Obesity and neurological disorders: Dietary perspective of a global menace

Advancements in Single-Cell RNA Sequencing Research for Neurological Diseases

Neurological diseases are a major cause of the global burden of disease. Although the mechanisms of the occurrence and development of neurological diseases are not fully clear, most of them are associated with cells mediating neuroinflammation. Yet medications and other therapeutic options to improve treatment are still very limited. Single-cell RNA sequencing (scRNA-seq), as a delightfully potent breakthrough technology, not only identifies various cell types and response states but also uncovers cell-specific gene expression changes, gene regulatory networks, intercellular communication, and cellular movement trajectories, among others, in different cell types. In this review, we describe the technology of scRNA-seq in detail and discuss and summarize the application of scRNA-seq in exploring neurological diseases, elaborating the corresponding specific mechanisms of the diseases as well as providing a reliable basis for new therapeutic approaches. Finally, we affirm that scRNA-seq promotes the development of the neuroscience field and enables us to have a deeper cellular understanding of neurological diseases in the future, which provides strong support for the treatment of neurological diseases and the improvement of patients' prognosis.

Enhancing the lipid stability of foods of animal origin using edible packaging systems

Foods of animal origin are prone to oxidation due to their high lipid content and fatty acid profile. Edible packaging systems have evolved as a new way of preserving animal-derived foods and have been reported to retard lipid oxidation using antioxidant molecules from side-streams, waste, and agricultural by-products. Studies have evaluated previously undocumented film materials and novel bioactive molecules as additives for edible packaging for animal-derived foods. However, none of the studies is specifically focused on evaluating the packaging systems available for enhancing lipid stability. This paper thoroughly examines and discusses the application of edible packaging containing novel antioxidant molecules for controlling the lipid oxidation of animal-derived foods. The paper analyses and interprets the main findings of the recently published research papers. The materials and active principles used for enhancing lipid stability have been summarised and the underlying mechanisms discussed in detail. Studies should aim at using cheaper and readily available natural ingredients in future for the production of affordable packaging systems.

Coreopsis tinctoria improves energy metabolism in obese hyperglycemic mice

Coreopsis tinctoria (CT) improves energy metabolism. However, the role of CT in alleviating obesity-induced hyperglycemia by targeting the liver remains unknown. Therefore, this article aims to explore the mechanism by which CT improves energy metabolism and resists hyperglycemia. The water and ethanol extracts of CT were administered to high-fat diet-induced (HFD) obese C57BL/6J mice at a dose of 4 g/kg.bw (low-dose water extract, WL; low-dose ethanol extract, EL) or 10 g/kg.bw (high-dose water extract, WH; high-dose ethanol extract, EH). Mice that consumed a maintenance diet (LFD) were included as blank controls. Network pharmacology, liquid chromatography-mass spectrometry (LC-MS), L02 cell cultivation, and liver transcriptomics were used to examine the mechanism and functional components of CT against obesity-induced hyperglycemia. The results indicated that WL significantly (p < 0.05) alleviated glucose intolerance and insulin resistance in obesity-induced hyperglycemia. Kaempferol is the main active compound of CT, which demonstrated significant (p < 0.05) anti-hyperglycemic effects in obese mice and L02 cells. Finally, kaempferol significantly (p < 0.05; fold change >1.2) shifted the genes involved in carbon metabolism, glycolysis/gluconeogenesis, and the mitogen-activated protein kinase (MAPK) pathways toward the trend of LFD, indicating that it exerts an anti-hyperglycemic effect through these molecular mechanisms. Overall, oral intake of CT lowers blood glucose and improves insulin sensitivity in mice with obesity-induced hyperglycemia. Kaempferol is the primary functional component of CT.

A Comprehensive Review of the Effects of Glycemic Carbohydrates on the Neurocognitive Functions Based on Gut Microenvironment Regulation and Glycemic Fluctuation Control

Improper glycemic carbohydrates (GCs) consumption can be a potential risk factor for metabolic diseases such as obesity and diabetes, which may lead to cognitive impairment. Although several potential mechanisms have been studied, the biological relationship between carbohydrate consumption and neurocognitive impairment is still uncertain. In this review, the main effects and mechanisms of GCs' digestive characteristics on cognitive functions are comprehensively elucidated. Additionally, healthier carbohydrate selection, a reliable research model, and future directions are discussed. Individuals in their early and late lives and patients with metabolic diseases are highly susceptible to dietary-induced cognitive impairment. It is well known that gut function is closely related to dietary patterns. Unhealthy carbohydrate diet-induced gut microenvironment disorders negatively impact cognitive functions through the gut-brain axis. Moreover, severe glycemic fluctuations, due to rapidly digestible carbohydrate consumption or metabolic diseases, can impair neurocognitive functions by disrupting glucose metabolism, dysregulating calcium homeostasis, oxidative stress, inflammatory responses, and accumulating advanced glycation end products. Unstable glycemic status can lead to more severe neurological impairment than persistent hyperglycemia. Slow-digested or resistant carbohydrates might contribute to better neurocognitive functions due to stable glycemic response and healthier gut functions than fully gelatinized starch and nutritive sugars.

