Dietary Intake, Mediterranean Diet Adherence and Caloric Intake in Huntington's Disease: A Review

Nutrition and Huntington's Disease- A Review of Current Practice and Theory

PURPOSE OF REVIEW

Nutition has long been of importance in the care of Huntington's disease (HD). The purpose of this review is to summarize recent research relevant to HD nutrition, and to describe some emerging theoretical approaches to research in this area.

RECENT FINDINGS

Clinical studies have identified swallowing problems and fear of choking as major impediments to maintaining nutritional status with HD. Tube feeding is associated with co-morbidities, and provides limited benefits. Non-human models of HD have been utilized to study diets and supplements. Application of findings from these models to humans has not been shown to be of comparable benefit. While studies of nutritional factors in non-human models of HD have shown some promising results, trials in humans have found little efficacy for diets or supplements. The complexity of human metabolic pathways may require a more sophisticated omics approach to identify and study more beneficial interventions.

Small organism models for mode of action research on anti-ageing and nootropic herbs, foods, and formulations

With global increase in ageing population along with increasing age-related neurodegenerative diseases (NDs), development of sustainable, safe and effective solutions for promoting healthy ageing and preventing diseases has become a priority. Traditional healthcare systems/medicines prescribe several herbs, foods and formulations to promote healthy ageing and prevent and/or treat age-related diseases. However, the scientific data elucidating their mechanism of action is very limited and deeper research using different models is warranted for timely and wider use. The clinical studies and research with higher model organisms, although useful, have several practical, technical, and financial limitations. Conversely, small organism models like Yeast, Roundworm, Fruit fly, and Zebrafish, which have genetic similarities to humans, can replicate the disease features and provide behavioural, cellular and molecular insights. The common features of ageing and NDs, like amyloid protein aggregations, oxidative stress, energy dysregulation, inflammation and neurodegeneration can be mimicked in the small organism models for Alzheimer's, Parkinson's, Huntington's diseases, and Amyotrophic Lateral Sclerosis. This review focuses on small organism model- based research unveiling interesting modes of action and synergistic effects of herbal extracts, foods, and formulations, which are indicated especially for healthy ageing and management of NDs. This will provide leads for the quick and sustainable development of scientifically evaluated solutions for clinically relevant, age-related conditions.

Brain-Periphery Interactions in Huntington's Disease: Mediators and Lifestyle Interventions

Prominent pathological features of Huntington's disease (HD) are aggregations of mutated Huntingtin protein (mHtt) in the brain and neurodegeneration, which causes characteristic motor (such as chorea and dystonia) and non-motor symptoms. However, the numerous systemic and peripheral deficits in HD have gained increasing attention recently, since those factors likely modulate disease progression, including brain pathology. While whole-body metabolic abnormalities and organ-specific pathologies in HD have been relatively well described, the potential mediators of compromised inter-organ communication in HD have been insufficiently characterized. Therefore, we applied an exploratory literature search to identify such mediators. Unsurprisingly, dysregulation of inflammatory factors, circulating mHtt, and many other messenger molecules (hormones, lipids, RNAs) were found that suggest impaired inter-organ communication, including of the gut-brain and muscle-brain axis. Based on these findings, we aimed to assess the risks and potentials of lifestyle interventions that are thought to improve communication across these axes: dietary strategies and exercise. We conclude that appropriate lifestyle interventions have great potential to reduce symptoms and potentially modify disease progression (possibly via improving inter-organ signaling) in HD. However, impaired systemic metabolism and peripheral symptoms warrant particular care in the design of dietary and exercise programs for people with HD.

Dietary fasting and time-restricted eating in Huntington's disease: therapeutic potential and underlying mechanisms

Huntington's disease (HD) is a devastating neurodegenerative disorder caused by aggregation of the mutant huntingtin (mHTT) protein, resulting from a CAG repeat expansion in the huntingtin gene HTT. HD is characterized by a variety of debilitating symptoms including involuntary movements, cognitive impairment, and psychiatric disturbances. Despite considerable efforts, effective disease-modifying treatments for HD remain elusive, necessitating exploration of novel therapeutic approaches, including lifestyle modifications that could delay symptom onset and disease progression. Recent studies suggest that time-restricted eating (TRE), a form of intermittent fasting involving daily caloric intake within a limited time window, may hold promise in the treatment of neurodegenerative diseases, including HD. TRE has been shown to improve mitochondrial function, upregulate autophagy, reduce oxidative stress, regulate the sleep-wake cycle, and enhance cognitive function. In this review, we explore the potential therapeutic role of TRE in HD, focusing on its underlying physiological mechanisms. We discuss how TRE might enhance the clearance of mHTT, recover striatal brain-derived neurotrophic factor levels, improve mitochondrial function and stress-response pathways, and synchronize circadian rhythm activity. Understanding these mechanisms is critical for the development of targeted lifestyle interventions to mitigate HD pathology and improve patient outcomes. While the potential benefits of TRE in HD animal models are encouraging, future comprehensive clinical trials will be necessary to evaluate its safety, feasibility, and efficacy in persons with HD.

