Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake

The Role of Intermittent Fasting in the Activation of Autophagy Processes in the Context of Cancer Diseases

Intermittent fasting (IF) is a dietary approach that influences key metabolic pathways, including autophagy-a crucial mechanism in maintaining cellular homeostasis. Autophagy plays a dual role in oncogenesis, acting both as a tumor suppressor and a survival mechanism under metabolic stress. IF has shown potential for reducing cancer risk and enhancing therapeutic efficacy by sensitizing tumor cells to chemotherapy and radiotherapy. However, its effects depend heavily on the type and stage of cancer. Potential risks, such as excessive weight loss and malnutrition, require careful evaluation. Further clinical studies are needed to optimize IF protocols as adjuncts to cancer therapy. This review discusses autophagy mechanisms induced by IF, their therapeutic implications in oncology, and the limitations of this dietary strategy.

Intermittent fasting reduces alpha-synuclein pathology and functional decline in a mouse model of Parkinson's disease

Parkinson's disease (PD) is a neurodegenerative disorder characterized by dopaminergic neuron degeneration and α-synuclein (aSyn) accumulation. Environmental factors play a significant role in PD progression, highlighting the potential of non-pharmacological interventions. This study investigates the therapeutic effects of intermittent fasting (IF) in an rAAV-aSyn mouse model of PD. IF, initiated four weeks post-induction of aSyn pathology, improved motor function and reduced dopaminergic neuron and axon terminal degeneration. Additionally, IF preserved dopamine levels and synaptic integrity in the striatum. Mechanistically, IF enhanced autophagic activity, promoting phosphorylated-aSyn clearance and reducing its accumulation in insoluble brain fractions. Transcriptome analysis revealed IF-induced modulation of inflammation-related genes and microglial activation. Validation in primary cultures confirmed that autophagy activation and inflammatory modulators (CCL17, IL-36RN) mitigate aSyn pathology. These findings suggest that IF exerts neuroprotective effects, supporting further exploration of IF and IF-mimicking therapies as potential PD treatments.

Intermittent fasting boosts sexual behavior by limiting the central availability of tryptophan and serotonin

Aging affects reproductive capabilities in males through physiological and behavioral alterations, including endocrine changes and decreased libido. In this study, we investigated the influence of intermittent fasting (IF) on these aging-related declines, using male C57BL/6J mice. Our findings revealed that IF significantly preserved reproductive success in aged mice, not by improving traditional reproductive metrics such as sperm quality or endocrine functions but by enhancing mating behavior. This behavioral improvement was attributed to IF's ability to counter age-dependent increases in serotonergic inhibition, primarily through the decreased supply of the serotonin precursor tryptophan from the periphery to the brain. Our research underscores the potential of dietary interventions like IF in mitigating age-associated declines in male reproductive health and suggests a novel approach to managing conditions related to reduced sexual desire, highlighting the complex interplay between diet, metabolism, and reproductive behavior.

Efficacy of Intermittent Fasting in the Management of Chronic Plaque Psoriasis: A Phase IIb Clinical Trial

Background

Dietary measures have been used as an adjunctive therapy in the management of psoriasis. Intermittent fasting (IF) is an eating pattern in which energy is not consumed for a fixed duration, resulting in metabolic switch from liver-derived glucose to adipose-derived ketones. The data regarding effectiveness of IF in psoriasis are limited.

Aim and Objectives

The aim of this study was to assess efficacy of IF in patients with chronic plaque psoriasis. The primary outcome of the study was change in psoriasis severity as measured by psoriasis area and severity index (PASI) at 28 weeks. The secondary outcome measures were change in metabolic parameters and biomarkers for atherosclerosis in each group.

Patients and Methods

The study was designed as a randomized parallel group trial. Clinical parameters, psoriasis severity, fasting and postprandial blood sugar, lipid profile, high sensitivity C-reactive protein (hsCRP), vascular endothelial growth factor (VEGF), and interleukin 6 (IL-6), were measured using standard methods at baseline, 16 weeks, and 28 weeks. Patients were randomized to receive methotrexate in the dose of 0.3 mg/Kg/week with or without intermittent fasting.

Results

A total of 120 patients were randomized in two groups of 60 each: group 1 (methotrexate) and group 2 (methotrexate and intermittent fasting). The mean age, mean duration of disease, PASI, and dermatology life quality index (DLQI) in group 1 were 45.5 (±12.9) years, 5.06 (±5.5) years, 17.1 (±6.7), and 12.33 (±5), respectively. The mean age, mean duration of disease, PASI, and DLQI in group 2 were and 42.9 (±14.6) years, 6.91 (±6.2) years, 16 (±4.3), and 11.9 (±4.3), respectively. There was no statistically significant difference in baseline parameters in two groups. In both the groups, there was a statistically significant difference in PASI, DLQI, VEGF, and hsCRP from baseline to 16 and 28 weeks. At week 16, 44 (73.3%) patients in group 1 and 47 (78.3%) in group 2 achieved PASI50 (P = 0.8). At week 28, 16 (36%) in group 1 and 27 (54.4%) patients in group 2 maintained PASI50 (P = 0.054). There was a statistically significant weight and waist circumference reduction at 16 weeks and 28 weeks in group 2. There was a statistically significant reduction in VEGF, IL6, and hsCRP at 28 weeks in group 2 as compared to group 1.

Limitations

The small sample size and loss to follow-up are major limitations of the study.

Conclusion

Intermittent fasting using 16: 8 protocol is easy to perform and a safe and effective adjuvant for managing severe chronic plaque psoriasis. It helps in maintaining remission and results in improvement in metabolic parameters and markers of vascular inflammation.

The cyclic metabolic switching theory of intermittent fasting

Intermittent fasting (IF) and ketogenic diets (KDs) have recently attracted much attention in the scientific literature and in popular culture and follow a longer history of exercise and caloric restriction (CR) research. Whereas IF involves cyclic metabolic switching (CMS) between ketogenic and non-ketogenic states, KDs and CR may not. In this Perspective, I postulate that the beneficial effects of IF result from alternating between activation of adaptive cellular stress response pathways during the fasting period, followed by cell growth and plasticity pathways during the feeding period. Thereby, I establish the cyclic metabolic switching (CMS) theory of IF. The health benefits of IF may go beyond those seen with continuous CR or KDs without CMS owing to the unique interplay between the signalling functions of the ketone β-hydroxybutyrate, mitochondrial adaptations, reciprocal activation of autophagy and mTOR pathways, endocrine and paracrine signalling, gut microbiota, and circadian biology. The CMS theory may have important implications for future basic research, clinical trials, development of pharmacological interventions, and healthy lifestyle practices.

Alternate-day fasting enhanced weight loss and metabolic benefits over pair-fed calorie restriction in obese mice

OBJECTIVE

Both alternate-day fasting (ADF) and calorie restriction (CR) are effective weight loss strategies. However, most individuals find it difficult to adhere to CR. Furthermore, CR can induce an excessive loss of not only fat but also muscle mass. This study aimed to compare the effects of ADF and pair-feeding (PF) CR on metabolic pathways underlying obesity in mice with high-fat diet (HFD)-induced obesity.

METHODS

Male C57BL/6N Tac mice (n = 10 per group) were fed an HFD for 8 weeks to establish a diet-induced obesity model. Mice were then continued on the HFD with either alternate-day access to food or PF for the next 8 weeks. We measured body weight, adiposity, plasma biomarkers, and molecular mechanisms involving lipolysis and autophagy.

RESULTS

Both ADF and PF resulted in comparable weight and fat loss. Compared with PF, ADF showed a significant reduction in liver weight and hepatic triglyceride levels. ADF significantly increased plasma ketone body levels and white adipose tissue lipolysis. Compared with PF, ADF tended to activate autophagy elongation and autophagosome formation, which were insignificant.