Mediation effect of JAK2 methylation on the association between sitting time and abdominal obesity in rural adults

BACKGROUND

Sitting time may affect health by altering the methylation of certain genes. This research aimed to estimate the association of sitting time with abdominal obesity and the role of Janus kinase 2 (JAK2) methylation in the association among rural adults.

METHODS

A total of 1062 rural adults from the Henan Rural Cohort Study were included. Whole blood was used to extract genomic DNA. JAK2 DNA methylation level was assessed by MethylTargetTM. The logistic regression model was utilized to assess the association of sitting time with abdominal obesity, and the possible effect of JAK2 DNA methylation on the association were conducted by using mediation analyses.

RESULTS

Average time of sitting of participants was 7.28 ± 3.37 h/d. For per 1 h increment in sitting time, the odd ratio (OR) and 95% confidence interval (CI) of abdominal obesity was 1.153 (1.095, 1.214) after controlling potential risk factors. Simultaneously, the methylation levels of Chr9: 4985407 site and Chr9: 4985238-4985455 region were negatively correlated with abdominal obesity (OR: 0.549, 95% CI: 0.394, 0.765; OR: 0.189, 95% CI: 0.056, 0.640, respectively). Moreover, Chr9: 4985407 site and Chr9: 4985238-4985455 region methylation levels mediated the association of sitting time with abdominal obesity, and the indirect effects account for 6.78% and 4.24%, respectively.

CONCLUSIONS

Longer sitting time was positively correlated with abdominal obesity in the rural population, and methylation level of JAK2 may be an underlying mediation of the effect.

Preventive Effect of Indian Gooseberry (Phyllanthus emblica L.) Fruit Extract on Cognitive Decline in High-Fat Diet (HFD)-Fed Rats

SCOPE

Methylglyoxal (MG)-derived advanced glycation end products (AGEs) directly bind to the receptor for advanced glycation end products (RAGE), subsequently exacerbating obesity and obesity-induced cognitive decline. Indian gooseberry (Phyllanthus emblica L.) fruit has antiobesity properties. However, the underlying mechanism by which Indian gooseberry fruit prevents obesity-induced cognitive decline remains unclear.

METHODS AND RESULTS

This study aims to investigate the preventive effect of a water extract of Indian gooseberry fruit (WEIG) and its bioactive compound gallic acid (GA) on the obesity-induced cognitive decline through MG suppression and gut microbiota modulation in high-fat diet (HFD)-fed rats. Trapping MG, WEIG, and GA significantly ameliorate fat accumulation in adipose tissue and learning and memory deficits. Mechanistically, WEIG and GA administration effectively reduces brain MG and AGE levels and subsequently reduces insulin resistance, inflammatory cytokines, MDA production, and Alzheimer's disease-related proteins, but increases both antioxidant enzyme activities and anti-inflammatory cytokine with inhibiting RAGE, MAPK, and NF-κB levels in HFD-fed rats. Additionally, WEIG and GA supplementation increases the relative abundances of Bacteroidetes, Gammaproteobacteria, and Parasutterella, which negatively correlate with MG, inflammatory cytokine, and Alzheimer's disease-related protein expressions.

CONCLUSION

This novel finding provides a possible mechanism by which WEIG prevents obesity-induced cognitive decline through the gut-brain axis.

An Energy-Restricted Diet Including Yogurt, Fruit, and Vegetables Alleviates High-Fat Diet-Induced Metabolic Syndrome in Mice by Modulating the Gut Microbiota

BACKGROUND

The importance of the composition of an energy-restricted diet in the treatment of metabolic syndrome (MetS) is unknown.

OBJECTIVES

In this study we aimed to investigate the benefits of a novel dietary treatment (50% calorie restriction diet composed of yogurt, fruit, and vegetables [CR-YD]) in mice with MetS.

