A 2-Year Randomized Controlled Trial of Human Caloric Restriction: Feasibility and Effects on Predictors of Health Span and Longevity

Increasing the health span: unique role for exercise

Health span, that period between birth and onset of major disease(s), when adequate physical and cognitive function permit those daily living activities essential to life quality, is lower in the United States than other developed countries. Physical inactivity and excessive calorie intake occupy dominant roles both in the problem, and by redressing them, in the solution. Consequently, this review focuses on evidence that appropriate exercise engagement and calorie restriction (CR) can improve physical and mental health with a view to extending the health span. Humanity, writ large, has grasped these underlying concepts for Millennia but has been largely intransigent to them. Thus, the final section proposes a novel Monty Python-esque approach that encompasses humanity's inimical sense of humor to increase physical fitness and mental health, restore energy balance, sustain better cognitive function, and extend the health span.

Age-associated changes in the heart: implications for COVID-19 therapies

Cardiac aging involves progressive structural, functional, cellular, and molecular changes that impair heart function. This review explores key mechanisms, including oxidative stress, mitochondrial dysfunction, impaired autophagy, and chronic low-grade inflammation. Excess reactive oxygen species (ROS) damage heart muscle cells, contributing to fibrosis and cellular aging. Mitochondrial dysfunction reduces energy production and increases oxidative stress, accelerating cardiac decline. Impaired autophagy limits the removal of damaged proteins and organelles, while inflammation activates signaling molecules that drive tissue remodeling. Gender differences reveal estrogen's protective role in premenopausal women, with men showing greater susceptibility to heart muscle dysfunction and injury. After menopause, women lose this hormonal protection, increasing their risk of cardiovascular conditions. Ethnic disparities, particularly among underserved minority populations, emphasize how social factors such as access to care, environment, and chronic stress contribute to worsening cardiovascular outcomes. The coronavirus disease pandemic has introduced further challenges by increasing the incidence of heart damage through inflammation, blood clots, and long-term heart failure, especially in older adults with existing metabolic conditions like diabetes and high blood pressure. The virus's interaction with receptors on heart and blood vessel cells, along with a weakened immune response in older adults, intensifies cardiac aging. Emerging therapies include delivery of therapeutic extracellular vesicles, immune cell modulation, and treatments targeting mitochondria. In addition, lifestyle strategies such as regular physical activity, nutritional improvements, and stress reduction remain vital to maintaining cardiac health. Understanding how these biological and social factors intersect is critical to developing targeted strategies that promote healthy aging of the heart.

Healthy ageing in older adults with cardiovascular disease

As life expectancy continues to increase due to advancements in medical technology, public health, nutrition, and socioeconomic progress, the population of older adults in the USA and Europe is rapidly growing. By 2050, individuals aged 65 and older are projected to constitute over 20% of the US population and 29% of the European population, leading to a higher prevalence of chronic diseases, including cardiovascular disease. Cardiovascular disease, the leading cause of death in the USA, poses significant challenges to healthy ageing by contributing to accelerated biological ageing and the development of geriatric syndromes. This state-of-the-art review aims to (i) define healthy ageing for older patients living with cardiovascular disease; (ii) compare chronological vs biological ageing as it pertains to cardiovascular disease; (iii) describe the impact of geriatric syndromes and provide an approach to management and prevention; and (iv) address the gaps in knowledge and future directions for potential interventions that could promote healthy ageing.

Biological Effects of Dietary Restriction on Alzheimer's Disease: Experimental and Clinical Investigations

BACKGROUNDS

Dementia can impose a heavy economic burden on both society and families. Alzheimer's disease (AD), the most prevalent form of dementia, is a complex neurodegenerative disease characterized by the abnormal deposition of extracellular amyloid β-protein (Aβ) and the aggregation of intracellular Tau protein to form neurofibrillary tangles (NFTs). Given the limited efficacy of pharmacological treatment, scientists have already paid more attention to non-pharmacological strategies, including dietary restriction (DR). DR refers to a nutritional paradigm aimed at promoting overall health by modifying the balance between energy consumption and expenditure. Studies have demonstrated that DR effectively extends the healthy lifespan, delays the aging process, and achieves promising results in the prevention and treatment of AD in preclinical studies.

METHODS

In this review we collected related studies and viewpoints by searching on PubMed database using the keywords. Most of the citations were published between 2015 and 2025. A few older literatures were also included due to their relevance and significance in this field.

RESULTS

We first provide a concise overview of the current therapeutic and preventive strategies for AD. Then, we introduce several specific DR protocols and their favorable effects on AD. Furthermore, the potential mechanisms underlying the benefits of DR on AD are discussed. Finally, we briefly highlight the role of DR in maintaining brain health.

CONCLUSION

This review may offer valuable insights into the development of innovative non-pharmacological strategies for AD treatment.

Deciphering the role of cytokines in aging: Biomarker potential and effective targeting

Aging is often characterized by chronic inflammation, immune system dysregulation, and cellular senescence with chronically elevated levels of pro-inflammatory cytokines. These small glycoproteins are mainly secreted by immune cells, mediating intercellular communication and immune system modulation through inflammatory signaling. Their pro- and anti-inflammatory effects make them a noteworthy research topic as well as a promising ally in combating inflammation and the aging process. Cytokines exert a synergistic role in aging and disease and may prove useful biomarkers of tissue-specific dysregulation, disease diagnosis and monitoring, presenting potential therapeutic options as anti-inflammatory and senolytic medications. In this review, we address the cellular and molecular mechanisms implicating cytokines in the aging process and related diseases, highlighting their biomarker potential. We focus on the current therapeutic strategies, including specific pharmaceutical agents, supplements, a balanced diet, and healthy habits such as exercise, stress management, and caloric restriction.

Molecular Targets of 20-Hydroxyecdysone in Mammals, Mechanism of Action: Is It a Calorie Restriction Mimetic and Anti-Aging Compound?

The 20-hydroxyecdysone (20E) has been used in traditional medicine for a long time and acquired attention in the last decade as a food supplement and stimulant in physical activities. This polyhydroxylated cholesterol is found in the highest concentration in plants, and it is one of the secondary plant products that has a real hormonal influence in arthropods. Various beneficial effects have been reported in vivo and in vitro for 20E and its related compounds in mammals. Trials for the safety of clinical application showed a remarkably high tolerance in humans. This review aims to assess the latest development in the involvement of various pathways in tissues and organs and look if it is plausible to find a single primary target of this compound. The similarities with agents mimicking calorie restriction and anti-aging effects are also elucidated and discussed.

