The Potential of Mitochondrial Therapeutics in the Treatment of Oxidative Stress and Inflammation in Aging.

Mitochondria are central to cellular energy production, and their dysfunction is a major contributor to oxidative stress and chronic inflammation, pivotal factors in aging, and related diseases. With aging, mitochondrial efficiency declines, leading to an increase in ROS and persistent inflammatory responses. Therapeutic interventions targeting mitochondrial health show promise in mitigating these detrimental effects. Antioxidants such as MitoQ and MitoVitE, and supplements like coenzyme Q10 and NAD + precursors, have demonstrated potential in reducing oxidative stress. Additionally, gene therapy aimed at enhancing mitochondrial function, alongside lifestyle modifications such as regular exercise and caloric restriction can ameliorate age-related mitochondrial decline. Exercise not only boosts mitochondrial biogenesis but also improves mitophagy. Enhancing mitophagy is a key strategy to prevent the accumulation of dysfunctional mitochondria, which is crucial for cellular homeostasis and longevity. Pharmacological agents like sulforaphane, SS-31, and resveratrol indirectly promote mitochondrial biogenesis and improve cellular resistance to oxidative damage. The exploration of mitochondrial therapeutics, including emerging techniques like mitochondrial transplantation, offers significant avenues for extending health span and combating age-related diseases. However, translating these findings into clinical practice requires overcoming challenges in precisely targeting dysfunctional mitochondria and optimizing delivery mechanisms for therapeutic agents. Continued research is essential to refine these approaches and fully understand the interplay between mitochondrial dynamics and aging.

Fasting and calorie restriction modulate age-associated immunosenescence and inflammaging.

Aging is a multifaceted process impacting cells, tissues, organs, and organ systems of the body. Like other systems, aging affects both the adaptive and the innate components of the immune system, a phenomenon known as immunosenescence. The deregulation of the immune system puts elderly individuals at higher risk of infection, lower response to vaccines, and increased incidence of cancer. In the Western world, overnutrition has increased the incidence of obesity (linked with chronic inflammation) which increases the risk of metabolic syndrome, cardiovascular disease, and cancer. Aging is also associated with inflammaging a sterile chronic inflammation that predisposes individuals to age-associated disease. Genetic manipulation of the nutrient-sensing pathway, fasting, and calorie restriction (CR) has been shown to increase the lifespan of model organisms. As well in humans, fasting and CR have also been shown to improve different health parameters. Yet the direct effect of fasting and CR on the aging immune system needs to be further explored. Identifying the effect of fasting and CR on the immune system and how it modulates different parameters of immunosenescence could be important in designing pharmacological or nutritional interventions that slow or revert immunosenescence and strengthen the immune system of elderly individuals. Furthermore, clinical intervention can also be planned, by incorporating fasting or CR with medication, chemotherapy, and vaccination regimes. This review discusses age-associated changes in the immune system and how these changes are modified by fasting and CR which add information on interventions that promote healthy aging and longevity in the growing aging population.

Effect of 5:2 intermittent fasting diet versus daily calorie restriction eating on metabolic-associated fatty liver disease-a randomized controlled trial.