METHODS

Forty 7-wk-old male C57BL/6 J mice were randomly assigned to 4 groups (n = 10/group) that were fed for 14 wk ad libitum with a normal diet (ND; 10%:70%:20% energy from fat: carbohydrate: protein) or for 12 wk with a high-fat diet (HFD; 60:20:20) or the HFD followed by 2 wk of feeding with a 50% calorie-restricted HFD (CR-HFD) or YD (CR-YD, 21.2%:65.4%:13.4% energy). Body weight, fat deposition, hepatic steatosis, serum concentrations of inflammatory biomarkers, and glucose homeostasis were assessed. Fecal microbiota transplantation (FMT) was used to validate the roles of gut microbiota in MetS.

RESULTS

The HFD group had 50% greater body weight and 475% greater fat deposition than the ND group (P < 0.05). Compared with the HFD group, the CR-HFD and CR-YD groups had 22% and 31% lower body weight and 49% and 75% less fat deposition, respectively (P < 0.05). Compared with the CR-HFD group, the CR-YD group had 11% lower body weight, 96% less fat deposition, 500% less hepatic steatosis, 75% lower glucose, and 450% more hepatic Akkermansia bacteria (P < 0.05). The CR-YD group also had 50% lower histopathology scores and 1.35-fold higher levels of Claudin4 than the CR-HFD group (P < 0.05). The HFD + CR-YD fecal group had 10.6% lower body weight, 119% lower steatosis, and 17.9% lower glucose (P < 0.05) than the HFD + CR-HFD fecal group.

CONCLUSIONS

Compared with CR alone, the CR-YD diet has a better therapeutic effect in mice with HFD-induced MetS.

Walking and taking vitamin C alleviates oxidative stress and inflammation in overweight students, even in the short-term

Objective

Obese or overweight is a risk factor for some chronic diseases, and oxidative stress and inflammation may be one of the molecular mechanisms leading to the persistence of these chronic diseases. Discovering interventions to alleviate oxidative stress and inflammation in the overweight/obese population, is very important for public health and health education.

Methods

A two-week panel intervention study (Run 0-Run 1-Run 2) was conducted. The subjects were 77 overweight/obese undergraduates attending Dali University, with a BMI>24 kg/m². The physical indices measured at the end of each run included BMI, waist circumference, serum ROS, TNF-α, IL-1β and urinary 8-OHdG. Students were allocated to one of four intervention groups: No intervention (control); walking; taking vitamin C; and walking + taking vitamin C.

Results

The results demonstrated (1) Walking significantly alleviated ROS levels, and this was consistent in Run 1 and Run 2; (2) During Run1, all three intervention modes reduced levels of 8-OHdG, but there was a statistically insignificant increase during Run 2; (3) No alleviating effects of the three intervention modes on TNF-α levels during Run 1 and Run 2 were observed; (4) The alleviating effects of the three intervention modes on IL-1β levels during Run 1 and Run 2 were clear.

Conclusion

Walking and taking vitamin C can reduce levels of ROS, 8-OHdG and IL-1β, but not TNF-α, in overweight/obese participants. These interventions may become potential preventive measures for the overweight against obese-induced oxidative stress and inflammation.

Mitochondrial Oxidative Stress Induces Cardiac Fibrosis in Obese Rats through Modulation of Transthyretin

A proteomic approach was used to characterize potential mediators involved in the improvement in cardiac fibrosis observed with the administration of the mitochondrial antioxidant MitoQ in obese rats. Male Wistar rats were fed a standard diet (3.5% fat; CT) or a high-fat diet (35% fat; HFD) and treated with vehicle or MitoQ (200 μM) in drinking water for 7 weeks. Obesity modulated the expression of 33 proteins as compared with controls of the more than 1000 proteins identified. These include proteins related to endoplasmic reticulum (ER) stress and oxidative stress. Proteomic analyses revealed that HFD animals presented with an increase in cardiac transthyretin (TTR) protein levels, an effect that was prevented by MitoQ treatment in obese animals. This was confirmed by plasma levels, which were associated with those of cardiac levels of both binding immunoglobulin protein (BiP), a marker of ER stress, and fibrosis. TTR stimulated collagen I production and BiP in cardiac fibroblasts. This upregulation was prevented by the presence of MitoQ. In summary, the results suggest a role of TTR in cardiac fibrosis development associated with obesity and the beneficial effects of treatment with mitochondrial antioxidants.