The microbiota-gut-brain axis in Huntington's disease: pathogenic mechanisms and therapeutic targets

Huntington's disease (HD) is a currently incurable neurogenerative disorder and is typically characterized by progressive movement disorder (including chorea), cognitive deficits (culminating in dementia), psychiatric abnormalities (the most common of which is depression), and peripheral symptoms (including gastrointestinal dysfunction). There are currently no approved disease-modifying therapies available for HD, with death usually occurring approximately 10-25 years after onset, but some therapies hold promising potential. HD subjects are often burdened by chronic diarrhea, constipation, esophageal and gastric inflammation, and a susceptibility to diabetes. Our understanding of the microbiota-gut-brain axis in HD is in its infancy and growing evidence from preclinical and clinical studies suggests a role of gut microbial population imbalance (gut dysbiosis) in HD pathophysiology. The gut and the brain can communicate through the enteric nervous system, immune system, vagus nerve, and microbiota-derived-metabolites including short-chain fatty acids, bile acids, and branched-chain amino acids. This review summarizes supporting evidence demonstrating the alterations in bacterial and fungal composition that may be associated with HD. We focus on mechanisms through which gut dysbiosis may compromise brain and gut health, thus triggering neuroinflammatory responses, and further highlight outcomes of attempts to modulate the gut microbiota as promising therapeutic strategies for HD. Ultimately, we discuss the dearth of data and the need for more longitudinal and translational studies in this nascent field. We suggest future directions to improve our understanding of the association between gut microbes and the pathogenesis of HD, and other 'brain and body disorders'.

The Role of Micronutrients in Neurological Disorders

Trace elements and vitamins, collectively known as micronutrients, are essential for basic metabolic reactions in the human body. Their deficiency or, on the contrary, an increased amount can lead to serious disorders. Research in recent years has shown that long-term abnormal levels of micronutrients may be involved in the etiopathogenesis of some neurological diseases. Acute and chronic alterations in micronutrient levels may cause other serious complications in neurological diseases. Our aim was to summarize the knowledge about micronutrients in relation to selected neurological diseases and comment on their importance and the possibilities of therapeutic intervention in clinical practice.

Investigating the Dietary Intake Using the CyFFQ Semi-Quantitative Food Frequency Questionnaire in Cypriot Huntington's Disease Patients

Huntington's disease (HD) is a rare progressive neurodegenerative disease characterised by autosomal dominant inheritance. The past decade saw a growing interest in the associations between the Mediterranean Diet (MD) and HD risk and outcomes. The aim of this case-control study was to assess the dietary intake and habits of Cypriot HD patients, comparing them to gender and age-matched controls, using the Cyprus Food Frequency Questionnaire (CyFFQ) and to assess adherence to the MD by disease outcomes. The method relied on the validated CyFFQ semi-quantitative questionnaire to assess energy, macro- and micronutrient intake over the past year in n = 36 cases and n = 37 controls. The MedDiet Score and the MEDAS score were used to assess adherence to the MD. Patients were grouped based on symptomatology such as movement and cognitive and behavioral impairment. The two-sample Wilcoxon rank-sum (Mann-Whitney) test was used to compare cases vs. controls. Statistically significant results were obtained for energy intake (kcal/day) (median (IQR): 4592 (3376) vs. 2488 (1917); p = 0.002) from cases and controls. Energy intake (kcal/day) (median (IQR): 3751 (1894) vs. 2488 (1917); p = 0.044) was also found to be significantly different between asymptomatic HD patients and controls. Symptomatic patients were also different from controls in terms of energy intake (kcal/day) (median (IQR): 5571 (2907) vs. 2488 (1917); p = 0.001); % energy monounsaturated fatty acids (median (IQR): 13.4 (5.2) vs. 15.5 (5.7); p = 0.0261) and several micronutrients. A significant difference between asymptomatic and symptomatic HD patients was seen in the MedDiet score (median (IQR): 31.1 (6.1) vs. 33.1 (8.1); p = 0.024) and a significant difference was observed between asymptomatic HD patient and controls (median (IQR): 5.5 (3.0) vs. 8.2 (2.0); p = 0.014) in the MEDAS score. This study confirmed previous findings that HD cases have a significantly higher energy intake than controls, revealing differences in macro and micronutrients and adherence to the MD by both patients and controls and by HD symptom severity. These findings are important as they are an effort to guide nutritional education within this population group and further understand diet-disease associations.

Rehabilitation outcomes in Huntington disease patients with low body mass index

OBJECTIVES

A catabolic state and a progressive body weight loss are a well-documented hallmark of Huntington Disease (HD). No study is still available on the effectiveness of intensive in-hospital rehabilitation in HD patients with low body mass index (BMI).

METHODS

Twenty HD patients with low BMI value were enrolled in this study. Disease severity was assessed before and after rehabilitation by the Barthel Index, the Total Functional Capacity Scale, and the Physical Performance Test.