Caloric restriction reprograms adipose tissues in rhesus monkeys

Caloric restriction (CR) is a dietary intervention that delays the onset of age-related diseases and enhances survival in diverse organisms, and although changes in adipose tissues have been implicated in the beneficial effects of CR the molecular details are unknown. Here we show shared and depot-specific adaptations to life-long CR in subcutaneous and visceral adipose depots taken from advanced age male rhesus monkeys. Differential gene expression and pathway analysis identified key differences between the depots in metabolic, immune, and inflammatory pathways. In response to CR, RNA processing and proteostasis-related pathways were enriched in both depots but changes in metabolic, growth, and inflammatory pathways were depot-specific. Commonalities and differences that distinguish adipose depots are shared among monkeys and humans and the response to CR is highly conserved. These data reveal depot-specificity in adipose tissue adaptation that likely reflects differences in function and contribution to age-related disease vulnerability.

tRNA-Derived Fragments in Age-Related Diseases: A Systematic Review

Aging is a progressive weakening of numerous functions of organisms resulting in diminished abilities to safeguard against environmental damage and augment physiological harmony. It is not a disease in itself; however, it is a main cause of debilitating and life-threatening chronic aging-related diseases (ARDs). tRNA-derived fragments (tDRs) are stable forms of tRNAs of 14-35 nt in length that function as regulatory small-RNA molecules. Here we aimed to perform a systematic review of original articles on the involvement of tDRs in the etiology of ARDs: their identification and characterization. The systematic review was conducted according to the Cochrane Handbook guidelines and the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. Based on the eligibility criteria defined for the study, 21 original articles were included in this systematic review, covering 11 ARDs. The preferred research method used to study tDRs was high-throughput sequencing combined with RT-qPCR, and as a result, a number of tDRs were implicated in ARDs. Importantly, an in-depth analysis of the articles allowed us to identify several shortcomings: (i) the tDRs nomenclature varies between studies and articles, making it often difficult to precisely identify molecules differentiating in a given disease; (ii) the chosen tDRs have all been studied for a miRNA-like mechanism of action; however, tDRs also function in RNAi-independent ways, which need to be studied as well; (iii) to precisely identify tDRs, the sequencing techniques that overcome the issues of modifications harbored by tRNAs must be used.

Improving weight loss and cardiometabolic risk in black patients with diabetes or pre-diabetes: Rationale and protocol for a digital medicine hybrid type 1 implementation trial

BACKGROUND

The goal of the PROPEL-IT study is to conduct an effectiveness-implementation (hybrid type 1) study to 1) test the effectiveness of a digital technology focused 24-month, patient-centered precision public health approach to weight-loss, facilitated by an electronic medical record (EMR) in Black patients with obesity and type 2 diabetes mellitus or prediabetes, and 2) better understand the external validity and context for implementation.

METHODS

Patients in the Intensive Lifestyle Intervention (ILI) participate in a high-intensity behavioral intervention to facilitate weight loss through reducing dietary intake and increasing physical activity. The ILI is delivered by health coaches in the digital medicine program of a large health care organization facilitated by the patient portal of their EMR. Patients in the usual care (UC) group continue to receive routine medical care from their health care team. The primary outcome is percent weight change from baseline. Study implementation is guided by the Consolidated Framework for Implementation Research (CFIR) and the Reach, Effectiveness, Adoption, Implementation and Maintenance (RE-AIM) evaluative framework.

RESULTS

Patient recruitment began on August 31, 2022 and was completed on January 22, 2024. During the ∼17-month recruitment period, 352 patients were recruited and randomized (176 to ILI; 176 to UC).

CONCLUSION

The results of this study will provide evidence on the effectiveness of a remotely delivered high-intensity weight loss program within a large health care organization, and provide important information regarding its implementation in a digital medicine setting.

CLINICAL TRIALS REGISTRATION NUMBER

NCT05523375.

The CALERIE Genomic Data Resource

Caloric restriction (CR) slows biological aging and prolongs healthy lifespan in model organisms. Findings from the CALERIE randomized, controlled trial of long-term CR in healthy, nonobese humans broadly supports a similar pattern of effects in humans. To expand our understanding of the molecular pathways and biological processes underpinning CR effects in humans, we generated a series of genomic datasets from stored biospecimens collected from n = 218 participants during the trial. These data constitute a genomic data resource for a randomized controlled trial of an intervention targeting the biology of aging. Datasets include whole-genome single-nucleotide polymorphism genotypes, and three-timepoint-longitudinal DNA methylation, mRNA and small RNA datasets generated from blood, skeletal muscle and adipose tissue samples (total sample n = 2,327). The CALERIE Genomic Data Resource described in this article is available from the Aging Research Biobank. This multi-tissue, multi-omics, longitudinal data resource has great potential to advance translational geroscience. ClinicalTrials.gov registration: NCT00427193 .

A 2-year calorie restriction intervention reduces glycomic biological age biomarkers

Background/Objective

In a subset of participants from the CALERIE™ Phase 2 study we evaluated the effects of 2y of ~25% Calorie Restriction (CR) diet on IgG N-glycosylation (GlycAge), plasma and complement C3 N-glycome as markers of aging and inflammaging.

Methods

Plasma samples from 26 participants in the CR group who completed the CALERIE2 trial and were deemed adherent to the intervention (~>10 % CR at 12 mo) were obtained from the NIA AgingResearchBiobank. Glycomic investigations using UPLC or LC-MS analyses were conducted on samples from baseline (BL), mid-intervention (12 mo) and post-intervention (24 mo), and changes resulting from the 2y CR intervention were examined. In addition, anthropometric, clinical, metabolic, DNA methylation (epigenetic) and skeletal muscle transcriptomic data were analyzed to identify aging-related changes that occurred in tandem with the N-glycome changes.