Objective: Both 5:2 IF diet (intermittent fasting) and daily caloric restriction eating had been suggested for management of MAFLD (Metabolic-Associated Fatty Liver Disease), this study aimed to evaluate the effects of 5:2 IF diet on body weight and metabolic parameters in adults with MAFLD, in comparison to daily caloric restriction eating. Methods: This single-center, double-blind, prospective, randomized controlled trial included 60 patients with MAFLD, who were administered either a 5:2 IF diet limited calories consumed for 2 days each week with no restrictions on the remaining 5 (Group 5:2 IF diet) or a daily calorie restriction eating (Group daily calorie restriction). Fibrotouch-B instrument assessment, ultrasound assessment of hepatic steatosis, anthropometric indices and body composition analysis, blood sample measurements were conducted during two distinct visits: initially on the day of study commencement (T1), and subsequently at the conclusion of the 12-week intervention period (T2). Results: In comparison to daily calorie restriction eating, the 5:2 IF diet significantly decreased the proportion of hepatic steatosis ≥moderate (29.6% vs. 59.3%, p = 0.028) and the degree of hepatic fibrosis F ≥ 2 (3.7% vs. 25.9%, p = 0.05), and fewer percentage of patients were diagnosed with fatty liver via upper abdominal ultrasound in the 5:2 intermittent fasting diet group (33.3% vs. 63.0%, p = 0.029). Additionally, the CAP (controlled attenuation parameter) and LSM (liver stiffness measurements) value were significantly lower in the 5:2 IF diet group (p < 0.05). No statistically significant differences were observed between the two groups in terms of weight, BMI (body mass index), WC (waist circumference), HC (hip circumference), and WHR (waist to hip ratio). Similarly, there were no significant differences in lipid profile, glycemic indices and adverse events (p > 0.05). Conclusion: In summary, although both 5:2 IF diet and daily caloric restriction eating achieved similar effect on body weight, liver enzymes, lipid profile and glycemic indices after 12 weeks treatment, 5:2 IF diet demonstrates better improvement in fibrosis and steatosis scores independently from weight regulation. Consequently, it is anticipated to emerge as a viable dietary modality for lifestyle intervention among patients diagnosed with MAFLD. Clinical trial registration: https://www.crd.york.ac.uk/PROSPERO, identifier ChiCTR2400080292.

Non-canonical metabolic and molecular effects of calorie restriction are revealed by varying temporal conditions.

Calorie restriction (CR) extends lifespan and healthspan in diverse species. Comparing ad libitum- and CR-fed mice is challenging due to their significantly different feeding patterns, with CR-fed mice consuming their daily meal in 2 h and then subjecting themselves to a prolonged daily fast. Here, we examine how ad libitum- and CR-fed mice respond to tests performed at various times and fasting durations and find that the effects of CR-insulin sensitivity, circulating metabolite levels, and mechanistic target of rapamycin 1 (mTORC1) activity-result from the specific temporal conditions chosen, with CR-induced improvements in insulin sensitivity observed only after a prolonged fast, and the observed differences in mTORC1 activity between ad libitum- and CR-fed mice dependent upon both fasting duration and the specific tissue examined. Our results demonstrate that much of our understanding of the effects of CR are related to when, relative to feeding, we choose to examine the mice.

Caloric and time restriction diets improve acute kidney injury in experimental menopausal rats: role of silent information regulator 2 homolog 1 and transforming growth factor beta 1.

BACKGROUND: Estrogen has a protective impact on acute kidney injury (AKI); moreover, reducing the daily intake of calories impedes developing diseases. The present study aimed to determine the effects of calorie restriction (CR) and time restriction (TR) diets on the expression of silent information regulator 2 homolog 1 (SIRT1), transforming growth factor beta 1 (TGF-ß1), and other indicators in the presence and absence of ovaries in AKI female rats. METHODS: The female rats were divided into two groups, ovariectomized (OVX) and sham, and were placed on CR and TR diets for eight weeks; afterward, AKI was induced by injecting glycerol, and kidney injury indicators and biochemical parameters were measured before and after AKI. RESULTS: After AKI, the levels of urine albumin excretion rate, urea, and creatinine in serum, and TGF-ß1 increased, while creatinine clearance and SIRT1 decreased in kidney tissue. CR improved kidney indicators and caused a reduction in TGF-ß1 and an increase in SIRT1 in ovary-intact rats. Moreover, CR prevented total antioxidant capacity (TAC) decrease and malondialdehyde (MDA) increase resulting from AKI. Before AKI, an increase in body weight, fasting blood sugar (FBS), low-density lipoprotein (LDL), triglyceride (TG), and total cholesterol (TC), and a decrease in high-density lipoprotein (HDL) were observed in OVX rats compared to sham rats, but CR prevented these changes. The effects of TR were similar to those of CR in all indicators except for TGF-ß1, SIRT1, urea, creatinine, and albumin. CONCLUSION: The present study indicated that CR is more effective than TR in preventing AKI, probably by increasing SIRT1 and decreasing TGF-ß1 in ovary-intact animals.

Comparative effects of 8-week combined resistance exercise training and alternate-day calorie restriction on soluble epidermal growth factor receptor (sEGFR) and adipsin in obese men.