CONCLUSIONS

These findings indicated that ADF is a promising intervention for metabolic diseases, potentially due to its superior efficacy in promoting ketogenesis and lipolysis compared with PF.

Unveiling the Therapeutic Promise of Epigenetics in Vascular Cognitive Impairment and Vascular Dementia

Vascular dementia (VaD) is a progressive neurodegenerative disease characterized by cognitive decline and memory deficits. Despite its significant prevalence and impact, the pathophysiology of VaD remains poorly understood, and current treatments are limited to symptom management. Emerging evidence highlights the importance of lifestyle-associated risk factors in VaD, emphasizing the role of gene-environment interactions, particularly in the realm of epigenetics. While preclinical studies using animal models have provided valuable insights into epigenetic mechanisms, the translatability of these findings to human clinical settings remains limited, and research into VaD-specific epigenetics is still in its infancy. This review aims to elucidate the intricate interplay between epigenetics and VaD, shedding light on potential therapeutic interventions rooted in epigenetic mechanisms. By synthesizing insights from existing literature, we also discuss the challenges and opportunities in translating preclinical findings into clinically viable treatments, underscoring the need for further research to bridge the gap between animal models and human applications.

DEAD-box RNA helicase DDX-23 mediates dietary restriction induced health span in Caenorhabditis elegans

Dietary restriction (DR) extends lifespan in diverse species, from yeast to mammals. However, its underlying mechanisms are not well understood. In this study, through using the tractable model Caenorhabditis elegans, we show a role for the DEAD-box RNA helicase, DDX-23 (homologous to mammal DDX23) as a regulator of healthspan in response to dietary restriction. Meanwhile, DDX-23 is also required for heat and oxidative stress response in C. elegans. Intriguingly, DDX-23 functions in the germline during adult to regulate dietary restriction-induced longevity. We then find that PHA-4/FOXA acts downstream of DDX-23 to mediate the transcriptional response of SOD-related genes and consequently the lifespan of the animals. Furthermore, we find that the DEAD-box RNA helicase, DDX-23 negatively regulates the healthy lifespan extension by up-regulating the expression of miR-231, and resulting in suppressing the activation of FOXO transcription factor DAF-16. Our work shows a newly discovered for DEAD-box RNA helicase DDX-23 in the regulation of dietary restriction-mediated longevity in C. elegans and reveals the downstream transcriptional regulation mechanisms.

Effects of the periodic fasting-mimicking diet on health, lifespan, and multiple diseases: a narrative review and clinical implications

Dietary restriction and fasting have been recognized for their beneficial effects on health and lifespan and their potential application in managing chronic metabolic diseases. However, long-term adherence to strict dietary restrictions and prolonged fasting poses challenges for most individuals and may lead to unhealthy rebound eating habits, negatively affecting overall health. As a result, a periodic fasting-mimicking diet (PFMD), involving cycles of fasting for 2 or more days while ensuring basic nutritional needs are met within a restricted caloric intake, has gained widespread acceptance. Current research indicates that a PFMD can promote stem cell regeneration, suppress inflammation, extend the health span of rodents, and improve metabolic health, among other effects. In various disease populations such as patients with diabetes, cancer, multiple sclerosis, and Alzheimer's disease, a PFMD has shown efficacy in alleviating disease symptoms and improving relevant markers. After conducting an extensive analysis of available research on the PFMD, it is evident that its advantages and potential applications are comparable to other fasting methods. Consequently, it is proposed in this review that a PFMD has the potential to fully replace water-only or very-low-energy fasting regimens and holds promise for application across multiple diseases.

Intermittent fasting triggers interorgan communication to suppress hair follicle regeneration

Intermittent fasting has gained global popularity for its potential health benefits, although its impact on somatic stem cells and tissue biology remains elusive. Here, we report that commonly used intermittent fasting regimens inhibit hair follicle regeneration by selectively inducing apoptosis in activated hair follicle stem cells (HFSCs). This effect is independent of calorie reduction, circadian rhythm alterations, or the mTORC1 cellular nutrient-sensing mechanism. Instead, fasting activates crosstalk between adrenal glands and dermal adipocytes in the skin, triggering the rapid release of free fatty acids into the niche, which in turn disrupts the normal metabolism of HFSCs and elevates their cellular reactive oxygen species levels, causing oxidative damage and apoptosis. A randomized clinical trial (NCT05800730) indicates that intermittent fasting inhibits human hair growth. Our study uncovers an inhibitory effect of intermittent fasting on tissue regeneration and identifies interorgan communication that eliminates activated HFSCs and halts tissue regeneration during periods of unstable nutrient supply.

Repeated fasting events sensitize enhancers, transcription factor activity and gene expression to support augmented ketogenesis

Mammals withstand frequent and prolonged fasting periods due to hepatic production of glucose and ketone bodies. Because the fasting response is transcriptionally regulated, we asked whether enhancer dynamics impose a transcriptional program during recurrent fasting and whether this generates effects distinct from a single fasting bout. We found that mice undergoing alternate-day fasting (ADF) respond profoundly differently to a following fasting bout compared to mice first experiencing fasting. Hundreds of genes enabling ketogenesis are 'sensitized' (i.e. induced more strongly by fasting following ADF). Liver enhancers regulating these genes are also sensitized and harbor increased binding of PPARα, the main ketogenic transcription factor. ADF leads to augmented ketogenesis compared to a single fasting bout in wild-type, but not hepatocyte-specific PPARα-deficient mice. Thus, we found that past fasting events are 'remembered' in hepatocytes, sensitizing their enhancers to the next fasting bout and augment ketogenesis. Our findings shed light on transcriptional regulation mediating adaptation to repeated signals.

Does Fasting and High-Fatty Diet Effect Ossseointegration: An Experimental Study

BACKGROUND

Hyperlipidemia caused by a high-fat diet (HFD) has many adverse effects on the cardiovascular system, including vascular problems. In addition, a high-fat diet has significant adverse effects on bone health.

AIM

This study aimed to investigate the levels of bone-implant connection in rats subjected to fasting and a high-fatty diet.

METHODS

This study utilized a sample size of 28 female Spraque-Dawley rats. The rats were divided into four groups, with 7 rats in each group; the control group on a normal diet (Group 1) (n = 7), the fasted group (Group 2) (n = 7), the high-fatty diet (HFD) group (Group 3) (n = 7), and the fasted and high-fat diet (Group 4) (n = 7). Machined surfaced titanium implants with a diameter of 2.5 mm and a length of 4 mm were placed in the right tibia bones of the subjects. All rats that continued the administered diet for 12 weeks were sacrificed at the end of the experimental period. The implants and the surrounding bone tissue were surgically removed and subjected to biomechanical analysis to assess bone-implant osteintegration.

RESULTS

There was no statistically significant difference in bone-implant osteointegration (P > 0,05) between the rats in the control group and the other three groups.

CONCLUSION

This study determined that fasting or maintaining a high-fat diet does not adversely affect the bone-implant connection in rats' tibias.

Intermittent fasting shifts the diurnal transcriptome atlas of transcription factors

Intermittent fasting remains a safe and effective strategy to ameliorate various age-related diseases, but its specific mechanisms are not fully understood. Considering that transcription factors (TFs) determine the response to environmental signals, here, we profiled the diurnal expression of 600 samples across four metabolic tissues sampled every 4 over 24 h from mice placed on five different feeding regimens to provide an atlas of TFs in biological space, time, and feeding regimen. Results showed that 1218 TFs exhibited tissue-specific and temporal expression profiles in ad libitum mice, of which 974 displayed significant oscillations at least in one tissue. Intermittent fasting triggered more than 90% (1161 in 1234) of TFs to oscillate somewhere in the body and repartitioned their tissue-specific expression. A single round of fasting generally promoted TF expression, especially in skeletal muscle and adipose tissues, while intermittent fasting mainly suppressed TF expression. Intermittent fasting down-regulated aging pathway and upregulated the pathway responsible for the inhibition of mammalian target of rapamycin (mTOR). Intermittent fasting shifts the diurnal transcriptome atlas of TFs, and mTOR inhibition may orchestrate intermittent fasting-induced health improvements. This atlas offers a reference and resource to understand how TFs and intermittent fasting may contribute to diurnal rhythm oscillation and bring about specific health benefits.