RESULTS

BMI-scores correlated with clinical measures before and after rehabilitation. All patients showed an improvement in outcome measures (p<0.001), and an increase in BMI values (p<0.001) after rehabilitation. Effectiveness of rehabilitation correlated with the values of BMI assessed before reheducational programs (p=0.024) and with BMI values observed in each patient in the three months before admission to hospital (p=0.002).

CONCLUSIONS

Findings of the current study show that the effectiveness of the rehabilitation is positively correlated with the BMI values and confirm the efficacy of in-hospital intensive rehabilitation as a valid strategy finalized to improve neuromotor performances and global functional recovery even in HD patients with low BMI and at risk of malnutrition.

Converging evidence in support of omega-3 polyunsaturated fatty acids as a potential therapy for Huntington's disease symptoms

Huntington's disease (HD) is a genetic, inexorably fatal neurodegenerative disease. Patient average survivability is up to 20 years after the onset of symptoms. Those who suffer from the disease manifest motor, cognitive, and psychiatric impairments. There is indirect evidence suggesting that omega-3 polyunsaturated fatty acids (ω-3 PUFA) could have alleviating effects on most of HD symptoms. These include beneficial effects against cachexia and weight loss, decrease of cognitive impairment over time, and improvement of psychiatric symptoms such as depression and irritability. Furthermore, there is a positive correlation between consumption of ω-3 PUFAs in diets and prevalence of HD, as well as direct effects on the disease via release of serotonin. Unfortunately, to date, very few studies have examined the effects of ω-3 PUFAs in HD, both on the symptoms and on disease progression. This paper reviews evidence in the literature suggesting that ω-3 PUFAs can be used in neurodegenerative disorders. This information can be extrapolated to support further research of ω-3 PUFAs and their potential use for HD treatment.

Quantifying the Onset of Unintended Weight Loss in Huntington's Disease: A Retrospective Analysis of Enroll-HD

BACKGROUND

Unintended weight loss and decreased body mass indexes (BMIs) are common symptoms of individuals with manifest HD. It is unknown at what point during disease progression weight loss starts to accelerate relative to a healthy individual's weight and when recommended interventions should be initiated to have the strongest impact on patient care.

OBJECTIVE

The objective of this study was to identify a point in time relative to age at motor onset when the decline in weight in HD starts to accelerate relative to a non-HD population. The relationship between initiation of weight loss interventions and changes in weight loss was also explored.

METHODS

Participants from the fifth version of the Enroll-HD study were identified for this research. Linear mixed-effects piecewise regression models were used to estimate the point in time relative to the reported age of motor onset in which BMI started to decline in participants with HD compared to healthy non-HD controls. A post-hoc descriptive analysis was performed to look at when nutritional supplements and swallow therapy were initiated in participants with HD relative to motor onset.

RESULTS

BMI decline in the HD group began to accelerate compared to controls approximately 5.7 years after the reported age of motor onset (95% CI: 4.7-6.9). The average initiation times of swallow therapy and nutritional supplements were 7.7 years (SD = 5.5 years) and 6.7 years (SD = 6.5 years) after motor onset, respectively.

CONCLUSION

Our findings suggest a potential point for intervention of nutrition programs or therapies used to prevent future weight loss.

Diet, Nutrition and Chronic Degenerative Diseases

Chronic degenerative diseases (CDDs), represented mainly by obesity, cardiovascular disease (CVD), diabetes, chronic kidney disease (CKD), inflammatory bowel diseases, osteoporosis, sarcopenia, neurodegenerative diseases such as Huntington's disease (HD), rheumatoid arthritis (RA), chronic respiratory diseases, and many cancers, have been, up to now, the most frequent causes of prolonged disability and death worldwide [...].

Geographic differences in the incidence of Huntington's disease in Sardinia, Italy

BACKGROUND

The frequency of Huntington's disease (HD) may vary considerably, with higher estimates in non-Asian populations. We have recently examined the prevalence of HD in the southern part of Sardinia, a large Italian Mediterranean island that is considered a genetic isolate. We observed regional microgeographic differences in the prevalence of HD across the study area similar to those recently reported in other studies conducted in European countries. To explore the basis for this variability, we undertook a study of the incidence of HD in Sardinia over a 10-year period, 2009 to 2018.

METHODS

Our research was conducted in the 5 administrative areas of Sardinia island. Case patients were ascertained through multiple sources in Sardinia and Italy.

RESULTS

During the incidence period 53 individuals were diagnosed with clinically manifested HD. The average annual incidence rate 2009-2018 was 2.92 per 10⁶ persons-year (95% CI, 2.2 to 3.9). The highest incidence rate was observed in South Sardinia (6.3; 95% CI, 4.2-9.5). This rate was significantly higher (p<0.01) than the rates from Cagliari, Oristano, and Sassari provinces but did not significantly differ (p = 0.38) from the Nuoro rate.

CONCLUSIONS

The overall incidence of HD in Sardinia is close to the correspondent estimates in Mediterranean countries. Our findings highlight also the possibility of local microgeographic variations in the epidemiology of HD that might reflect several factors, including a possible founder effect in the rural areas of South Sardinia and Nuoro.