This study investigated the combined effects of resistance exercise training (RET) and alternate-day calorie restriction (ADCR) on body composition, insulin resistance (IR), insulin resistance-related biomarkers (adipokine adipsin and hepatokine soluble EFGR), and weight loss in obese men. The findings revealed that RET + ADCR induced the greatest reductions in body weight, body fat percentage, and waist-to-hip ratio (WHR) compared to RET and ADCR alone (p < 0.05). Additionally, RET + ADCR resulted in the most significant improvements in IR, as measured by HOMA-IR, and in circulating levels of adipsin and soluble EFGR (p < 0.05). These findings suggest that combining RET and ADCR may be a more effective strategy for improving metabolic health, including body composition, IR, and metabolic tissues' functions, in obese men than either intervention alone.

Advances in Diet and Physical Activity in Breast Cancer Prevention and Treatment.

There is currently a growing interest in diets and physical activity patterns that may be beneficial in preventing and treating breast cancer (BC). Mounting evidence indicates that indeed, the so-called Mediterranean diet (MedDiet) and regular physical activity likely both help reduce the risk of developing BC. For those who have already received a BC diagnosis, these interventions may decrease the risk of tumor recurrence after treatment and improve quality of life. Studies also show the potential of other dietary interventions, including fasting or modified fasting, calorie restriction, ketogenic diets, and vegan or plant-based diets, to enhance the efficacy of BC therapies. In this review article, we discuss the biological rationale for utilizing these dietary interventions and physical activity in BC prevention and treatment. We highlight published and ongoing clinical studies that have applied these lifestyle interventions to BC patients. This review offers valuable insights into the potential application of these dietary interventions and physical activity as complimentary therapies in BC management.

Long-term Changes in Body Composition and Exercise Capacity Following Calorie Restriction and Exercise Training in Older Patients with Obesity and Heart Failure With Preserved Ejection Fraction.

BACKGROUND: Obesity combined with heart failure with preserved ejection fraction (HFpEF) is the dominant form of HF among older persons. In a randomized trial, we previously showed that a 5-month calorie restriction (CR) program, with or without aerobic exercise training (AT), resulted in significant weight and fat loss and improved exercise capacity. However, little is known regarding the long-term effects of these outcomes after a short-term (5-month) intervention of CR with or without AT in older patients with obesity and HFpEF. METHODS: Sixteen participants from either the CR or CR+AT who experienced significant weight loss ≥ 2 kg were reexamined after a long-term follow-up endpoint (28.0 ± 10.8 months) without intervention. The follow-up assessment included body weight and composition via dual-energy X-ray absorptiometry and exhaustive cardiopulmonary treadmill exercise testing. RESULTS: Compared to the 5-month time-point intervention endpoint, at the long-term follow-up endpoint, mean body weight increased +5.2 ± 4.0 kg (90.7 ± 11.2 kg vs 95.9 ± 11.9; P < 0.001) due to increased fat mass (38.9 ± 9.3 vs 43.8 ± 9.8; P < 0.001) with no change in lean mass (49.6 ± 7.1 vs 49.9±7.6; P = 0.67), resulting in worse body composition (decreased lean-to-fat mass). Change in total mass was strongly and significantly correlated with change in fat mass (r = 0.75; P < 0.001), whereas there appeared to be a weaker correlation with change in lean mass (r = 0.50; P = 0.051). Additionally, from the end of the 5-month time-point intervention endpoint to the long-term follow-up endpoint, there were large, significant decreases in VO2peak (-2.2 ± 2.1 mL/kg/min; P = 0.003) and exercise time (-2.4 ± 2.6 min; P = 0.006). There appeared to be an inverse correlation between the change in VO2peak and the change in fat mass (r = -0.52; P = 0.062). CONCLUSION: Although CR and CR+AT in older patients with obesity and HFpEF can improve body composition and exercise capacity significantly, these positive changes diminish considerably during long-term follow-up endpoints, and regained weight is predominantly adipose, resulting in worsened overall body composition compared to baseline. This suggests a need for long-term adherence strategies to prevent weight regain and maintain improvements in body composition and exercise capacity following CR in older patients with obesity and HFpEF.

Dietary methionine functions in proliferative zone maintenance and production of eggs via sams-1 in Caenorhabditis elegans.