Comparative Impact of Alternate-Day Fasting and Time-Restricted Feeding on Placental Function and Fetal Development in Maternal Obesity

BACKGROUND

Maternal obesity detrimentally affects placental function and fetal development. Both alternate-day fasting (ADF) and time-restricted feeding (TRF) are dietary interventions that can improve metabolic health, yet their comparative effects on placental function and fetal development remain unexplored.

OBJECTIVES

This study aims to investigate the effects of ADF and TRF on placental function and fetal development during maternal consumption of a high-fat diet (HFD).

METHODS

One hundred 8-week-old female mice were assigned to one of four dietary regimens: (1) normal diet with ad libitum feeding (NA); (2) HFD with ad libitum feeding (HA); (3) HFD with ADF (HI); and (4) HFD with TRF (HT), administered both before and during pregnancy. On gestational day 18.5, serum and placental samples were collected from both mothers and fetuses to examine placental function and fetal development.

RESULTS

During gestation, both ADF and TRF substantially alleviated the metabolic impairments caused by an HFD in obese maternal mice. TRF mice demonstrated enhanced placental nutrient transport and fetal development, associated with reduced endoplasmic reticulum (ER) stress and inflammatory responses. In contrast, ADF markedly intensified placental stress and inflammatory responses, diminished placental nutrient transport efficiency, and consequently induced fetal growth restriction.

CONCLUSIONS

Both ADF and TRF during pregnancy significantly mitigated metabolic impairments in obese dams on an HFD. TRF mice demonstrated enhanced placental nutrient transport and fetal development, associated with reduced endoplasmic reticulum (ER) stress and inflammatory responses. In contrast, ADF markedly intensified placental stress and inflammatory responses, diminished placental nutrient transport efficiency, and consequently induced fetal growth restriction.

Dietary Restriction and Lipid Metabolism: Unveiling Pathways to Extended Healthspan

Dietary restriction (DR) has been reported to be a significant intervention that influences lipid metabolism and potentially modulates the aging process in a wide range of organisms. Lipid metabolism plays a pivotal role in the regulation of aging and longevity. In this review, we summarize studies on the significant role of lipid metabolism in aging in relation to DR. As a potent intervention to slow down aging, DR has demonstrated promising effects on lipid metabolism, influencing the aging processes across various species. The current review focuses on the relationships among DR-related molecular signaling proteins such as the sirtuins, signaling pathways such as the target of rapamycin and the insulin/insulin-like growth factor (IGF)-1, lipid metabolism, and aging. Furthermore, the review presents research results on diet-associated changes in cell membrane lipids and alterations in lipid metabolism caused by commensal bacteria, highlighting the importance of lipid metabolism in aging. Overall, the review explores the interplay between diet, lipid metabolism, and aging, while presenting untapped areas for further understanding of the aging process.

The catabolic - anabolic cycling hormesis model of health and resilience

A major goal of aging research is to identify ways of extending productive and disease-free lifespans. Here we present the catabolic - anabolic cycling hormesis (CACH) model for optimizing health. The CACH model is based on the concept that cells and organ systems respond to catabolic challenges in ways that bolster their resilience and that an anabolic recovery period is required to effectuate the benefits of the catabolic challenge. As two prominent real-world examples we highlight the literature on the molecular and cellular mechanisms by which physical exercise and intermittent fasting bolster cellular and organismal performance and resilience, and suppress disease processes. Over periods of weeks and months the CACH of exercise and fasting promote optimal health. The hormesis concept is integral to the CACH model and predicts an upper limit to the beneficial effects of catabolic - anabolic cycling that reflects a limit of biological plasticity. This paper extends the hormesis model of health by proposing that 1) it is comprised of two complementary phases: catabolic (adaptive stress responses and conservation of resources) and anabolic (growth and plasticity) and, 2) that CACH is metabolically integrated, quantitatively flexible and dynamically regulated. This model has important implications for future basic and translational research in the fields of aging and related disease processes.

The dietary exposome: a brief history of diet, longevity, and age-related health in rodents

It has been recognized for over a century that feeding animals less food than they would normally eat increases lifespan and leads to broad-spectrum improvements in age-related health. A significant number of studies have subsequently shown that restricting total protein, branched chain amino acids or individual amino acids in the diet, as well as ketogenic diets, can elicit similar effects. In addition, it is becoming clear that fasting protocols, such as time-restricted-feeding or every-other-day feeding, without changes in overall energy intake can also profoundly affect rodent longevity and late-life health. In this review, I will provide a historical perspective on various dietary interventions that modulate ageing in rodents and discuss how this understanding of the dietary exposome may help identify future strategies to maintain late-life health and wellbeing in humans.

Intermittent Fasting-Induced Orm2 Promotes Adipose Browning via the GP130/IL23R-p38 Cascade

Intermittent fasting (IF) plays a critical role in mitigating obesity, yet the precise biological mechanisms require further elucidation. Here Orosomucoid 2 (Orm2) is identified as an IF-induced hepatokine that stimulates adipose browning. IF induced Orm2 expression and secretion from the liver through peroxisome proliferator-activated receptor alpha (PPARα). In adipose tissue, Orm2 bound to glycoprotein 130/interleukin 23 receptor (GP130/IL23R) and promoted adipose browning through the activation of p38 mitogen-activated protein kinases (p38-MAPK). In obese mice, Orm2 led to a significant induction of adipose tissue browning and subsequent weight loss, an effect that is not replicated by a mutant variant of Orm2 deficient in GP130/IL23R binding capability. Crucially, genetic association studies in humans identified an obesity-associated Orm2 variant (D178E), which shows decreased GP130/IL23R binding and impaired browning capacity in mice. Overall, the research identifies Orm2 as a promising therapeutic target for obesity, mediating adipose browning through the GP130/IL23R-p38 signalling pathway.

Intermittent fasting alerts neurotransmitters and oxidant/antioxidant status in the brain of rats

Several recent studies have attempted to understand how fasting has benefits for body health, especially the nervous system. To evaluate the impact of intermittent fasting on body weight, brain neurotransmitters, brain oxidative stress, and brain-derived neurotrophic factor (BDNF) in several areas of the brain, this study was conducted in rats. Thirty male Wistar rats were randomly divided into two groups. Group 1 (15 rats) served as the control and group 2 (15 rats) underwent intermittent fasting (IF; 24 h) for 1, 7, or 15 days. The findings demonstrated that intermittent fasting significantly reduced body weight. In this sense, brain monoamines and amino acids, namely dopamine, glutamate, aspartate, and oxidative stress markers (malondialdehyde and nitric oxide), decreased significantly after 1 day of IF. However, norepinephrine, serotonin, gamma-amino butyric acid, and glycine increased significantly. Additionally, glutathione levels were markedly elevated in IF. Surprisingly, the neuromodulatory effect of intermittent fasting fluctuates depending on the IF period. To support this fluctuation, BDNF levels increased after 1 day in the hippocampus and decreased after 15 days of intermittent fasting in all areas of the brain tested. In conclusion, our results show that intermittent fasting has beneficial influences on the brain; however, prolonged intermittent fasting can also induce some unfavorable physiological outcomes that prevent optimal neurological function.