Maqui (Aristotelia chilensis (Mol.) Stuntz): A Natural Antioxidant to Improve Quality of Meat Patties

Aristotelia chilensis is an endemic shrub of the South Pacific with high concentrations of bioactive compounds in its leaves and, therefore, it is highly valued. The effect of Aristotelia chilensis leaf powders (maqui leaf powders; Ma) on the quality and shelf life of beef patties during 7 days of storage was investigated. Five beef patties treatments were prepared: (1) Control without antioxidants (CT); (2) Beef patties with synthetic antioxidants plus color (250 mg/kg) (PL); (3) Beef patties with 500 ppm of maqui leaf powders (Ma500); (4) Beef patties with 1000 ppm of maqui leaf powders (Ma1000); and (5) Beef patties with 2000 ppm of maqui leaf powders (Ma2000). The quality of the beef patties was evaluated on day 0 and day 7 of storage by physicochemical analysis (moisture, ash and lipid content, color, pH, fatty acid profile and lipid oxidation) and organoleptic analysis. The addition of maqui leaf powders did not produce changes in the proximate composition of the beef patties. The pH for all treatments showed a range of 5.50−5.75 and significant differences (p < 0.05) were observed at the beginning and end of storage. The pH of the control beef patties increased during storage while the pH of the beef patties with synthetic and natural antioxidants decreased. Redness (a*) was the color indicator that was mostly affected by the inclusion of 1000 ppm and 2000 ppm powders. High lipid oxidation was observed in control samples on the seventh day of storage due to the high percentage of fat used in the formulation and the absence of any antioxidant. However, the Ma500, Ma1000, and Ma2000 treatments presented the lowest lipid oxidation rates (42.05%, 40.29%, and 43.14%, respectively) in comparison with the synthetic antioxidant (52.23%). This lipid inhibition is related to the strong antioxidant activity (29.75 µg/mL IC50 DPPH) of the maqui leaf powder due to its high content of total polyphenols (148.76 mg GAE/g), mainly characterized by having great amounts of hydroxybenzoic acids (82.5 mg GAE/g), flavonoids (7.1 mg QE/g), and hydroxycinnamic acids (3.7 mg CAE/g). Although minimal variations were observed in some individual fatty acids, and despite the trend to decrease MUFA and increase SFA with the maqui leaf powder addition, these differences were minimal and, according to the nutritional indices results, without any influence on the nutritional quality of the beef patties. The organoleptic analysis showed that the addition of maqui leaf powders did not affect the general acceptability of the new formulations. This study reports for the first time the substitution of synthetic antioxidants with Aristotelia chilensis leaves extract. Based on the results, it can be concluded that this ingredient can be used as an alternative for the production of raw meat products with clean labels.

High-pressure processing of fish and shellfish products: Safety, quality, and research prospects

Seafood products have been one of the main drivers behind the popularity of high-pressure processing (HPP) in the food industry owing to a high demand for fresh ready-to-eat seafood products and food safety. This review provides an overview of the advanced knowledge available on the use of HPP for production of wholesome and highly nutritive clean label fish and shellfish products. Out of 653 explored items, 65 articles published during 2016-2021 were used. Analysis of the literature showed that most of the earlier work evaluated the HPP effect on physicochemical and sensorial properties, and limited information is available on nutritional aspects. HPP has several applications in the seafood industry. Application of HPP (400-600 MPa) eliminates common seafood pathogens, such as Vibrio and Listeria spp., and slows the growth of spoilage microorganisms. Use of cold water as a pressure medium induces minimal changes in sensory and nutritional properties and helps in the development of clean label seafood products. This technology (200-350 MPa) is also useful to shuck oysters, lobsters, crabs, mussels, clams, and scallops to increase recovery of the edible meat. High-pressure helps to preserve organoleptic and functional properties for an extended time during refrigerated storage. Overall, HPP helps seafood manufacturers to maintain a balance between safety, quality, processing efficiency, and regulatory compliance. Further research is required to understand the mechanisms of pressure-induced modifications and clean label strategies to minimize these modifications.