Results

Following the 2y CR intervention, IgG galactosylation was higher at 24mo compared to BL (p = 0.051), digalactosylation and GlycAge (the IgG-based surrogate for biological age) were not different between BL and 12mo or BL and 24mo, but increased between 12mo and 24mo (p = 0.016, 0.027 respectively). GlycAge was also positively associated with TNF-α and ICAM-1 (p=0.030, p=0.017 respectively). Plasma highly branched glycans were decreased by the 2y intervention (BL vs 24 mo: p=0.013), but both plasma and IgG bisecting GlcNAcs were increased (BL vs 24mo: p<0.001, p = 0.01 respectively). Furthermore, total complement C3 protein concentrations were reduced (BL vs 24mo: p <0.001), as were Man9 glycoforms (BL vs 24mo: p<0.001), and Man10 (which is glucosylated) C3 glycoforms (BL vs 24mo: p = 0.046).

Conclusions

24-mos of CR was associated with several favorable, anti-aging, anti-inflammatory changes in the glycome: increased galactosylation, reduced branching glycans, and reduced GlycAge. These promising CR effects were accompanied by an increase in bisecting GlcNAc, a known pro-inflammatory biomarker. These intriguing findings linking CR, clinical, and glycomic changes may be anti-aging and inflammatory, and merit additional investigation.

Intermittent fasting for systemic triglyceride metabolic reprogramming (IFAST): Design and methods of a prospective, randomized, controlled trial

BACKGROUND

Caloric restriction prolongs lifespan in model organisms and improves metrics of aging-related diseases in humans, but daily compliance is challenging. Intermittent fasting improves metrics of lipid and glucose metabolism in the setting of weight loss but whether these metrics are improved independent of weight loss is not known.

METHODS

We seek to address this gap with IFAST, a single-center, three-arm, prospective, randomized, controlled clinical trial. Eligible study participants are adults with no chronic medical conditions beyond prediabetes or overweight but who are at high risk for type 2 diabetes mellitus (T2D), defined as having a history of gestational diabetes or a first-degree relative with T2D. Participants will be randomized in a 1:2:2 schema to either a control group, a fasting group, or a fasting/weight maintenance group. The fasting groups will complete a 24-h fast one day per week for 12 weeks. The key mechanistic endpoint is change in triglyceride composition (defined by carbon content and degree of saturation) as measured by longitudinal metabolomics. The key safety endpoint is percent change from baseline in bone volume fraction (BV/TV; high-resolution peripheral quantitative CT) at the radius in the fasting group. Secondary endpoints include measures of insulin sensitivity (hyperinsulinemic-euglycemic clamp), clinical lipid profiling, systemic inflammation markers, hunger assessment, bone density, and bone microarchitecture with high-resolution peripheral quantitative CT.

CONCLUSION

IFAST will investigate intrinsic metabolic benefits of intermittent fasting beyond weight loss.

TRIAL REGISTRATION

ClinicalTrials.gov ID NCT05722873.

Prediction of individual weight loss using supervised learning: findings from the CALERIETM 2 study

BACKGROUND

Predicting individual weight loss (WL) responses to lifestyle interventions is challenging but might help practitioners and clinicians select the most promising approach for each individual.

OBJECTIVE

The primary aim of this study was to develop machine learning (ML) models to predict individual WL responses using only variables known before starting the intervention. In addition, we used ML to identify pre-intervention variables influencing the individual WL response.

METHODS

We used 12-mo data from the comprehensive assessment of long-term effects of reducing intake of energy (CALERIETM) phase 2 study, which aimed to analyze the long-term effects of caloric restriction on human longevity. On the basis of the data from 130 subjects in the intervention group, we developed classification models to predict binary ("Success" and "No/low success") or multiclass ("High success," "Medium success," and "Low/no success") WL outcomes. Additionally, regression models were developed to predict individual weight change (percent). Models were evaluated on the basis of accuracy, sensitivity, specificity (classification models), and root mean squared error (RMSE; regression models).

RESULTS

Best classification models used 20-40 predictors and achieved 89%-97% accuracy, 91%-100% sensitivity, and 56%-86% specificity for binary classification. For multiclass classification, accuracy (69%) and sensitivity (50%) tended to be lower. The best regression performance was obtained with 36 variables with an RMSE of 2.84%. Among the 21 variables predicting individual weight change most consistently, we identified 2 novel predictors, namely orgasm satisfaction and sexual behavior/experience. Other common predictors have previously been associated with WL (16) or are already used in traditional prediction models (3).

CONCLUSIONS

The prediction models could be implemented by practitioners and clinicians to support the decision of whether lifestyle interventions are sufficient or more aggressive interventions are needed for a given individual, thereby supporting better, faster, data-driven, and unbiased decisions. The CALERIETM phase 2 study was registered at clinicaltrials.gov as NCT00427193.

Regulatory Mechanisms of Aging Through the Nutritional and Metabolic Control of Amino Acid Signaling in Model Organisms

Life activities are supported by the intricate metabolic network that is fueled by nutrients. Nutritional and genetic studies in model organisms have determined that dietary restriction and certain mutations in the insulin signaling pathway lead to lifespan extension. Subsequently, the detailed mechanisms of aging as well as various nutrient signaling pathways and their relationships have been investigated in a wide range of organisms, from yeast to mammals. This review summarizes the roles of nutritional and metabolic signaling in aging and lifespan with a focus on amino acids, the building blocks of organisms. We discuss how lifespan is affected by the sensing, transduction, and metabolism of specific amino acids and consider the influences of life stage, sex, and genetic background on the nutritional control of aging. Our goal is to enhance our understanding of how nutrients affect aging and thus contribute to the biology of aging and lifespan.

Calorie restriction activates a gastric Notch-FOXO1 pathway to expand ghrelin cells

Calorie restriction increases lifespan. Among the tissue-specific protective effects of calorie restriction, the impact on the gastrointestinal tract remains unclear. We report increased numbers of chromogranin A-positive (+), including orexigenic ghrelin+ cells, in the stomach of calorie-restricted mice. This effect was accompanied by increased Notch target Hes1 and Notch ligand Jag1 and was reversed by blocking Notch with DAPT, a gamma-secretase inhibitor. Primary cultures and genetically modified reporter mice show that increased endocrine cell abundance is due to altered Lgr5+ stem and Neurog3+ endocrine progenitor cell proliferation. Different from the intestine, calorie restriction decreased gastric Lgr5+ stem cells, while increasing a FOXO1/Neurog3+ subpopulation of endocrine progenitors in a Notch-dependent manner. Further, activation of FOXO1 was sufficient to promote endocrine cell differentiation independent of Notch. The Notch inhibitor PF-03084014 or ghrelin receptor antagonist GHRP-6 reversed the phenotypic effects of calorie restriction in mice. Tirzepatide additionally expanded ghrelin+ cells in mice. In summary, calorie restriction promotes Notch-dependent, FOXO1-regulated gastric endocrine cell differentiation.