Intermittent fasting alleviates postoperative cognitive dysfunction by reducing neuroinflammation in aged mice

Elderly individuals undergoing surgical procedures are often confronted with the peril of experiencing postoperative cognitive dysfunction (POCD). Prior research has demonstrated the exacerbating effect of sevoflurane anesthesia on neuroinflammation, which can further deteriorate the condition of POCD in elderly patients. Intermittent fasting (IF) restricts food consumption to a specific time window and has been demonstrated to ameliorate cognitive dysfunction induced by neuropathic inflammation. We subjected 18-month-old male mice to 16 hours of fasting and 8 hours of unrestricted eating over a 24-hour period for 0, 1, 2, and 4 weeks, followed by abdominal exploration under sevoflurane anesthesia. In this study, we aim to explore the potential impact of IF on postoperative cognitive function in aged mice undergoing sevoflurane surgery through the preoperative implementation of IF measures. The findings indicate two weeks of IF leads to a significant enhancement of learning and memory capabilities in mice following surgery. The cognitive performance, as determined by the novel object recognition and Morris water maze tests, as well as the synaptic plasticity, as measured by in vivo electrophysiological recordings, has demonstrated marked improvements. Furthermore, the administration of IF markedly enhances the expression of synaptic-associated proteins in hippocampal neurons, concomitant with a decreasing expression of pro-inflammatory factors and a reduced density of microglial cells within the hippocampal brain region. To summarize, the results of this study indicate that IF may mitigate inflammation in the hippocampal area of the brain. Furthermore, IF appears to provide a safeguard against cognitive impairment and synaptic plasticity impairment brought on by sevoflurane anesthesia.

Circadian-Dependent Intermittent Fasting Influences Ischemic Tolerance and Dendritic Spine Remodeling

BACKGROUND

Preconditioning by intermittent fasting is linked to improved cognition and motor function, and enhanced recovery after stroke. Although the duration of fasting was shown to elicit different levels of neuroprotection after ischemic stroke, the impact of time of fasting with respect to the circadian cycles remains unexplored.

METHODS

Cohorts of mice were subjected to a daily 16-hour fast, either during the dark phase (active-phase intermittent fasting) or the light phase (inactive-phase intermittent fasting) or were fed ad libitum. Following a 6-week dietary regimen, mice were subjected to transient focal cerebral ischemia and underwent behavioral functional assessment. Brain samples were collected for RNA sequencing and histopathologic analyses.

RESULTS

Active-phase intermittent fasting cohort exhibited better poststroke motor and cognitive recovery as well as reduced infarction, in contrast to inactive-phase intermittent fasting cohort, when compared with ad libitum cohort. In addition, protection of dendritic spine density/morphology and increased expression of postsynaptic density protein-95 were observed in the active-phase intermittent fasting.

CONCLUSIONS

These findings indicate that the time of daily fasting is an important factor in inducing ischemic tolerance by intermittent fasting.

Resistance and Resilience to Alzheimer's Disease

Dementia is a significant public health crisis; the most common underlying cause of age-related cognitive decline and dementia is Alzheimer's disease neuropathologic change (ADNC). As such, there is an urgent need to identify novel therapeutic targets for the treatment and prevention of the underlying pathologic processes that contribute to the development of AD dementia. Although age is the top risk factor for dementia in general and AD specifically, these are not inevitable consequences of advanced age. Some individuals are able to live to advanced age without accumulating significant pathology (resistance to ADNC), whereas others are able to maintain cognitive function despite the presence of significant pathology (resilience to ADNC). Understanding mechanisms of resistance and resilience will inform therapeutic strategies to promote these processes to prevent or delay AD dementia. This article will highlight what is currently known about resistance and resilience to AD, including our current understanding of possible underlying mechanisms that may lead to candidate preventive and treatment interventions for this devastating neurodegenerative disease.

Risks and Benefits of Intermittent Fasting for the Aging Cardiovascular System

Population aging and the associated increase in cardiovascular disease rates pose serious threats to global public health. Different forms of fasting have become an increasingly attractive strategy to directly address aging and potentially limit or delay the onset of cardiovascular diseases. A growing number of experimental studies and clinical trials indicate that the amount and timing of food intake as well as the daily time window during which food is consumed, are crucial determinants of cardiovascular health. Indeed, intermittent fasting counteracts the molecular hallmarks of cardiovascular aging and promotes different aspects of cardiometabolic health, including blood pressure and glycemic control, as well as body weight reduction. In this report, we summarize current evidence from randomized clinical trials of intermittent fasting on body weight and composition as well as cardiovascular and metabolic risk factors. Moreover, we critically discuss the preventive and therapeutic potential of intermittent fasting, but also possible detrimental effects in the context of cardiovascular aging and related disease. We delve into the physiological mechanisms through which intermittent fasting might improve cardiovascular health, and raise important factors to consider in the design of clinical trials on the efficacy of intermittent fasting to reduce major adverse cardiovascular events among aged individuals at high risk of cardiovascular disease. We conclude that despite growing evidence and interest among the lay and scientific communities in the cardiovascular health-improving effects of intermittent fasting, further research efforts and appropriate caution are warranted before broadly implementing intermittent fasting regimens, especially in elderly persons.

Insulin resistance as the molecular link between diabetes and Alzheimer's disease

Diabetes mellitus (DM) and Alzheimer's disease (AD) are two major health concerns that have seen a rising prevalence worldwide. Recent studies have indicated a possible link between DM and an increased risk of developing AD. Insulin, while primarily known for its role in regulating blood sugar, also plays a vital role in protecting brain functions. Insulin resistance (IR), especially prevalent in type 2 diabetes, is believed to play a significant role in AD's development. When insulin signalling becomes dysfunctional, it can negatively affect various brain functions, making individuals more susceptible to AD's defining features, such as the buildup of beta-amyloid plaques and tau protein tangles. Emerging research suggests that addressing insulin-related issues might help reduce or even reverse the brain changes linked to AD. This review aims to explore the rela-tionship between DM and AD, with a focus on the role of IR. It also explores the molecular mechanisms by which IR might lead to brain changes and assesses current treatments that target IR. Understanding IR's role in the connection between DM and AD offers new possibilities for treatments and highlights the importance of continued research in this interdisciplinary field.

Integration of a fasting-mimicking diet programme in primary care for type 2 diabetes reduces the need for medication and improves glycaemic control: a 12-month randomised controlled trial

AIMS/HYPOTHESIS

The aim of this study was to evaluate the impact on metabolic control of periodic use of a 5-day fasting-mimicking diet (FMD) programme as an adjunct to usual care in people with type 2 diabetes under regular primary care surveillance.

METHODS

In this randomised, controlled, assessor-blinded trial, people with type 2 diabetes using metformin as the only glucose-lowering drug and/or diet for glycaemic control were randomised to receive 5-day cycles of an FMD monthly as an adjunct to regular care by their general practitioner or to receive regular care only. The primary outcomes were changes in glucose-lowering medication (as reflected by the medication effect score) and HbA1c levels after 12 months. Moreover, changes in use of glucose-lowering medication and/or HbA1c levels in individual participants were combined to yield a clinically relevant outcome measure ('glycaemic management'), which was categorised as improved, stable or deteriorated after 1 year of follow-up. Several secondary outcome measures were also examined, including changes in body weight.

RESULTS

One hundred individuals with type 2 diabetes, age 18-75 years, BMI ≥27 kg/m2, were randomised to the FMD group (n=51) or the control group (n=49). Eight FMD participants and ten control participants were lost to follow-up. Intention-to-treat analyses, using linear mixed models, revealed adjusted estimated treatment effects for the medication effect score (-0.3; 95% CI -0.4, -0.2; p<0.001), HbA1c (-3.2 mmol/mol; 95% CI -6.2, -0.2 and -0.3%; 95% CI -0.6, -0.0; p=0.04) and body weight (-3.6 kg; 95% CI -5.2, -2.1; p<0.001) at 12 months. Glycaemic management improved in 53% of participants using FMD vs 8% of control participants, remained stable in 23% vs 33%, and deteriorated in 23% vs 59% (p<0.001).