BMI, Alcohol Consumption and Gut Microbiome Species Richness Are Related to Structural and Functional Neurological Abnormalities

Background: The incidence of neurological diseases is increasing throughout the world. The aim of the present study was to identify nutrition and microbiome factors related to structural and functional neurological abnormalities to optimize future preventive strategies. Methods: Two hundred thirty-eight patients suffering from (1) structural (neurodegeneration) or (2) functional (epilepsy) neurological abnormalities or (3) chronic pain (migraine) and 612 healthy control subjects were analyzed by validated 12-month food frequency questionnaire (FFQ) and 16S rRNA microbiome sequencing (from stool samples). A binomial logistic regression model was applied for risk calculation and functional pathway analysis to show which functional pathway could discriminate cases and healthy controls. Results: Detailed analysis of more than 60 macro- and micronutrients revealed no distinct significant difference between cases and controls, whereas BMI, insulin resistance and metabolic inflammation in addition to alcohol consumption were major drivers of an overall neurological disease risk. The gut microbiome analysis showed decreased alpha diversity (Shannon index: p = 9.1× 10⁻⁷) and species richness (p = 1.2 × 10⁻⁸) in the case group as well as significant differences in beta diversity between cases and controls (Bray–Curtis: p = 9.99 × 10⁻⁴; Jaccard: p = 9.99 × 10⁻⁴). The Shannon index showed a beneficial effect (OR = 0.59 (95%-CI (0.40, 0.87); p = 8 × 10⁻³). Cases were clearly discriminated from healthy controls by environmental information processing, signal transduction, two component system and membrane transport as significantly different functional pathways. Conclusions: In conclusion, our data indicate that an overall healthy lifestyle, in contrast to supplementation of single micro- or macronutrients, is most likely to reduce overall neurological abnormality risk and that the gut microbiome is an interesting target to develop novel preventive strategies.

Associations between the Mediterranean Diet Pattern and Weight Status and Cognitive Development in Preschool Children

Cognitive dysfunctions are a global health concern. Early-life diet and weight status may contribute to children’s cognitive development. For this reason, we explored the associations between habitual food consumption, body mass index (BMI) and cognitive outcomes in 54 preschool children belonging to the Pisa birth Cohort (PISAC). We estimated groups of foods, nutrients and calorie intakes through a food frequency questionnaire (FFQ) and Italian national databases. Then, we adopted the Mediterranean diet (MD) score to assess relative MD adherence. Cognition was examined using the Griffiths Mental Development Scales-Extended Revised (GMDS-ER). We found that higher, compared to low and moderate, adherence to MD was associated with higher performance scores. Furthermore, white meat consumption was positively related to BMI, and BMI (age–gender specific, z-scores) categories were negatively related to practical reasoning scores. All associations were independent of maternal IQ estimates, parents’ socioeconomic status, exclusive/non-exclusive breastfeeding, actual age at cognitive assessment and gender. In conclusion, in preschool children, very high adherence to MD seemed protective, whereas BMI (reinforced by the intake of white meat) was negatively associated with cognition.

Associations of Body Mass Index-Metabolic Phenotypes with Cognitive Decline in Parkinson's Disease

BACKGROUND

Growing evidence suggests important effects of body mass index (BMI) and metabolic status on neurodegenerative diseases. However, the roles of BMI and metabolic status on cognitive outcomes in Parkinson's disease (PD) may vary and are yet to be determined.

METHODS

In total, 139 PD patients from the whole PD cohort in Parkinson's Progression Markers Initiative database underwent complete laboratory measurements, demographic and anthropometric parameters at baseline, and were enrolled in this study. Further, they were categorized into 4 different BMI-metabolic status phenotypes using Adult Treatment Panel-III criteria. Motor and cognition scales at baseline and longitudinal changes after a 48-month follow-up were compared among the 4 groups. Repeated-measure linear mixed models were performed to compare PD-related biomarkers among BMI-metabolic status phenotypes across time.

RESULTS

We found that PD patients in the metabolically unhealthy normal weight group showed more cognitive decline in global cognition and visuospatial perception after a 48-month follow-up than those in the other 3 groups (p < 0.05). No difference was found in motor scales among different BMI-metabolic status phenotypes. Finally, compared to the metabolically healthy normal weight group, the metabolically healthy obesity group had lower CSF Aβ42 and serum neurofilament levels in repeated-measure linear mixed models adjusting for age, gender, APOE e4 carrier status, and years of education (p = 0.031 and 0.046, respectively).

CONCLUSION

The MUNW phenotype was associated with a rapid cognitive decline in PD.

Relationship between Innate Immune Response Toll-Like Receptor 4 (TLR-4) and the Pathophysiological Process of Obesity Cardiomyopathy

Fundamento

A obesidade é uma condição inflamatória crônica de baixo grau relacionada a distúrbios cardíacos. No entanto, o mecanismo responsável pela inflamação cardíaca relacionada à obesidade não é claro. O receptor do tipo toll 4 (TLR-4) pertence a um receptor da família das transmembranas, responsável pela resposta imune, cuja ativação estimula a produção de citocinas pró-inflamatórias.