The maintenance of germ cells is critical for the prosperity of offspring. The amount of food consumption is known to be closely related to reproduction, i.e., the number of eggs decreases under calorie-restricted conditions in various organisms. Previous studies in Caenorhabditis elegans have reported that calorie restriction reduces the number of eggs and the reduction can be rescued by methionine. However, the effect of methionine on the reproductive process has not been fully understood. In this study, to assess the gonadal function of methionine metabolism, we firstly demonstrated that a depletion in dietary methionine resulted in reduced levels of S-adenosyl-l-methionine (SAM) and S-adenosyl homocysteine (SAH) in wild-type N2, but not in glp-1 mutants, which possess only a few germ cells. Second, we found no recovery in egg numbers upon methionine administration in SAM synthase (sams)-1 mutants. Furthermore, a reduced number of proliferative zone nuclei exhibited in the sams-1 mutants was not rescued via methionine. Thus, our results have shown that dietary methionine is required for the normal establishment of both the germline progenitor pool and fecundity, mediated by sams-1.

CYB5R3 overexpression exhibits sexual dimorphism: Mitochondrial and metabolic adaptations in transgenic female mice during calorie restriction.

There is a pressing need to develop new strategies for enhancing health in the elderly and preventing the rise in age-related diseases. Calorie restriction without malnutrition (CR) stands among the different antiaging interventions. Lifelong CR leads to increased expression and activity of plasma membrane CYB5R3, and male mice overexpressing CYB5R3 exhibit some beneficial adaptations that are also seen with CR. However, the mechanisms involved in both interventions could be independent since key aspects of energy metabolism and tissue lipid profile do not coincide, and many of the changes induced by CR in mitochondrial abundance and dynamics in the liver and skeletal muscle could be counteracted by CYB5R3 overexpression. In this study, we sought to elucidate the impact of CR on key markers of metabolic status, mitochondrial function, and pro-oxidant/antioxidant balance in transgenic (TG) female mice overexpressing CYB5R3 compared to their WT littermates. In females fed ad libitum, CYB5R3 overexpression decreased fat mass, led to a preferred utilization of fatty acids as an energy source, upregulated key antioxidant enzymes, and boosted respiration both in skeletal muscle and liver mitochondria, supporting that CYB5R3 overexpression is phenotypic closer to CR in females than in males. Whereas some markers of mitochondrial biogenesis and dynamics were found decreased in TG females on CR, as also found for the levels of Estrogen Receptor α, mitochondrial abundance and activity were maintained both in skeletal muscle and in liver. Our results reveal overlapping metabolic adaptations resulting from the overexpression of CYB5R3 and CR in females, but a specific crosstalk occurs when both interventions are combined, differing from the adaptations observed in TG males.

Effects of calorie-restricted diet on health state and intestinal flora in Hashimoto's thyroiditis patients: Study protocol for a randomized controlled trial.

BACKGROUND AND OBJECTIVES: Hashimoto's thyroiditis (HT) is an autoimmune disease, characterized by abnormal elevation in thyroid peroxidase antibody and/or thyroglobulin antibody. In recent decades, HT disease has become more and more widespread. Patients always report multiple symptoms, even though their thyroid hormone levels are kept in normal ranges. However, no treatment exists to effectively reduce the levels of thyroid antibodies. Our study aims to determine whether calorie-restricted diet is helpful in improving health of HT patients. METHODS AND STUDY DESIGN: This is a 3-month randomized controlled trial. HT patients will be randomized into a calorie-restricted (CR) group or a calorie-unrestricted control group. All the participants will be instructed to consume a diet that includes a combination of 45-55% calories from carbohydrates, 20-30% from fats, and 15-25% from proteins, according to current Chinese Dietary Guidelines. Participants in CR group need to limit their calories intake equal to their basal energy expenditure, which means that their daily caloric intake will be limited by about 20-30%. RESULTS: The study population is planned to be 66 HT patients aged 18 to 65 years. The primary outcome is change of thyroid antibody levels from baseline. Secondary outcomes include the changes of non-hypothyroid symptoms scores, thyroid function indexes, morphology of thyroid, T lymphocyte subpopulations, inflammatory biomarkers and lipids from baseline to 12 weeks. CONCLUSIONS: This trial will have implications for nutrition treatment policy in regard to thyroid antibodies control, immune dysfunction and related non-hypothyroid symptoms improvement among HT patients.