CONCLUSIONS/INTERPRETATION

Integration of a monthly FMD programme in regular primary care for people with type 2 diabetes who use metformin as the only glucose-lowering drug and/or diet for glycaemic control reduces the need for glucose-lowering medication, improves HbA1c despite the reduction in medication use, and appears to be safe in routine clinical practice.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03811587 FUNDING: The project was co-funded by Health~Holland, Top Sector Life Sciences & Health, the Dutch Diabetes Foundation and L-Nutra.

Intermittent Fasting: Myths, Fakes and Truth on This Dietary Regimen Approach

Intermittent fasting (IF) has been indicated as a valuable alternative to the classical caloric restriction dietary regimen for lowering body weight and preventing obesity-related complications, such as metabolic syndrome and type II diabetes. However, is it effective? In this review article, we analyzed over 50 clinical studies in which IF, conducted by alternate day fasting (ADF) or time-restricted feeding (TRF), was compared with the caloric restriction approach. We evaluated the different roles of IF in treating and preventing human disorders such as metabolic syndrome, type II diabetes, and some types of cancer, as well as the usefulness of IF in reducing body weight and cardiovascular risk factors such as hypertension. Furthermore, we explored the cellular pathways targeted by IF to exert their beneficial effects by activating effector proteins that modulate cell functions and resistance to oxidative stress. In contrast, we investigated concerns regarding human health related to the adoption of IF dietary regimens, highlighting the profound debate surrounding weight loss regimens. We examined and compared several clinical trials to formulate an updated concept regarding IF and its therapeutic potential.

Strategies for Improving Firefighter Health On-Shift: A Review

The fire service suffers from high rates of cardiovascular disease and poor overall health, and firefighters often suffer fatal and non-fatal injuries while on the job. Most fatal injuries result from sudden cardiac death, while non-fatal injuries are to the musculoskeletal system. Previous works suggest a mechanistic link between several health and performance variables and injury risk. In addition, studies have suggested physical activity and nutrition can improve overall health and occupational performance. This review offers practical applications for exercise via feasible training modalities as well as nutritional recommendations that can positively impact performance on the job. Time-efficient training modalities like high-intensity interval training and feasible modalities such as resistance training offer numerous benefits for firefighters. Also, modifying and supplementing the diet and can be advantageous for health and body composition in the fire service. Firefighters have various schedules, making it difficult for planned exercise and eating while on shift. The practical training and nutritional aspects discussed in this review can be implemented on-shift to improve the overall health and performance in firefighters.

Intermittent Fasting-Improved Glucose Homeostasis Is Not Entirely Dependent on Caloric Restriction in db/db Male Mice

Intermittent fasting (IF), which involves prolonged fasting intervals accompanied by caloric restriction (CR), is an effective dietary treatment for obesity and diabetes. Although IF offers many benefits, it is difficult to determine whether these benefits are the consequences of CR. Every-other-day feeding (EODF) is a commonly used IF research model. This study was designed to identify factors, in addition to CR, responsible for the effects of EODF and the possible underlying mechanisms. Diabetic db/db mice were divided into three groups: ad libitum (AL), meal feeding (MF), and EODF. The MF model was used to attain a level of CR comparable to that of EODF, with food distribution evenly divided between 10:00 a.m. and 6:00 p.m., thereby minimizing the fasting interval. EODF yielded greater improvements in glucose homeostasis than MF in db/db mice by reducing fasting glucose levels and enhancing glucose tolerance. However, these effects on glucose metabolism were less pronounced in lean mice. Furthermore, ubiquitination of the liver-specific glucocorticoid (GC) receptor (GR) facilitated its degradation and downregulation of Kruppel-like factor 9 (KLF9), which ultimately suppressed liver gluconeogenesis in diabetic EODF mice. Although GR and KLF9 might mediate the metabolic benefits of EODF, the potential benefits of EODF might be limited by elevated serum GC levels in diabetic EODF mice. Overall, this study suggests that the metabolic benefits of EODF in improving glucose homeostasis are independent of CR, possibly because of the downstream effects of liver-specific GR degradation.

ARTICLE HIGHLIGHTS

Intermittent fasting and longevity: From animal models to implication for humans

In recent years, intermittent fasting (IF) and its numerous modifications have been increasingly suggested as a promising therapy for age-related problems and a non-pharmacological strategy to extend lifespan. Despite the great variability in feeding schedules that we describe in the current work, underlying physiological processes are the same and include a periodic switch from glucose metabolism (generated by glycogenolysis) to fatty acids and fatty acid-derived ketones. Many of the beneficial effects of IF appear to be mediated by optimization of energy utilization. Findings to date from both human and animal experiments indicate that fasting improves physiological function, enhances performance, and slows aging and disease processes. In this review, we discuss some of the remarkable discoveries about the beneficial effects of IF on metabolism, endocrine and cardiovascular systems, cancer prevention, brain health, neurodegeneration and aging. Experimental studies on rodent models and human investigations are summarized to compare the outcomes and underlying mechanisms of IF. Metabolic and cellular responses triggered by IF could help to achieve the aim of preventing disease, and maximizing healthspan and longevity with minimal side effects.

Does diet influence aging? Evidence from animal studies

Nutrition profoundly influences the risk for many age-related diseases. Whether nutrition influences human aging biology directly is less clear. Studies in different animal species indicate that reducing food intake ("caloric restriction" [CR]) can increase lifespan and delay the onset of diseases and the biological hallmarks of aging. Obesity has been described as "accelerated aging" and therefore the lifespan and health benefits generated by CR in both aging and obesity may occur via similar mechanisms. Beyond calorie intake, studies based on nutritional geometry have shown that protein intake and the interaction between dietary protein and carbohydrates influence age-related health and lifespan. Studies where animals are calorically restricted by providing free access to diluted diets have had less impact on lifespan than those studies where animals are given a reduced aliquot of food each day and are fasting between meals. This has drawn attention to the role of fasting in health and aging, and exploration of the health effects of various fasting regimes. Although definitive human clinical trials of nutrition and aging would need to be unfeasibly long and unrealistically controlled, there is good evidence from animal experiments that some nutritional interventions based on CR, manipulating dietary macronutrients, and fasting can influence aging biology and lifespan.

Intermittent fasting protects β-cell identity and function in a type-2 diabetes model

Type 2 diabetes (T2DM) is caused by the interaction of multiple genes and environmental factors. T2DM is characterized by hyperglycemia, insulin secretion deficiency and insulin resistance. Chronic hyperglycemia induces β-cell dysfunction, loss of β-cell mass/identity and β-cell dedifferentiation. Intermittent fasting (IF) a commonly used dietary regimen for weight-loss, also induces metabolic benefits including reduced blood glucose, improved insulin sensitivity, reduced adiposity, inflammation, oxidative-stress and increased fatty-acid oxidation; however, the mechanisms underlying these effects in pancreatic β-cells remain elusive. KK and KKAy, mouse models of polygenic T2DM spontaneously develop hyperglycemia, glucose intolerance, glucosuria, impaired insulin secretion and insulin resistance. To determine the long-term effects of IF on T2DM, 6-weeks old KK and KKAy mice were subjected to IF for 16 weeks. While KKAy mice fed ad-libitum demonstrated severe hyperglycemia (460 mg/dL) at 6 weeks of age, KK mice showed blood glucose levels of 230 mg/dL, but progressively became severely diabetic by 22-weeks. Strikingly, both KK and KKAy mice subjected to IF showed reduced blood glucose and plasma insulin levels, decreased body weight gain, reduced plasma triglycerides and cholesterol, and improved insulin sensitivity. They also demonstrated enhanced expression of the β-cell transcription factors NKX6.1, MAFA and PDX1, and decreased expression of ALDH1a3 suggesting protection from loss of β-cell identity by IF. IF normalized glucose stimulated insulin secretion in islets from KK and KKAy mice, demonstrating improved β-cell function. In addition, hepatic steatosis, gluconeogenesis and inflammation was decreased particularly in KKAy-IF mice, indicating peripheral benefits of IF. These results have important implications as an optional intervention for preservation of β-cell identity and function in T2DM.

