risk and Progression: The Role of Nutritional Supplements and their Effect on Drug Therapy Outcome

Alzheimer's disease (AD) is the most common neurodegenerative disease in the elderly population. Despite significant advancements in understanding the genetic and molecular basis of AD, the pathology still lacks treatments that can slow down or reverse the progression of cognitive deterioration. Recently, the relationship between nutrient deficiency and dementia onset has been highlighted. AD is in fact a multifactorial pathology, so that a multi-target approach using combinations of micronutrients and drugs could have beneficial effects on cognitive function in neurodegenerative brain disorders leading to synaptic degeneration. Primarily, this review examines the most recent literature regarding the effects of nutrition on the risk/progression of the disease, focusing attention mostly on antioxidants agents, polyunsaturated fatty acids and metals. Secondly, it aims to figure out if nutritional supplements might have beneficial effects on drug therapy outcome. Even if nutritional supplements showed contrasting evidence of a likely effect of decreasing the risk of AD onset that could be studied more deeply in other clinical trials, no convincing data are present about their usefulness in combination with drug therapies and their effectiveness in slowing down the disease progression.

Omega-3 Fatty Acids in Early Prevention of Inflammatory Neurodegenerative Disease: A Focus on Alzheimer's Disease

Alzheimer's disease (AD) is the leading cause of dementia and the most common neurodegenerative disease in the elderly. Furthermore, AD has provided the most positive indication to support the fact that inflammation contributes to neurodegenerative disease. The exact etiology of AD is unknown, but environmental and genetic factors are thought to contribute, such as advancing age, family history, presence of chronic diseases such as cardiovascular disease (CVD) and diabetes, and poor diet and lifestyle. It is hypothesised that early prevention or management of inflammation could delay the onset or reduce the symptoms of AD. Normal physiological changes to the brain with ageing include depletion of long chain omega-3 fatty acids and brains of AD patients have lower docosahexaenoic acid (DHA) levels. DHA supplementation can reduce markers of inflammation. This review specifically focusses on the evidence in humans from epidemiological, dietary intervention, and supplementation studies, which supports the role of long chain omega-3 fatty acids in the prevention or delay of cognitive decline in AD in its early stages. Longer term trials with long chain omega-3 supplementation in early stage AD are warranted. We also highlight the importance of overall quality and composition of the diet to protect against AD and dementia.