Objetivo

Testar se a ativação do receptor TLR-4 participa do processo de cardiomiopatia da obesidade, devido à produção de citocinas por meio da ativação do NF-ĸB.

Métodos

Ratos Wistar machos foram randomizados em dois grupos: o grupo controle (C, n = 8 animais) que recebeu dieta padrão/água e o grupo obeso (OB, n = 8 animais) que foi alimentado com dieta rica em açúcar e gordura e água mais 25% de sacarose por 30 semanas. Análise nutricional: peso corporal, índice de adiposidade, alimentos, água e ingestão calórica. Análise de distúrbios relacionados à obesidade: glicose plasmática, ácido úrico e triglicerídeos, HOMA-IR, pressão arterial sistólica, TNF-α no tecido adiposo. A análise cardíaca incluiu: expressão das proteínas TLR-4 e NF-ĸB, níveis de TNF-α e IL-6. Comparação pelo teste t de Student não pareado ou teste de Mann-Whitney com um valor de p <0,05 como estatisticamente significativo.

Resultados

O grupo OB apresentou obesidade, glicose elevada, triglicerídeos, ácido úrico, HOMA, pressão arterial sistólica e TNF-α no tecido adiposo. O grupo OB apresentou remodelação cardíaca e disfunção diastólica. A expressão de TLR-4 e NF-ĸB e os níveis de citocinas foram maiores em OB.

Conclusão

Nossos achados concluem que, em uma condição obesogênica, a inflamação derivada da ativação do TLR-4 cardíaco pode ser um mecanismo capaz de levar à remodelação e disfunção cardíaca.

Effect of processing technologies on the digestibility of egg proteins

Egg and egg products are a rich source of highly bioavailable animal proteins. Several processing technologies can affect the structural and functional properties of these proteins differently and can influence their fate inside the gastrointestinal tract. The present review examines some of the processing technologies for improving egg protein digestibility and discusses how different processing conditions affect the digestibility of egg proteins under gastrointestinal digestion environments. To provide up-to-date information, most of the studies included in this review have been published in the last 5 years on different aspects of egg protein digestibility. Digestibility of egg proteins can be improved by employing some processing technologies that are able to improve the susceptibility of egg proteins to gastrointestinal proteases. Processing technologies, such as pulsed electric field, high-pressure, and ultrasound, can induce conformational and microstructural changes that lead to unfolding of the polypeptides and expose active sites for further interactions. These changes can enhance the accessibility of digestive proteases to cleavage sites. Some of these technologies may inactivate some egg proteins that are enzyme inhibitors, such as trypsin inhibitors. The underlying mechanisms of how different technologies mediate the egg protein digestibility have been discussed in detail. The proteolysis patterns and digestibility of the processed egg proteins are not always predictable and depends on the processing conditions. Empirical input is required to tailor the optimization of processing conditions for favorable effects on protein digestibility.

Thermal processing implications on the digestibility of meat, fish and seafood proteins

Thermal processing is an inevitable part of the processing and preparation of meat and meat products for human consumption. However, thermal processing techniques, both commercial and domestic, induce modifications in muscle proteins which can have implications for their digestibility. The nutritive value of muscle proteins is closely related to their digestibility in the gastrointestinal tract and is determined by the end products that it presents in the assimilable form (amino acids and small peptides) for the absorption. The present review examines how different thermal processing techniques, such as sous-vide, microwave, stewing, roasting, boiling, frying, grilling, and steam cooking, affect the digestibility of muscle proteins in the gastrointestinal tract. By altering the functional and structural properties of muscle proteins, thermal processing has the potential to influence the digestibility negatively or positively, depending on the processing conditions. Thermal processes such as sous-vide can induce favourable changes, such as partial unfolding or exposure of cleavage sites, in muscle proteins and improve their digestibility whereas processes such as stewing and roasting can induce unfavourable changes, such as protein aggregation, severe oxidation, cross linking or increased disulfide (S-S) content and decrease the susceptibility of proteins during gastrointestinal digestion. The review examines how the underlying mechanisms of different processing conditions can be translated into higher or lower protein digestibility in detail. This review expands the current understanding of muscle protein digestion and generates knowledge that will be indispensable for optimizing the digestibility of thermally processed muscle foods for maximum nutritional benefits and optimal meal planning.