Effect of nuts on lipid profile and inflammatory biomarkers in atherosclerotic cardiovascular disease: a systematic review and meta-analysis of randomized controlled trials

PURPOSE

Nut-enriched diets are related to improve lipid and inflammatory biomarkers in meta-analyses in the context of primary cardiovascular prevention. However, primary studies on secondary cardiovascular prevention are scarce and controversial. This systematic review and meta-analysis aimed to evaluate the effect of nut supplementation on lipid and inflammatory profiles in individuals with atherosclerotic cardiovascular disease, and the frequency of adverse events.

METHODS

Six databases were used for research: PubMed, EMBASE, BVS, Cochrane Library, Web of Science, and ClinicalTrials.gov, until February 2023, with no language restrictions. We performed random-effects meta-analyses to compare nut-enriched diets vs. control diets for pre-post intervention changes. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system assessed the evidence's certainty.

RESULTS

From the 5187 records identified, eight publications containing data referring to five randomized clinical trials involving 439 participants were included in the final analyses. The nuts evaluated were almonds, pecans, Brazil nuts, and mixed nuts, with doses ranging between 5 g and 85 g (median: 30 g/day). The intervention time varied between 6 and 12 weeks. Compared to nut-free diets, nut intake did not have a statistically significant effect on lipid profile biomarkers, except on the atherogenic index (MD: -0.32 [95% CI -0.58 to -0.06], I2 = 0% - moderate certainty of the evidence). Similarly, there was no effect of nuts on inflammatory profile biomarkers. It was not possible to aggregate data on adverse events.

CONCLUSIONS

Nut supplementation did not change lipid and inflammatory profiles in the secondary cardiovascular prevention setting.

Long-Term Randomized Controlled Trials of Diet Intervention Reports and Their Impact on Cancer: A Systematic Review

BACKGROUND

Most randomized controlled trials (RCTs) assessing the impact of diet on cancer have been short term (<1 year), mostly evaluating breast cancer survivors. Given the many-year interval that is generally required for an intervention to have an impact on cancer risk or prognosis, as well as the fact that lifestyle strategies such as diet modification frequently fail due to lack of adherence over the long term, we focused this systematic review only on longer-term (≥1 year) intervention reports. Diet intervention reports focused on reducing cancer risk in overweight and obese individuals target caloric restriction (every day, some days, or most hours of each day).

METHODS

This study is a systematic review of RCTs lasting at least 1 year, testing dietary interventions with a primary or secondary endpoint of cancer or a biomarker linked to cancer.

RESULTS

Fifty-one reports met our review criteria. Twenty of fifty-one (39%) reports are RCTs where the primary endpoint was cancer or a cancer-related biomarker, while the other reports evaluated reports where cancer or a cancer-related biomarker was a secondary endpoint. Thirteen of twenty (65%) primary reports evaluated isocaloric, and the remaining eight evaluated low-calorie diets. All but one of the primary and two secondary isocaloric diet reports evaluated the benefit of a low-fat diet (LFD), with the other three evaluating a Mediterranean diet (MedD). More LCD vs. isocaloric diet primary reports (71% vs. 38%) demonstrated cancer or cancer-related biomarker benefit; the difference in chance of benefit with secondary reports was 85% for LCD vs. 73% for isocaloric diets. Three of three MedD reports demonstrated benefit. Sixty-nine percent (20/29) of the secondary reports came from two large reports: the WHI diet modification trial (15 secondary reports) and the polyp prevention trial (5 secondary reports). Nineteen of twenty-two (86%) primary reports enrolled only women, and three enrolled both men and women. No study that met our criteria enrolled only men, comprising 1447 men in total vs. 62,054 women. Fifteen of twenty (75%) primary reports focus on healthy women or women with breast cancer. Adherence findings are discussed when provided.

CONCLUSIONS

More long-term RCTs evaluating cancer and cancer-related biomarker endpoints are needed, especially for cancers at sites other than the breast.

The Influence of Non-Pharmacological and Pharmacological Interventions on the Course of Autosomal Dominant Polycystic Kidney Disease

Polycystic kidney disease (PKD) includes autosomal dominant (ADPKD) and autosomal recessive (ARPKD) forms, both of which are primary genetic causes of kidney disease in adults and children. ADPKD is the most common hereditary kidney disease, with a prevalence of 329 cases per million in Europe. This condition accounts for 5-15% of end-stage chronic kidney disease (ESKD) cases, and in developed countries such as Poland, 8-10% of all dialysis patients have ESKD due to ADPKD. The disease is caused by mutations in the PKD1 and PKD2 genes, with PKD1 mutations responsible for 85% of cases, leading to a more aggressive disease course. Recent research suggests that ADPKD involves a metabolic defect contributing to cystic epithelial proliferation and cyst growth. Aim: This review explores the interplay between metabolism, obesity, and ADPKD, discussing dietary and pharmacological strategies that target these metabolic abnormalities to slow disease progression. Conclusion: Metabolic reprogramming therapies, including GLP-1 analogs and dual agonists of GIP/GLP-1 or glucagon/GLP-1 receptors, show promise, though further research is needed to understand their potential in ADPKD treatment fully.

Age-associated changes in innate and adaptive immunity: role of the gut microbiota

Aging is generally regarded as an irreversible process, and its intricate relationship with the immune system has garnered significant attention due to its profound implications for the health and well-being of the aging population. As people age, a multitude of alterations occur within the immune system, affecting both innate and adaptive immunity. In the realm of innate immunity, aging brings about changes in the number and function of various immune cells, including neutrophils, monocytes, and macrophages. Additionally, certain immune pathways, like the cGAS-STING, become activated. These alterations can potentially result in telomere damage, the disruption of cytokine signaling, and impaired recognition of pathogens. The adaptive immune system, too, undergoes a myriad of changes as age advances. These include shifts in the number, frequency, subtype, and function of T cells and B cells. Furthermore, the human gut microbiota undergoes dynamic changes as a part of the aging process. Notably, the interplay between immune changes and gut microbiota highlights the gut's role in modulating immune responses and maintaining immune homeostasis. The gut microbiota of centenarians exhibits characteristics akin to those found in young individuals, setting it apart from the microbiota observed in typical elderly individuals. This review delves into the current understanding of how aging impacts the immune system and suggests potential strategies for reversing aging through interventions in immune factors.