Assessment of EN-RAGE, sRAGE, and its isoforms: cRAGE, esRAGE in obese patients treated by moderate caloric restriction combined with physical activity conducted in hospital condition.

BACKGROUND: AGEs, their receptor (RAGE), and the extracellular newly identified receptor for AGEs product-binding protein (EN-RAGE) are implicated in the pathogenesis of inflammation. AIM: We analyzed serum EN-RAGE, soluble RAGE (sRAGE), and their isoforms: endogenous secretory - esRAGE and cleaved - cRAGE concentrations in lean controls (n = 74) and in patients with obesity (n = 71) treated for three weeks with moderate calorie restriction (CR) combined with physical activity in a hospital condition. METHODS: Using the ELISA method, serum sRAGE, esRAGE, and EN-RAGE were measured before and after CR. RESULTS: The serum level of sRAGE and esRAGE in patients with obesity was lower than that in non-obese individuals, contrary to cRAGE. EN-RAGE concentration was about three times higher in obese patients. Gradually, a rise in BMI resulted in sRAGE, esRAGE reduction, and EN-RAGE increase. The sRAGE concentration was sex-dependent, indicating a higher value in lean men. A moderate negative correlation was observed between BMI and all RAGE isoforms, whereas EN-RAGE displays a positive correlation. CR resulted in an expected decrease in anthropometric, metabolic, and proinflammatory parameters and EN-RAGE, but no RAGE isoforms. The ratio EN-RAGE/sRAGE was higher in obese humans than in control and was not modified by CR. CONCLUSION: Obesity decreases sRAGE and esRAGE and increases EN-RAGE concentration. Moderate CR and physical activity by decreasing inflammation reduces EN-RAGE but is insufficient to increase sRAGE and esRAGE to the extent observed in lean patients. EN-RAGE instead of sRAGE could be helpful to indicate a better outcome of moderate dietary intervention in obese subjects.

Benefits of calorie restriction in mice are mediated via energy imbalance, not absolute energy or protein intake.

Caloric restriction (CR) results in reduced energy and protein intake, raising questions about protein restriction's contribution to CR longevity benefits. We kept ad libitum (AL)-fed male C57BL/6J mice at 27°C (AL27) and pair-fed (PF) mice at 22°C (22(PF27)). The 22(PF27) group was fed to match AL27 while restricted for calories due to cold-induced metabolism. The 22(PF27) mice had significantly lower body weight, lean mass, fat mass, leptin, IGF-1, and TNF-α levels than AL27 mice (p<0.001 for all). Manipulations over ~11 weeks resulted in significant differences in body temperature, physical activity, and expression of key genes linked to hunger in the hypothalamus. Survival was significantly greater in 22(PF27) compared to AL27 overall (p<0.001). CR in the context of equivalent energy and protein intake resulted in hormonal, metabolic, and physiological benefits and extended longevity. Hence, energy imbalance, rather than low energy or protein intake per se, mediates the benefits of CR.

Effects of endurance training under calorie restriction on energy substrate metabolism in mouse skeletal muscle and liver.

We investigated whether calorie restriction (CR) enhances metabolic adaptations to endurance training (ET). Ten-week-old male Institute of Cancer Research (ICR) mice were fed ad libitum or subjected to 30% CR. The mice were subdivided into sedentary and ET groups. The ET group performed treadmill running (20-25 m/min, 30 min, 5 days/week) for 5 weeks. We found that CR decreased glycolytic enzyme activity and monocarboxylate transporter (MCT) 4 protein content, while enhancing glucose transporter 4 protein content in the plantaris and soleus muscles. Although ET and CR individually increased citrate synthase activity in the plantaris muscle, the ET-induced increase in respiratory chain complex I protein content was counteracted by CR. In the soleus muscle, mitochondrial enzyme activity and protein levels were increased by ET, but decreased by CR. It has been suggested that CR partially interferes with skeletal muscle adaptation to ET.

Quality of Life and Its Association With Time in Range Among People With Type 2 Diabetes Mellitus Following Different Dietary Interventions: A Crossover Clinical Trial.