Alternate Day Fasting Leads to Improved Post-Stroke Motor Recovery in Mice

BACKGROUND

Caloric restriction promotes neuroplasticity and recovery after neurological injury. In mice, we tested the hypothesis that caloric restriction can act post-stroke to enhance training-associated motor recovery.

METHODS

Mice were trained to perform a skilled prehension task. We then induced a photothrombotic stroke in the caudal forelimb area, after which we retrained animals on the prehension task following an 8-day delay. Mice underwent either ad libitum feeding or alternate day fasting beginning 1-day after stroke and persisting for either 7 days or the entire post-stroke training period until sacrifice.

RESULTS

Prior studies have shown that post-stroke recovery of prehension can occur if animals receive rehabilitative training during an early sensitive period but is incomplete if rehabilitative training is delayed. In contrast, we show complete recovery of prehension, despite a delay in rehabilitative training, when mice underwent alternate day fasting beginning 1-day post-stroke and persisting for either 7 days or the entire post-stroke training period until sacrifice. Recovery was independent of weight loss. Stroke volumes were similar across groups.

CONCLUSIONS

Post-stroke caloric restriction led to recovery of motor function independent of a protective effect on stroke volume. Prehension recovery improved even after ad libitum feeding was reinstituted suggesting that the observed motor recovery was not merely a motivational response. These data add to the growing evidence that post-stroke caloric restriction can enhance recovery.

Targeting sleep and the circadian system as a novel treatment strategy for Parkinson's disease

There is a growing appreciation of the wide range of sleep-wake disturbances that occur frequently in Parkinson's disease. These are known to be associated with a range of motor and non-motor symptoms and significantly impact not only on the quality of life of the patient, but also on their bed partner. The underlying causes for fragmented sleep and daytime somnolence are no doubt multifactorial but there is clear evidence for circadian disruption in Parkinson's disease. This appears to be occurring not only as a result of the neuropathological changes that occur across a distributed neural network, but even down to the cellular level. Such observations indicate that circadian changes may in fact be a driver of neurodegeneration, as well as a cause for some of the sleep-wake symptoms observed in Parkinson's disease. Thus, efforts are now required to evaluate approaches including the prescription of precision medicine to modulate photoreceptor activation ratios that reflect daylight inputs to the circadian pacemaker, the use of small molecules to target clock genes, the manipulation of orexin pathways that could help restore the circadian system, to offer novel symptomatic and novel disease modifying strategies.

Comparison of three methods of intermittent fasting in high-fat-diet-induced obese mice

Purpose

Intermittent fasting (IF), describes a variety of diets that the individual is exposed to intermittent periods of fasting and refeeding. The present study was designed to compare the three most popular intermittent fasting methods in high-fat-diet-induced obese mice.

Methods

50 male C57BL/6 mice were divided into Normal Control (CN), High-Fat Control (CH), IF1 (Alternate Day Fasting), IF2 (Time-Restricted Feeding), IF3 (5:2 Diet) diets. In the first phase of the study, the mice were fed ad libitum either with a 54% Calorie high-fat (CH, IF1, IF2, IF3) or standard CHOW (CN) for 8 weeks. Then, in the intervention phase, the IF groups were fasted for four weeks based on their fasting protocol. At the end of the study, the mice fasting blood, liver and fat tissue samples were biochemically and pathologically assessed.

Results

The weight loss during the fasting period in IF1 and IF2 groups was significantly greater than CH. The epididymal fat pad weight was significantly lower in IF2 and IF3 compared to CH. The serum Triglyceride was significantly greater in CH than in the CN group. The tissue injury scores of the high-fat-diet groups were significantly greater than CN. Also, the tissue injury score was greater in IF1 group compared to the high-fat control group.

Conclusion

All of the fasting protocols can prompt acceptable energy restriction and the ADF and TRF protocols can significantly cause weight loss. Also, the TRF and 5:2 Diets can lower the visceral adiposity. However further human studies focusing on dietary adherence seem necessary.

Caloric restriction for the immunometabolic control of human health

Nutrition affects all physiological processes occurring in our body, including those related to the function of the immune system; indeed, metabolism has been closely associated with the differentiation and activity of both innate and adaptive immune cells. While excessive energy intake and adiposity have been demonstrated to cause systemic inflammation, several clinical and experimental evidence show that calorie restriction (CR), not leading to malnutrition, is able to delay aging and exert potent anti-inflammatory effects in different pathological conditions. This review provides an overview of the ability of different CR-related nutritional strategies to control autoimmune, cardiovascular, and infectious diseases, as tested by preclinical studies and human clinical trials, with a specific focus on the immunological aspects of these interventions. In particular, we recapitulate the state of the art on the cellular and molecular mechanisms pertaining to immune cell metabolic rewiring, regulatory T cell expansion, and gut microbiota composition, which possibly underline the beneficial effects of CR. Although studies are still needed to fully evaluate the feasibility and efficacy of the nutritional intervention in clinical practice, the experimental observations discussed here suggest a relevant role of CR in lowering the inflammatory state in a plethora of different pathologies, thus representing a promising therapeutic strategy for the control of human health.

Ketone flux through BDH1 supports metabolic remodeling of skeletal and cardiac muscles in response to intermittent time-restricted feeding

Time-restricted feeding (TRF) has gained attention as a dietary regimen that promotes metabolic health. This study questioned if the health benefits of an intermittent TRF (iTRF) schedule require ketone flux specifically in skeletal and cardiac muscles. Notably, we found that the ketolytic enzyme beta-hydroxybutyrate dehydrogenase 1 (BDH1) is uniquely enriched in isolated mitochondria derived from heart and red/oxidative skeletal muscles, which also have high capacity for fatty acid oxidation (FAO). Using mice with BDH1 deficiency in striated muscles, we discover that this enzyme optimizes FAO efficiency and exercise tolerance during acute fasting. Additionally, iTRF leads to robust molecular remodeling of muscle tissues, and muscle BDH1 flux does indeed play an essential role in conferring the full adaptive benefits of this regimen, including increased lean mass, mitochondrial hormesis, and metabolic rerouting of pyruvate. In sum, ketone flux enhances mitochondrial bioenergetics and supports iTRF-induced remodeling of skeletal muscle and heart.

Common and divergent molecular mechanisms of fasting and ketogenic diets

Intermittent short-term fasting (ISTF) and ketogenic diets (KDs) exert overlapping but not identical effects on cell metabolism, function, and resilience. Whereas health benefits of KD are largely mediated by the ketone bodies (KBs), ISTF engages additional adaptive physiological responses. KDs act mainly through inhibition of histone deacetylases (HDACs), reduction of oxidative stress, improvement of mitochondria efficiency, and control of inflammation. Mechanisms of action of ISTF include stimulation of autophagy, increased insulin and leptin sensitivity, activation of AMP-activated protein kinase (AMPK), inhibition of the mechanistic target of rapamycin (mTOR) pathway, bolstering mitochondrial resilience, and suppression of oxidative stress and inflammation. Frequent switching between ketogenic and nonketogenic states may optimize health by increasing stress resistance, while also enhancing cell plasticity and functionality.