Effects of Different Exercises Combined with Different Dietary Interventions on Body Composition: A Systematic Review and Network Meta-Analysis

BACKGROUND

Exercise and dietary interventions are essential for maintaining weight and reducing fat accumulation. With the growing popularity of various dietary strategies, evidence suggests that combining exercise with dietary interventions offers greater benefits than either approach alone. Consequently, this combined strategy has become a preferred method for many individuals aiming to maintain health. Calorie restriction, 5/2 intermittent fasting, time-restricted feeding, and the ketogenic diet are among the most popular dietary interventions today. Aerobic exercise, resistance training, and mixed exercise are the most widely practiced forms of physical activity. Exploring the best combinations of these approaches to determine which yields the most effective results is both meaningful and valuable. Despite this trend, a comparative analysis of the effects of different exercise and diet combinations is lacking. This study uses network meta-analysis to evaluate the impact of various combined interventions on body composition and to compare their efficacy.

METHODS

We systematically reviewed literature from database inception through May 2024, searching PubMed, Web of Science, Embase, and the Cochrane Library. The study was registered in PROSPERO under the title: "Effects of Exercise Combined with Different Dietary Interventions on Body Composition: A Systematic Review and Network Meta-Analysis" (identifier: CRD42024542184). Studies were meticulously selected based on specific inclusion and exclusion criteria (The included studies must be randomized controlled trials involving healthy adults aged 18 to 65 years. Articles were rigorously screened according to the specified inclusion and exclusion criteria.), and their risk of bias was assessed using the Cochrane risk of bias tool. Data were aggregated and analyzed using network meta-analysis, with intervention efficacy ranked by Surface Under the Cumulative Ranking (SUCRA) curves.

RESULTS

The network meta-analysis included 78 randomized controlled trials with 5219 participants, comparing the effects of four combined interventions: exercise with calorie restriction (CR+EX), exercise with time-restricted eating (TRF+EX), exercise with 5/2 intermittent fasting (5/2F+EX), and exercise with a ketogenic diet (KD+EX) on body composition. Intervention efficacy ranking was as follows: (1) Weight Reduction: CR+EX > KD+EX > TRF+EX > 5/2F+EX (Relative to CR+EX, the effect sizes of 5/2F+EX, TRF+EX and KD+EX are 2.94 (-3.64, 9.52); 2.37 (-0.40, 5.15); 1.80 (-1.75, 5.34)). (2) BMI: CR+EX > KD+EX > 5/2F+EX > TRF+EX (Relative to CR+EX, the effect sizes of 5/2F+EX, TRF+EX and KD+EX are 1.95 (-0.49, 4.39); 2.20 (1.08, 3.32); 1.23 (-0.26, 2.71)). (3) Body Fat Percentage: CR+EX > 5/2F+EX > TRF+EX > KD+EX (Relative to CR+EX, the effect sizes of 5/2F+EX, TRF+EX and KD+EX are 2.66 (-1.56, 6.89); 2.84 (0.56, 5.13); 3.14 (0.52, 5.75).). (4) Lean Body Mass in Male: CR+EX > TRF+EX > KD+EX (Relative to CR+EX, the effect sizes of TRF+EX and KD+EX are -1.60 (-6.98, 3.78); -2.76 (-7.93, 2.40)). (5) Lean Body Mass in Female: TRF+EX > CR+EX > 5/2F+EX > KD+EX (Relative to TRF+EX, the effect sizes of CR+EX, 5/2F+EX and KD+EX are -0.52 (-2.58, 1.55); -1.83 (-4.71, 1.04); -2.46 (-5.69,0.76).).

CONCLUSION

Calorie restriction combined with exercise emerged as the most effective strategy for reducing weight and fat percentage while maintaining lean body mass. For women, combining exercise with time-restricted eating proved optimal for preserving muscle mass. While combining exercise with a ketogenic diet effectively reduces weight, it is comparatively less effective at decreasing fat percentage and preserving lean body mass. Hence, the ketogenic diet combined with exercise is considered suboptimal.

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.

Molecular Mechanisms of Healthy Aging: The Role of Caloric Restriction, Intermittent Fasting, Mediterranean Diet, and Ketogenic Diet-A Scoping Review

As the population ages, promoting healthy aging through targeted interventions becomes increasingly crucial. Growing evidence suggests that dietary interventions can significantly impact this process by modulating fundamental molecular pathways. This review focuses on the potential of targeted dietary strategies in promoting healthy aging and the mechanisms by which specific nutrients and dietary patterns influence key pathways involved in cellular repair, inflammation, and metabolic regulation. Caloric restriction, intermittent fasting, the Mediterranean diet, as well as the ketogenic diet showed promising effects on promoting healthy aging, possibly by modulating mTORC1 AMPK, an insulin signaling pathway. By understanding the intricate interplay between diet and molecular pathways, we can develop personalized dietary strategies that not only prevent age-related diseases, but also promote overall health and well-being throughout the aging process.

Secondary integrated analysis of multi-tissue transcriptomic responses to a combined lifestyle intervention in older adults from the GOTO nonrandomized trial

Molecular effects of lifestyle interventions are typically studied in a single tissue. Here, we perform a secondary analysis on the sex-specific effects of the Growing Old TOgether trial (GOTO, trial registration number GOT NL3301 ( https://onderzoekmetmensen.nl/nl/trial/27183 ), NL-OMON27183 , primary outcomes have been previously reported in ref. 1), a moderate 13-week combined lifestyle intervention on the transcriptomes of postprandial blood, subcutaneous adipose tissue (SAT) and muscle tissue in healthy older adults, the overlap in effect between tissues and their relation to whole-body parameters of metabolic health. The GOTO intervention has virtually no effect on the postprandial blood transcriptome, while the SAT and muscle transcriptomes respond significantly. In SAT, pathways involved in HDL remodeling, O2/CO2 exchange and signaling are overrepresented, while in muscle, collagen and extracellular matrix pathways are significantly overexpressed. Additionally, we find that the effects of the SAT transcriptome closest associates with gains in metabolic health. Lastly, in males, we identify a shared variation between the transcriptomes of the three tissues. We conclude that the GOTO intervention has a significant effect on metabolic and muscle fibre pathways in the SAT and muscle transcriptome, respectively. Aligning the response in the three tissues revealed a blood transcriptome component which may act as an integrated health marker for metabolic intervention effects across tissues.