Lifestyle-dependent microglial plasticity: training the brain guardians

Lifestyle is one of the most powerful instruments shaping mankind; the lifestyle includes many aspects of interactions with the environment, from nourishment and education to physical activity and quality of sleep. All these factors taken in complex affect neuroplasticity and define brain performance and cognitive longevity. In particular, physical exercise, exposure to enriched environment and dieting act through complex modifications of microglial cells, which change their phenotype and modulate their functional activity thus translating lifestyle events into remodelling of brain homoeostasis and reshaping neural networks ultimately enhancing neuroprotection and cognitive longevity.

Evidence of association between obesity and lower cerebral myelin content in cognitively unimpaired adults

BACKGROUND

Myelin loss is a central feature of several neurodegenerative diseases, including Alzheimer's disease (AD). In animal studies, a link has been established between obesity and impairment of oligodendrocyte maturation, the cells that produce and maintain myelin. Although clinical magnetic resonance imaging (MRI) studies have revealed microstructural alterations of cerebral white matter tissue in subjects with obesity, no specific myelin vs. obesity correlation studies have been performed in humans using a direct myelin content metric.

OBJECTIVES

To assess the association between obesity and myelin integrity in cerebral white matter using advanced MRI methodology for myelin content imaging.

METHODS

Studies were performed in the clinical unit of the National Institute on Aging on a cohort of 119 cognitively unimpaired adults. Using advanced MRI methodology, we measured whole-brain myelin water fraction (MWF), a marker of myelin content. Automated brain mapping algorithms and statistical models were used to evaluate the relationships between MWF and obesity, measured using the body mass index (BMI) or waist circumference (WC), in various white matter brain regions.

RESULTS

MWF was negatively associated with BMI or WC in all brain regions evaluated. These associations, adjusted for sex, ethnicity, and age, were statistically significant in most brain regions examined (p < 0.05), with higher BMI or WC corresponding to lower myelin content. Finally, in agreement with previous work, MWF exhibited a quadratic, inverted U-shaped, association with age; this is attributed to the process of myelination from youth through middle age, followed by demyelination afterward.

CONCLUSIONS

These findings suggest that obesity was significantly associated with white matter integrity, and in particular myelin content. We expect that this work will lay the foundation for further investigations to clarify the nature of myelin damage in neurodegeneration, including AD, and the effect of lifestyle factors such as diet and physical activity on myelination.

Structural Brain Changes Associated with Overweight and Obesity

Obesity is a global health problem with a broad set of comorbidities, such as malnutrition, metabolic syndrome, diabetes, systemic hypertension, heart failure, and kidney failure. This review describes recent findings of neuroimaging and two studies of cell density regarding the roles of overnutrition-induced hypothalamic inflammation in neurodegeneration. These studies provided consistent evidence of smaller cortical thickness or reduction in the gray matter volume in people with overweight and obesity; however, the investigated brain regions varied across the studies. In general, bilateral frontal and temporal areas, basal nuclei, and cerebellum are more commonly involved. Mechanisms of volume reduction are unknown, and neuroinflammation caused by obesity is likely to induce neuronal loss. Adipocytes, macrophages of the adipose tissue, and gut dysbiosis in overweight and obese individuals result in the secretion of the cytokines and chemokines that cross the blood-brain barrier and may stimulate microglia, which in turn also release proinflammatory cytokines. This leads to chronic low-grade neuroinflammation and may be an important factor for apoptotic signaling and neuronal death. Additionally, significant microangiopathy observed in rat models may be another important mechanism of induction of apoptosis. Neuroinflammation in neurodegenerative diseases (such as Alzheimer's and Parkinson's diseases) may be similar to that in metabolic diseases induced by malnutrition. Poor cognitive performance, mainly in executive functions, in individuals with obesity is also discussed. This review highlights the neuroinflammatory and neurodegenerative mechanisms linked to obesity and emphasizes the importance of developing effective prevention and treatment intervention strategies for overweight and obese individuals.