Transient anticonvulsant effects of time-restricted feeding in the 6-Hz mouse model

INTRODUCTION

Intermittent fasting enhances neural bioenergetics, is neuroprotective, and elicits antioxidant effects in various animal models. There are conflicting findings on seizure protection, where intermittent fasting regimens often cause severe weight loss resembling starvation which is unsustainable long-term. Therefore, we tested whether a less intensive intermittent fasting regimen such as time-restricted feeding (TRF) may confer seizure protection.

METHODS

Male CD1 mice were assigned to either ad libitum-fed control, continuous 8 h TRF, or 8 h TRF with weekend ad libitum food access (2:5 TRF) for one month. Body weight, food intake, and blood glucose levels were measured. Seizure thresholds were determined at various time points using 6-Hz and maximal electroshock seizure threshold (MEST) tests. Protein levels and mRNA expression of genes, enzyme activity related to glucose metabolism, as well as mitochondrial dynamics were assessed in the cortex and hippocampus. Markers of antioxidant defence were evaluated in the plasma, cortex, and liver.

RESULTS

Body weight gain was similar in the ad libitum-fed and TRF mouse groups. In both TRF regimens, blood glucose levels did not change between the fed and fasted state and were higher during fasting than in the ad libitum-fed groups. Mice in the TRF group had increased seizure thresholds in the 6-Hz test on day 15 and on day 19 in a second cohort of 2:5 TRF mice, but similar seizure thresholds at other time points compared to ad libitum-fed mice. Continuous TRF did not alter MEST seizure thresholds on day 28. Mice in the TRF group showed increased maximal activity of pyruvate dehydrogenase in the cortex, which was accompanied by increased protein levels of mitochondrial pyruvate carrier 1 in the cortex and hippocampus. There were no other major changes in protein or mRNA levels associated with energy metabolism and mitochondrial dynamics in the brain, nor markers of antioxidant defence in the brain, liver, or plasma.

CONCLUSIONS

Both continuous and 2:5 TRF regimens transiently increased seizure thresholds in the 6-Hz model at around 2 weeks, which coincided with stability of blood glucose levels during the fed and fasted periods. Our findings suggest that the lack of prolonged anticonvulsant effects in the acute electrical seizure models employed may be attributed to only modest metabolic and antioxidant adaptations found in the brain and liver. Our findings underscore the potential therapeutic value of TRF in managing seizure-related conditions.

Intermittent Fasting Reduces Neuroinflammation and Cognitive Impairment in High-Fat Diet-Fed Mice by Downregulating Lipocalin-2 and Galectin-3

Intermittent fasting (IF), an alternating pattern of dietary restriction, reduces obesity-induced insulin resistance and inflammation. However, the crosstalk between adipose tissue and the hippocampus in diabetic encephalopathy is not fully understood. Here, we investigated the protective effects of IF against neuroinflammation and cognitive impairment in high-fat diet(HFD)-fed mice. Histological analysis revealed that IF reduced crown-like structures and adipocyte apoptosis in the adipose tissue of HFD mice. In addition to circulating lipocalin-2 (LCN2) and galectin-3 (GAL3) levels, IF reduced HFD-induced increases in LCN2- and GAL3-positive macrophages in adipose tissue. IF also improved HFD-induced memory deficits by inhibiting blood-brain barrier breakdown and neuroinflammation. Furthermore, immunofluorescence showed that IF reduced HFD-induced astrocytic LCN2 and microglial GAL3 protein expression in the hippocampus of HFD mice. These findings indicate that HFD-induced adipocyte apoptosis and macrophage infiltration may play a critical role in glial activation and that IF reduces neuroinflammation and cognitive impairment by protecting against blood-brain barrier leakage.

Nutrition and dietary restrictions in cancer prevention

The composition and pattern of dietary intake have emerged as key factors influencing aging, regeneration, and consequently, healthspan and lifespan. Cancer is one of the major diseases more tightly linked with aging, and age-related mortality. Although the role of nutrition in cancer incidence is generally well established, we are far from a consensus on how diet influences tumour development in different tissues. In this review, we will discuss how diet and dietary restrictions affect cancer risk and the molecular mechanisms potentially responsible for their effects. We will cover calorie restriction, intermittent fasting, prolonged fasting, fasting-mimicking diet, time-restricted eating, ketogenic diet, high protein diet, Mediterranean diet, and the vegan and vegetarian diets.

The Investigation of Bone-Implant Connection and New Bone Formation in Fasting and High-Fatty Diet Rats

BACKGROUND

Hyperlipidemia caused by a high-fat diet (HFD) has many adverse effects on the cardiovascular system, including vascular problems. In addition, a HFD also has significant adverse effects on bone health.

AIM

The aim of this study is to examine bone-implant osteointegration and new bone formation in peri-implant defects in fasting and high-fatty diet applied rats.

MATERIALS AND METHODS

In this study, 28 female Sprague Dawley rats were used. The rats were divided into four groups, with seven rats in each group: the control group on a normal diet (Group 1) (n = 7), the fasted group (Group 2) (n = 7), the high-fatty diet (HFD) group (Group 3) (n = 7), and the fasted and HFD group (Group 4) (n = 7). Titanium implants with a diameter of 2.5 mm and a length of 4 mm were placed in the right tibia bones of the subjects, and a bone graft corresponding to 2 mm of the implant length was placed in the bone defect applied to the neck region. All rats that continued the administered diet for 12 weeks were sacrificed at the end of the experiment period. The implants and surrounding bone tissue were surgically removed and subjected to biomechanical analysis to assess bone-implant osteointegration and peri-implant new bone formation.

RESULTS

It was determined that there was no statistically significant difference between the rats in the control group and the other three groups in terms of bone-implant osteointegration and peri-implant new bone formation (P > 0.05).

CONCLUSION

As a result of this study, it was determined that fasting or maintaining a HFD does not adversely affect bone-implant osteointegration or peri-implant new bone formation in the tibias of rats.

Diet-Modifiable Redox Alterations in Ageing and Cancer

With ageing comes some of life's best and worst moments. Those lucky enough to live out into the seventh, eighth, and nineth decades and perhaps beyond have more opportunities to experience the wonders and joys of the world. As the world's population shifts towards more and more of these individuals, this is something to be celebrated. However, it is not without negative consequences. Advanced age also ushers in health decline and the burden of non-communicable diseases such as cancer, heart disease, stroke, and organ function decay. Thus, alleviating or at least dampening the severity of ageing as a whole, as well as these individual age-related disorders will enable the improvement in lifespan and healthspan. In the following chapter, we delve into hypothesised causes of ageing and experimental interventions that can be taken to slow their progression. We also highlight cellular and subcellular mechanisms of ageing with a focus on protein thiol oxidation and posttranslational modifications that impact cellular homeostasis and the advent and progression of ageing-related cancers. By having a better understanding of the mechanisms of ageing, we can hopefully develop effective, safe, and efficient therapeutic modalities that can be used prophylactically and/or concurrent to the onset of ageing.

Ramadan fasting model exerts hepatoprotective, anti-obesity, and anti-hyperlipidemic effects in an experimentally-induced nonalcoholic fatty liver in rats

BACKGROUND

The epidemic of nonalcoholic fatty liver disease (NAFLD) and its metabolic effects present a serious public health concern. We hypothesized that the Ramadan fasting model (RFM), which involves fasting from dawn to dusk for a month, could provide potential therapeutic benefits and mitigate NAFLD. Accordingly, we aimed to validate this hypothesis using obese male rats.

METHODS

Rats were split into two groups (n = 24 per group), and they were given either a standard (S) or high-fat diet (HFD) for 12 weeks. During the last four weeks of the study period, both S- and HFD-fed rats were subdivided into eight groups to assess the effect of RFM with/without training (T) or glucose administration (G) on the lipid profile, liver enzymes, and liver structure (n = 6/group).