Can caloric restriction improve outcomes of elective surgeries?

Energy restriction (ER) is a nutrition method to reduce the amount of energy intake while maintaining adequate nutrition. In clinical medicine, applications of ER have been implicated in longevity, mortality, metabolic, immune, and psychological health. However, there are limited studies showing the clinical benefit of ER within the immediate surgical setting. A specific, clinically oriented summary of the potential applications of ER is needed to optimize surgery outcomes for patients. The purpose of this article is to examine how ER can be used for perioperative optimization to improve outcomes for the patient and surgeon. It will also explore how these outcomes can feasibly fit in with enhanced recovery after surgery protocols and can be used as a method for nutrition optimization in surgery. Despite evidence of caloric restriction improving outcomes in critically ill surgical patients, there is not enough evidence to conclude that ER, perioperatively across noncritically ill cohorts, improves postoperative morbidity and mortality in elective surgeries. Nevertheless, a contemporary account of how ER techniques may have a significant role in reducing risk factors of adverse surgical outcomes in this cohort, for example, by encouraging preoperative weight loss contributing to decreased operating times, is reviewed.

Principal component-based clinical aging clocks identify signatures of healthy aging and targets for clinical intervention

Clocks that measure biological age should predict all-cause mortality and give rise to actionable insights to promote healthy aging. Here we applied dimensionality reduction by principal component analysis to clinical data to generate a clinical aging clock (PCAge) identifying signatures (principal components) separating healthy and unhealthy aging trajectories. We found signatures of metabolic dysregulation, cardiac and renal dysfunction and inflammation that predict unsuccessful aging, and we demonstrate that these processes can be impacted using well-established drug interventions. Furthermore, we generated a streamlined aging clock (LinAge), based directly on PCAge, which maintains equivalent predictive power but relies on substantially fewer features. Finally, we demonstrate that our approach can be tailored to individual datasets, by re-training a custom clinical clock (CALinAge), for use in the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE) study of caloric restriction. Our analysis of CALERIE participants suggests that 2 years of mild caloric restriction significantly reduces biological age. Altogether, we demonstrate that this dimensionality reduction approach, through integrating different biological markers, can provide targets for preventative medicine and the promotion of healthy aging.

Thermal facial image analyses reveal quantitative hallmarks of aging and metabolic diseases

Although human core body temperature is known to decrease with age, the age dependency of facial temperature and its potential to indicate aging rate or aging-related diseases remains uncertain. Here, we collected thermal facial images of 2,811 Han Chinese individuals 20-90 years old, developed the ThermoFace method to automatically process and analyze images, and then generated thermal age and disease prediction models. The ThermoFace deep learning model for thermal facial age has a mean absolute deviation of about 5 years in cross-validation and 5.18 years in an independent cohort. The difference between predicted and chronological age is highly associated with metabolic parameters, sleep time, and gene expression pathways like DNA repair, lipolysis, and ATPase in the blood transcriptome, and it is modifiable by exercise. Consistently, ThermoFace disease predictors forecast metabolic diseases like fatty liver with high accuracy (AUC > 0.80), with predicted disease probability correlated with metabolic parameters.

Underlying Mechanisms of the Protective Effects of Lifestyle Factors On Age-Related Diseases

The rise in life expectancy has significantly increased the occurrence of age-related chronic diseases, leading to escalating expenses for both society and individuals. Among the main factors influencing health and lifespan, lifestyle takes a forefront position. Specifically, nutrition, mental activity, and physical exercise influence the molecular and functional mechanisms that contribute to the prevention of major age-related diseases. Gaining deeper insights into the mechanisms that drive the positive effects of healthy lifestyles is valuable for creating interventions to prevent or postpone the development of chronic degenerative diseases. This review summarizes the main mechanisms that underlie the positive effect of lifestyle factors in counteracting the major age-related diseases involving brain health, musculoskeletal function, cancer, frailty, and cardiovascular diseases, among others. This knowledge will help to identify high-risk populations for targeted intervention trials and discover new biomarkers associated with healthy aging.

Adiposity, immunity, and inflammation: interrelationships in health and disease: a report from 24th Annual Harvard Nutrition Obesity Symposium, June 2023

The rapidly evolving field of immunometabolism explores how changes in local immune environments may affect key metabolic and cellular processes, including that of adipose tissue. Importantly, these changes may contribute to low-grade systemic inflammation. In turn, chronic low-grade inflammation affecting adipose tissue may exacerbate the outcome of metabolic diseases. Novel advances in our understanding of immunometabolic processes may critically lead to interventions to reduce disease severity and progression. An important example in this regard relates to obesity, which has a multifaceted effect on immunity, activating the proinflammatory pathways such as the inflammasome and disrupting cellular homeostasis. This multifaceted effect of obesity can be investigated through study of downstream conditions using cellular and systemic investigative techniques. To further explore this field, the National Institutes of Health P30 Nutrition Obesity Research Center at Harvard, in partnership with Harvard Medical School, assembled experts to present at its 24th Annual Symposium entitled "Adiposity, Immunity, and Inflammation: Interrelationships in Health and Disease" on 7 June, 2023. This manuscript seeks to synthesize and present key findings from the symposium, highlighting new research and novel disease-specific advances in the field. Better understanding the interaction between metabolism and immunity offers promising preventative and treatment therapies for obesity-related immunometabolic diseases.

Effect of long-term caloric restriction on telomere length in healthy adults: CALERIE™ 2 trial analysis

Caloric restriction (CR) modifies lifespan and aging biology in animal models. The Comprehensive Assessment of Long-Term Effects of Reducing Intake of Energy (CALERIE™) 2 trial tested translation of these findings to humans. CALERIE™ randomized healthy, nonobese men and premenopausal women (age 21-50y; BMI 22.0-27.9 kg/m2), to 25% CR or ad-libitum (AL) control (2:1) for 2 years. Prior analyses of CALERIE™ participants' blood chemistries, immunology, and epigenetic data suggest the 2-year CR intervention slowed biological aging. Here, we extend these analyses to test effects of CR on telomere length (TL) attrition. TL was quantified in blood samples collected at baseline, 12-, and 24-months by quantitative PCR (absolute TL; aTL) and a published DNA-methylation algorithm (DNAmTL). Intent-to-treat analysis found no significant differences in TL attrition across the first year, although there were trends toward increased attrition in the CR group for both aTL and DNAmTL measurements. When accounting for adherence heterogeneity with an Effect-of-Treatment-on-the-Treated analysis, greater CR dose was associated with increased DNAmTL attrition during the baseline to 12-month weight-loss period. By contrast, both CR group status and increased CR were associated with reduced aTL attrition over the month 12 to month 24 weight maintenance period. No differences were observed when considering TL change across the study duration from baseline to 24-months, leaving it unclear whether CR-related effects reflect long-term detriments to telomere fidelity, a hormesis-like adaptation to decreased energy availability, or measurement error and insufficient statistical power. Unraveling these trends will be a focus of future CALERIE™ analyses and trials.