Background Quality of Life (QoL) is an essential consideration in healthcare. Numerous studies have examined QoL in India; however, data on QoL following different dietary interventions are lacking. Similarly, the use of technology such as continuous glucose monitoring (CGM) for diabetes care has independently demonstrated improvements in glycemic control; however, its association with QoL remains limited. Purpose The purpose was to study the role of different dietary interventions on QoL and its association with Time in Range (TIR), Time Above Range (TAR), and Time Below Range (TBR) among the Type 2 Diabetes Mellitus (T2DM) population. Methodology A crossover interventional clinical trial (CTRI/2022/07/044356) was conducted among participants with T2DM of less than 5 years' duration, aged between 25 and 55 years, with an HbA1c level of less than 8%, and who were on Metformin only. Their QoL was assessed after following two diet patterns: the Continuous Calorie Restricted Diet (CCRD) - calorie reduction with small frequent meals, and Time Restricted Intermittent Fasting (TRIF) - calorie reduction with only two meals a day, using the Modified QoL (MDQOL-17) questionnaire. The association between post-dietary interventions QoL and TIR was studied using a 14-day CGM device. Results The overall QoL of 51 participants at the end of the dietary interventions was significantly better compared to their QoL before any dietary intervention (85.6±19.0% and 63.1±13.0%, respectively, p = 0.000). Decreased TIR correlated with increased role limitations due to physical functioning (p = 0.002) and decreased energy levels (p = 0.00). As TBR increased, role limitation due to emotional well-being increased, and energy levels decreased significantly (p = 0.01). As TAR increased, energy levels decreased (p = 0.01). A simple linear regression model was statistically significant for role limitations due to physical functioning (p = 0.003) and energy fatigue (p = 0.000), suggesting that higher TIR is associated with higher scores in these domains. Conclusion Dietary interventions that improve the TIR and reduce the TAR and TBR can enhance the QoL of individuals with T2DM.

Functional outcomes of diets in multiple sclerosis (FOOD for MS): Protocol for a parallel arm randomized feeding trial for low glycemic load and calorie restriction.

BACKGROUND: Pilot trials indicate that both a low glycemic load (GL) diet and calorie restriction (CR) can be implemented successfully in people with multiple sclerosis (pMS) and may improve MS symptoms and physical function, but large randomized clinical trials (RCTs) have not yet been conducted. The purpose of this study is to test these interventions alone and in combination to determine their efficacy for improving clinical and patient reported outcomes (PROs) in pMS. METHODS: This 32-week, two-arm, RCT at two centers will randomly assign 100 adults with relapsing-remitting or secondary progressive MS to a low GL diet (n = 50) or a standard GL diet (n = 50). Both diet groups will complete two study phases: a eucaloric phase (16 weeks) and a CR phase (16 weeks). Groceries for the study meal plans will be delivered to participants' homes weekly. The primary outcome is physical function, measured by timed 25-ft walk test. Secondary outcomes are pain, fatigue, mood, and anxiety. DISCUSSION: This will be the most rigorous intervention trial to date of a low GL diet and CR in adults with MS, and among the first to assess the impact of intentional weight loss on MS symptoms. Results will provide valuable insight for recommending dietary change, weight loss, or both to adults with MS. These non-drug interventions pose few risks and have potential to yield significant improvements in MS symptoms. TRIAL REGISTRATION ID: NCT05327322.

Quantification of healthspan in aging mice: introducing FAMY and GRAIL.

The population around the world is graying, and as many of these individuals will spend years suffering from the burdens of age associated diseases, understanding how to increase healthspan, defined as the period of life free from disease and disability, is an urgent priority of geroscience research. The lack of agreed-upon quantitative metrics for measuring healthspan in aging mice has slowed progress in identifying interventions that do not simply increase lifespan, but also healthspan. Here, we define FAMY (Frailty-Adjusted Mouse Years) and GRAIL (Gauging Robust Aging when Increasing Lifespan) as new summary statistics for quantifying healthspan in mice. FAMY integrates lifespan data with longitudinal measurements of a widely utilized clinical frailty index, while GRAIL incorporates these measures and also adds information from widely utilized healthspan assays and the hallmarks of aging. Both metrics are conceptually similar to quality-adjusted life years (QALY), a widely utilized measure of disease burden in humans, and can be readily calculated from data acquired during longitudinal and cross-sectional studies of mouse aging. We find that interventions generally thought to promote health, including calorie restriction, robustly improve healthspan as measured by FAMY and GRAIL. Finally, we show that the use of GRAIL provides new insights, and identify dietary restriction of protein or isoleucine as interventions that robustly promote healthspan but not longevity in female HET3 mice. We suggest that the routine integration of these measures into studies of aging in mice will allow the identification and development of interventions that promote healthy aging even in the absence of increased lifespan.