Brown adipose tissue-derived exosomes mitigate the metabolic syndrome in high fat diet mice

The ever-increasing incidence of obesity and related disorders impose serious challenges on public health worldwide. Brown adipose tissue (BAT) has strong capacity for promoting energy expenditure and has shown great potential in treating obesity. Exosomes are nanovesicles that share the characteristics of their donor cells. Whether BAT derived exosomes (BAT-Exos) might exert similar metabolic benefits on obesity is worthy of investigation. Methods: Obese mice were established by high-fat-diet (HFD) feeding and were treated with Seum-Exos or BAT-Exos isolated from young healthy mice. Blood glucose, glucose tolerance and blood lipids were tested in mice with indicated treatments. Histology examinations were performed on adipose tissue, liver and heart by HE staining and/or Oil Red O staining. Echocardiography was performed to evaluate cardiac function of mice. In vivo distribution of exosomes was analyzed by fluorescence labeling and imaging and in vitro effects of exosomes were evaluated by cell metabolism analysis. Protein contents of BAT-Exos were analyzed by mass spectrometry. Results: The results showed that BAT-Exos reduced the body weight, lowered blood glucose and alleviated lipid accumulation in HFD mice independently of food intake. Echocardiography revealed that the abnormal cardiac functions of HFD mice were significantly restored after treatment with BAT-Exos. Cell metabolism analysis showed that treatment with BAT-Exos significantly promoted oxygen consumption in recipient cells. Protein profiling of exosomes demonstrated that BAT-Exos were rich in mitochondria components and involved in catalytic processes. Conclusions: Collectively, our study showed that BAT-Exos significantly mitigated the metabolic syndrome in HFD mice. Detailed elucidation of the reactive molecules and mechanism of action would provide new insights in combating obesity and related disorders.

Refined grains intake in high fat, high protein, low carbohydrate and low energy levels subgroups and higher likelihood of abdominal obesity in Chinese population

The purpose of this study was to investigate the association between refined grains intake and obesity in China. Refined grain intake was considered in relation to energy intake and at varied levels of macronutrient distribution. A cross-sectional study of 6913 participants was conducted using internet-based dietary questionnaire for Chinese (IDQC). The associations and dose-response relationships between refined grains intake and obesity were investigated using multivariable logistic regression analyses and restricted cubic spline (RCS) models. There was a positive association between refined grains intake and abdominal obesity for all participants (forth quartile OR, 1.313; 95% CI, 1.103-1.760; p < .05) and this association persisted in low energy, low carbohydrate, high fat and high protein level subgroups. A range of favourable refined grains intake was 88-116 g/d (3-4 servings/d), which might decrease the likelihood of obesity for Chinese residents. Further prospective studies are needed to confirm these findings.

Effect of inactivated Bifidobacterium longum intake on obese diabetes model mice (TSOD)

Obesity and diabetes have been increasing at an alarming rate worldwide. Studies have shown the futility of chemical drugs in the treatment of obesity and diabetes. Bifidobacterium longum (BL), a common member of the gut microbiota throughout the human lifespan, has been widely reported to play a role in host health and disease. Here, we evaluated the effects of inactivated cells of BL (IBL) on obesity and blood glucose levels in TSOD mice by administering IBL orally for 5 weeks. The treated mice showed a significant decrease of body weight gain, adipose tissue mass and blood glucose levels, as well as a significant reduction in blood glucose during an oral glucose tolerance test. The treatment also resulted in reduced levels of cholesterol, triglycerides, and NEFA. Moreover, serum and urine analysis showed low creatinine levels in IBL-treated mice. These data demonstrate that IBL may have the potential to prevent obesity and diabetes.

Cholinesterase targeting by polyphenols: A therapeutic approach for the treatment of Alzheimer's disease

Alzheimer's disease (AD) is a progressive irreversible neurodegenerative disorder characterized by excessive deposition of β-amyloid (Aβ) oligomers, and neurofibrillary tangles (NFTs), comprising of hyperphosphorylated tau proteins. The cholinergic system has been suggested as the earliest and most affected molecular mechanism that describes AD pathophysiology. Moreover, cholinesterase inhibitors (ChEIs) are the potential class of drugs that can amplify cholinergic activity to improve cognition and global performance and reduce psychiatric and behavioral disturbances. Approximately, 60%-80% of all cases of dementia in the world are patients with AD. In view of the continuous rise of this disease especially in the aged population, there is a dire need to come up with a novel compound and/or mixture that could work against this devastating disease. In this regard, the best is to rely on natural compounds rather than synthetic ones, because natural compounds are easily available, cost-effective, and comparatively less toxic. To serve this purpose, lately, scientific community has started exploring the possibility of using different polyphenols either solitary or in combination that can serve as therapeutics against AD. In the current article, we have summarized the role of various polyphenols, namely quercetin, resveratrol, curcumin, gallocatechins, cinnamic acid, caffeine, and caffeic acid as an inhibitor of cholinesterase for the treatment of AD. We have also tried to uncover the mechanistic insight on the action of these polyphenols against AD pathogenicity.