Physiology of the weight-loss plateau in response to diet restriction, GLP-1 receptor agonism, and bariatric surgery

OBJECTIVE

The objective of this study was to investigate why different weight-loss interventions result in varying durations of weight loss prior to approaching plateaus.

METHODS

A validated mathematical model of energy metabolism and body composition dynamics was used to simulate mean weight- and fat-loss trajectories in response to diet restriction, semaglutide 2.4 mg, tirzepatide 10 mg, and Roux-en-Y gastric bypass (RYGB) surgery interventions. Each intervention was simulated by adjusting two model parameters affecting energy intake to fit the mean weight-loss data. One parameter represented the persistent shift of the system from baseline equilibrium, and the other parameter represented the strength of the feedback control circuit relating weight loss to increased appetite.

RESULTS

RYGB surgery resulted in a persistent intervention magnitude more than threefold greater than diet restriction and about double that of tirzepatide and semaglutide. All interventions except diet restriction substantially weakened the appetite feedback control circuit, resulting in an extended period of weight loss prior to the plateau.

CONCLUSIONS

These preliminary mathematical modeling results suggest that both glucagon-like peptide 1 (GLP-1) receptor agonism and RYGB surgery interventions act to weaken the appetite feedback control circuit that regulates body weight and induce greater persistent effects to shift the body weight equilibrium compared with diet restriction.

Adipose tissue as a linchpin of organismal ageing

Ageing is a conserved biological process, modulated by intrinsic and extrinsic factors, that leads to changes in life expectancy. In humans, ageing is characterized by greatly increased prevalence of cardiometabolic disease, type 2 diabetes and disorders associated with impaired immune surveillance. Adipose tissue displays species-conserved, temporal changes with ageing, including redistribution from peripheral to central depots, loss of thermogenic capacity and expansion within the bone marrow. Adipose tissue is localized to discrete depots, and also diffusely distributed within multiple organs and tissues in direct proximity to specialized cells. Thus, through their potent endocrine properties, adipocytes are capable of modulating tissue and organ function throughout the body. In addition to adipocytes, multipotent progenitor/stem cells in adipose tissue play a crucial role in maintenance and repair of tissues throughout the lifetime. Adipose tissue may therefore be a central driver for organismal ageing and age-associated diseases. Here we review the features of adipose tissue during ageing, and discuss potential mechanisms by which these changes affect whole-body metabolism, immunity and longevity. We also explore the potential of adipose tissue-targeted therapies to ameliorate age-associated disease burdens.

Independent and combined effects of calorie restriction and AICAR on glucose uptake and insulin signaling in skeletal muscles from 24-month-old female and male rats

We assessed the effects of two levels of calorie restriction (CR; eating either 15% or 35% less than ad libitum, AL, food intake for 8 weeks) by 24-month-old female and male rats on glucose uptake (GU) and phosphorylation of key signaling proteins (Akt; AMP-activated protein kinase, AMPK; Akt substrate of 160 kDa, AS160) measured in isolated skeletal muscles that underwent four incubation conditions (without either insulin or AICAR, an AMPK activator; with AICAR alone; with insulin alone; or with insulin and AICAR). Regardless of sex: (1) neither CR group versus the AL group had greater GU by insulin-stimulated muscles; (2) phosphorylation of Akt in insulin-stimulated muscles was increased in 35% CR versus AL rats; (3) prior AICAR treatment of muscle resulted in greater GU by insulin-stimulated muscles, regardless of diet; and (4) AICAR caused elevated phosphorylation of acetyl CoA carboxylase, an indicator of AMPK activation, in all diet groups. There was a sexually dimorphic diet effect on AS160 phosphorylation, with 35% CR exceeding AL for insulin-stimulated muscles in male rats, but not in female rats. Our working hypothesis is that the lack of a CR-effect on GU by insulin-stimulated muscles was related to the extended duration of the ex vivo incubation period (290 min compared to 40-50 min that was previously reported to be effective). The observed efficacy of prior treatment of muscles with AICAR to improve glucose uptake in insulin-stimulated muscles supports the strategy of targeting AMPK with the goal of improving insulin sensitivity in older females and males.

Nutrient-epigenome interactions: Implications for personalized nutrition against aging-associated diseases

Aging is a multifaceted process involving genetic and environmental interactions often resulting in epigenetic changes, potentially leading to aging-related diseases. Various strategies, like dietary interventions and calorie restrictions, have been employed to modify these epigenetic landscapes. A burgeoning field of interest focuses on the role of microbiota in human health, emphasizing system biology and computational approaches. These methods help decipher the intricate interplay between diet and gut microbiota, facilitating the creation of personalized nutrition strategies. In this review, we analysed the mechanisms related to nutritional interventions while highlighting the influence of dietary strategies, like calorie restriction and intermittent fasting, on microbial composition and function. We explore how gut microbiota affects the efficacy of interventions using tools like multi-omics data integration, network analysis, and machine learning. These tools enable us to pinpoint critical regulatory elements and generate individualized models for dietary responses. Lastly, we emphasize the need for a deeper comprehension of nutrient-epigenome interactions and the potential of personalized nutrition informed by individual genetic and epigenetic profiles. As knowledge and technology advance, dietary epigenetics stands on the cusp of reshaping our strategy against aging and related diseases.

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.

Healthy Aging in Times of Extreme Temperatures: Biomedical Approaches

Climate extremes and rising energy prices present interconnected global health risks. Technical solutions can be supplemented with biomedical approaches to promote healthy longevity in hot and cold conditions. In summer, reducing basal metabolic rate through mild caloric restriction or CR mimetics, such as resveratrol, can potentially be used to lower body temperature. In winter, activating brown adipose tissue (BAT) for non-shivering thermogenesis and improved metabolic health can help adaptation to colder environments. Catechins found in green tea and in other food could be alternatives to drugs for these purposes. This review examines and discusses the biomedical evidence supporting the use of CR mimetics and BAT activators for health benefits amid increasingly extreme temperatures.