RESULTS

The HFD+RFM group exhibited a significantly lower final body weight than that in the HFDC group. Serum cholesterol, low-density lipoprotein, and triglyceride levels were significantly lower in the HFD+RFM, HFD+RFM+T, and HFD+RFM+G groups than those in the HFDC group. Compared with the HFDC group, all groups had improved serum high-density lipoprotein levels. Furthermore, HFD groups subjected to RFM had reduced serum levels of aspartate transaminase and alanine transaminase compared with those of the HFD-fed group. Moreover, the liver histology improved in rats subjected to RFM compared with that of HFD-fed rats, which exhibited macro- and micro-fat droplet accumulation.

CONCLUSION

RFM can induce positive metabolic changes and improve alterations associated with NAFLD, including weight gain, lipid profile, liver enzymes, and hepatic steatosis.

Ubiquitination in the T Cell Metabolism-Based Immunotherapy in Diseases

Metabolism refers to the exchange of matter and energy between the organism and the environment and the self-renewal process of matter and energy in the organism. Metabolic activities in cells provide them with energy and various substrates required for development. Naive T cells differentiate into effector T cells and memory T cells after activation, and this process is accompanied by reprogramming of metabolism-related gene expression. These metabolic changes reflect physiological changes in different stages of T cell activation and differentiation. An increasing number of studies have shown that many autoimmune diseases and organ transplantation are accompanied by disorders and imbalances in T cell metabolism. To treat these diseases, related drugs can be used to regulate T cell activation, differentiation, and function. Therefore, T cell metabolism can serve as a new potential target for regulating immune responses.

Investigating molecular interactions between human transferrin and resveratrol through a unified experimental and computational approach: Role of natural compounds in Alzheimer's disease therapeutics

Disruptions to iron metabolism and iron homeostasis have emerged as significant contributors to the development and progression of Alzheimer's disease (AD). Human transferrin plays a key part in maintaining iron equilibrium throughout the body, highlighting its importance in AD. Many plant-derived compounds and dietary constituents show promise for preventing AD. Polyphenols that are abundant in fruits, vegetables, teas, coffee, and herbs possess neuroprotective attributes. Resveratrol is a natural polyphenol present in various plant sources like grapes, berries, peanuts, and red wine that has garnered research interest due to its wide range of biological activities. Notably, resveratrol exhibits neuroprotective effects that may help prevent or treat AD through multiple mechanisms. In the present study, we employed a combination of molecular docking and all-atom molecular dynamic simulations (MD) along with experimental approaches to unravel the intricate interactions between transferrin and resveratrol deciphering the binding mechanism. Through molecular docking analysis, it was determined that resveratrol occupies the iron binding pocket of transferrin. Furthermore, MD simulations provided a more profound insight into the stability and conformational dynamics of the complex suggesting that the binding of resveratrol introduced localized flexibility, while maintaining overall stability. The spectroscopic observations yielded clear evidence of substantial binding between resveratrol and transferrin, confirming the computational findings. The identified binding mechanism and conformational stability hold potential for advancing the development of innovative therapeutic approaches targeting AD through resveratrol, particularly concerning iron homeostasis. These insights serve as a platform for considering the natural compounds in the realm of AD therapeutics.

Functioning and mechanisms of PTMs in renal diseases

Post-translational modifications (PTMs) are crucial epigenetic mechanisms that regulate various cellular biological processes. The use of mass spectrometry (MS)-proteomics has led to the discovery of numerous novel types of protein PTMs, such as acetylation, crotonylation, 2-hydroxyisobutyrylation, β-hydroxybutyrylation, protein propionylation and butyrylation, succinylation, malonylation, lactylation, and histone methylation. In this review, we specifically highlight the molecular mechanisms and roles of various histone and some non-histone PTMs in renal diseases, including diabetic kidney disease. PTMs exhibit diverse effects on renal diseases, which can be either protective or detrimental, depending on the specific type of protein PTMs and their respective targets. Different PTMs activate various signaling pathways in diverse renal pathological conditions, which could provide novel insights for studying epigenetic mechanisms and developing potential therapeutic strategies for renal diseases.

Intestinal microbiota: A bridge between intermittent fasting and tumors

Intestinal microbiota and their metabolites are essential for maintaining intestinal health, regulating inflammatory responses, and enhancing the body's immune function. An increasing number of studies have shown that the intestinal microbiota is tightly tied to tumorigenesis and intervention effects. Intermittent fasting (IF) is a method of cyclic dietary restriction that can improve energy metabolism, prolong lifespan, and reduce the progression of various diseases, including tumors. IF can affect the energy metabolism of tumor cells, inhibit tumor cell growth, improve the function of immune cells, and promote an anti-tumor immune response. Interestingly, recent research has further revealed that the intestinal microbiota can be impacted by IF, in particular by changes in microbial composition and metabolism. These findings suggest the complexity of the IF as a promising tumor intervention strategy, which merits further study to better understand and encourage the development of clinical tumor intervention strategies. In this review, we aimed to outline the characteristics of the intestinal microbiota and its mechanisms in different tumors. Of note, we summarized the impact of IF on intestinal microbiota and discussed its potential association with tumor suppressive effects. Finally, we proposed some key scientific issues that need to be addressed and envision relevant research prospects, which might provide a theoretical basis and be helpful for the application of IF and intestinal microbiota as new strategies for clinical interventions in the future.

Intermittent Fasting Attenuates Metabolic-Dysfunction-Associated Steatohepatitis by Enhancing the Hepatic Autophagy-Lysosome Pathway

An intermittent fasting (IF) regimen has been shown to protect against metabolic dysfunction-associated steatohepatitis (MASH). However, the precise mechanism remains unclear. Here, we explored how IF reduced hepatic lipid accumulation, inflammation, and fibrosis in mice with MASH. The mice were fed a high-fat diet (HFD) for 30 weeks and either continued on the HFD or were subjected to IF for the final 22 weeks. IF reduced body weight, insulin resistance, and hepatic lipid accumulation in HFD-fed mice. Lipidome analysis revealed that IF modified HFD-induced hepatic lipid composition. In particular, HFD-induced impaired autophagic flux was reversed by IF. The decreased hepatic lysosome-associated membrane protein 1 level in HFD-fed mice was upregulated in HFD+IF-fed mice. However, increased hepatic lysosomal acid lipase protein levels in HFD-fed mice were reduced by IF. IF attenuated HFD-induced hepatic inflammation and galectin-3-positive Kupffer cells. In addition to the increases in hepatic hydroxyproline and lumican levels, lipocalin-2-mediated signaling was reversed in HFD-fed mice by IF. Taken together, our findings indicate that the enhancement of the autophagy-lysosomal pathway may be a critical mechanism of MASH reduction by IF.

Resource allocation strategies for survival and reproduction by an invasive pest in response to intermittent fasting

Intermittent fasting (IF) is a type of dietary restriction that involves fasting periods in intervals, which has been used as a strategy to improve health and extend longevity. Regular fasting is common during the process of biological invasions in nature. Yet, it is not clear how invasive animals adjust their resource allocations to survival and reproduction when periodical starvation occurs. Here, we used Tetranychus ludeni, a haplodiploid spider mite and an important invasive pest of horticultural crops around the world, to investigate the effects of IF on its life history strategies. We show that IF increased the longevity in females but not in males probably because of differences in resource storage, metabolic rate, and mating cost between sexes. In response to IF, females traded off fecundity and egg size but not the number of daughters for longevity gain, suggesting that T. ludeni females can adjust their life history strategies for population survival and growth during invasion process. Eggs produced by fasted females realized the same hatch rate and resultant young had the same survival rate as those by unfasted ones. In addition, IF had transgenerational maternal effects which prolonged offspring development period. We suggest that the longer immature developmental period can increase the body size of resulting adults, compensating egg size loss for offspring fitness. Our findings provide insight into resource allocations as responses to fasting, knowledge of which can be used for evaluation of pest invasions and for management of animal survival and reproduction by dietary regulations.