The effects of dietary macronutrient composition on resting energy expenditure following active weight loss: A systematic review and meta-analysis.

A systematic review and meta-analysis was conducted to evaluate the relative effectiveness of different dietary macronutrient patterns on changes in resting energy expenditure (REE) in relation to weight loss, categorized as minimal (<5%) and moderate to high (>5%). Changes in REE were assessed using a DerSimonian and Laird random-effects meta-analysis. A diet lower in carbohydrates (CHO) or higher in fat and protein was associated with smaller reductions in REE, with these trends being more pronounced among participants who experienced moderate to high weight loss. Adjusted meta-regression analysis indicated that, within the participants who experienced moderate to high weight loss, each 1% increase in CHO intake was associated with a reduction of 2.30 kcal/day in REE (95% CI: -4.11 to -0.47, p = 0.013). In contrast, a 1% increase in protein and fat intake was correlated with an increase in REE by 3.00 (95% confidence interval [CI] [1.02, 5.07], p = 0.003) and 0.5 (95% CI [-2.43, 3.41], p = 0.740) kcal/day, respectively. No significant associations were found among participants who experienced minimal weight loss. These findings indicate that, under a caloric deficit, the impact of dietary macronutrient composition on REE may vary depending on the degree of weight loss and individual metabolic responses.

Long-term calorie restriction reduces oxidative DNA damage to oligodendroglia and promotes homeostatic microglia in the aging monkey brain.

Calorie restriction (CR) is a robust intervention that can slow biological aging and extend lifespan. In the brain, terminally differentiated neurons and glia accumulate oxidative damage with age, reducing their optimal function. We investigated if CR could reduce oxidative DNA damage to white matter oligodendrocytes and microglia. This study utilized post-mortem brain tissue from rhesus monkeys that died after decades on a 30 % reduced calorie diet. We found that CR subjects had significantly fewer cells with oxidative damage within the corpus callosum and the cingulum bundle. Oligodendrocytes specifically showed the greatest response to CR with a robust reduction in DNA damage. Additionally, we observed alterations in microglia morphology with CR subjects having a higher proportion of ramified, homeostatic microglia and fewer pro-inflammatory, hypertrophic microglia relative to controls. Furthermore, we determined that the observed attenuation in damaged DNA occurs primarily within mitochondria. Overall, these data suggest that long-term CR can reduce oxidative DNA damage and offer a neuroprotective effect in a cell-type-specific manner in the aging monkey brain.

SIRT1, resveratrol and aging.

Aging is linked to a time-associated decline in both cellular function and repair capacity leading to malfunction on an organismal level, increased frailty, higher incidence of diseases, and death. As the population grows older, there is a need to reveal mechanisms associated with aging that could spearhead treatments to postpone the onset of age-associated decline, extend both healthspan and lifespan. One possibility is targeting the sirtuin SIRT1, the founding member of the sirtuin family, a highly conserved family of histone deacetylases that have been linked to metabolism, stress response, protein synthesis, genomic instability, neurodegeneration, DNA damage repair, and inflammation. Importantly, sirtuins have also been implicated to promote health and lifespan extension, while their dysregulation has been linked to cancer, neurological processes, and heart disorders. SIRT1 is one of seven members of sirtuin family; each requiring nicotinamide adenine dinucleotide (NAD+) as co-substrate for their catalytic activity. Overexpression of yeast, worm, fly, and mice SIRT1 homologs extend lifespan in each animal, respectively. Moreover, lifespan extension due to calorie restriction are associated with increased sirtuin activity. These findings led to the search for a calorie restriction mimetic, which revealed the compound resveratrol; (3, 5, 4'-trihydroxy-trans-stilbene) belonging to the stilbenoids group of polyphenols. Following this finding, resveratrol and other sirtuin-activating compounds have been extensively studied for their ability to affect health and lifespan in a variety of species, including humans via clinical studies.