The effects of popular diets on bone health in the past decade: a narrative review

Bone health encompasses not only bone mineral density but also bone architecture and mechanical properties that can impact bone strength. While specific dietary interventions have been proposed to treat various diseases such as obesity and diabetes, their effects on bone health remain unclear. The aim of this review is to examine literature published in the past decade, summarize the effects of currently popular diets on bone health, elucidate underlying mechanisms, and provide solutions to neutralize the side effects. The diets discussed in this review include a ketogenic diet (KD), a Mediterranean diet (MD), caloric restriction (CR), a high-protein diet (HP), and intermittent fasting (IF). Although detrimental effects on bone health have been noticed in the KD and CR diets, it is still controversial, while the MD and HP diets have shown protective effects, and the effects of IF diets are still uncertain. The mechanism of these effects and the attenuation methods have gained attention and have been discussed in recent years: the KD diet interrupts energy balance and calcium metabolism, which reduces bone quality. Ginsenoside-Rb2, metformin, and simvastatin have been shown to attenuate bone loss during KD. The CR diet influences energy imbalance, glucocorticoid levels, and adipose tissue, causing bone loss. Adequate vitamin D and calcium supplementation and exercise training can attenuate these effects. The olive oil in the MD may be an effective component that protects bone health. HP diets also have components that protect bone health, but their mechanism requires further investigation. In IF, animal studies have shown detrimental effects on bone health, while human studies have not. Therefore, the effects of diets on bone health vary accordingly.

Liver-derived plasminogen mediates muscle stem cell expansion during caloric restriction through the plasminogen receptor Plg-RKT

An intriguing effect of short-term caloric restriction (CR) is the expansion of certain stem cell populations, including muscle stem cells (satellite cells), which facilitate an accelerated regenerative program after injury. Here, we utilized the MetRSL274G (MetRS) transgenic mouse to identify liver-secreted plasminogen as a candidate for regulating satellite cell expansion during short-term CR. Knockdown of circulating plasminogen prevents satellite cell expansion during short-term CR. Furthermore, loss of the plasminogen receptor KT (Plg-RKT) is also sufficient to prevent CR-related satellite cell expansion, consistent with direct signaling of plasminogen through the plasminogen receptor Plg-RKT/ERK kinase to promote proliferation of satellite cells. Importantly, we are able to replicate many of these findings in human participants from the CALERIE trial. Our results demonstrate that CR enhances liver protein secretion of plasminogen, which signals directly to the muscle satellite cell through Plg-RKT to promote proliferation and subsequent muscle resilience during CR.

Dietary approaches for exploiting metabolic vulnerabilities in cancer

Renewed interest in tumor metabolism sparked an enthusiasm for dietary interventions to prevent and treat cancer. Changes in diet impact circulating nutrient levels in the plasma and the tumor microenvironment, and preclinical studies suggest that dietary approaches, including caloric and nutrient restrictions, can modulate tumor initiation, progression, and metastasis. Cancers are heterogeneous in their metabolic dependencies and preferred energy sources and can be addicted to glucose, fructose, amino acids, or lipids for survival and growth. This dependence is influenced by tumor type, anatomical location, tissue of origin, aberrant signaling, and the microenvironment. This review summarizes nutrient dependencies and the related signaling pathway activations that provide targets for nutritional interventions. We examine popular dietary approaches used as adjuvants to anticancer therapies, encompassing caloric restrictions, including time-restricted feeding, intermittent fasting, fasting-mimicking diets (FMDs), and nutrient restrictions, notably the ketogenic diet. Despite promising results, much of the knowledge on dietary restrictions comes from in vitro and animal studies, which may not accurately reflect real-life situations. Further research is needed to determine the optimal duration, timing, safety, and efficacy of dietary restrictions for different cancers and treatments. In addition, well-designed human trials are necessary to establish the link between specific metabolic vulnerabilities and targeted dietary interventions. However, low patient compliance in clinical trials remains a significant challenge.

Requirements for essential micronutrients during caloric restriction and fasting

Caloric restriction (CR) or energy restriction, when carefully designed, monitored, and implemented in self-motivated and compliant individuals, proves to be a viable non-pharmacologic strategy for human weight control and obesity management. Beyond its role in weight management, CR has the potential to impede responses involved not only in the pathogenesis of various diseases but also in the aging process in adults, thereby being proposed to promote a healthier and longer life. The core objective of implementing caloric restriction is to establish a balance between energy intake and expenditure, typically involving a reduction in intake and an increase in expenditure-a negative balance at least initially. It may transition toward and maintain a more desired equilibrium over time. However, it is essential to note that CR may lead to a proportional reduction in micronutrient intake unless corresponding supplementation is provided. Historical human case reports on CR have consistently maintained adequate intakes (AI) or recommended dietary allowances (RDA) for essential micronutrients, including vitamins and minerals. Similarly, longevity studies involving non-human primates have upheld micronutrient consumption levels comparable to control groups or baseline measures. Recent randomized controlled trials (RCTs) have also endorsed daily supplementation of multivitamins and minerals to meet micronutrient needs. However, aside from these human case reports, limited human trials, and primate experiments, there remains a notable gap in human research specifically addressing precise micronutrient requirements during CR. While adhering to AI or RDA for minerals and vitamins appears sensible in the current practice, it's important to recognize that these guidelines are formulated for generally healthy populations under standard circumstances. The adequacy of these guidelines in the setting of prolonged and profound negative energy balance remains unclear. From perspectives of evidence-based medicine and precision nutrition, this field necessitates comprehensive exploration to uncover the intricacies of absorption, utilization, and metabolism and the requirement of each hydrophilic and lipophilic vitamin and mineral during these special periods. Such investigations are crucial to determine whether existing daily dietary recommendations for micronutrients are quantitatively inadequate, excessive, or appropriate when energy balance remains negative over extended durations.

Beneficial effects of simultaneously targeting calorie intake and calorie efficiency in diet-induced obese mice

Semaglutide is an anti-diabetes and weight loss drug that decreases food intake, slows gastric emptying, and increases insulin secretion. Patients begin treatment with low-dose semaglutide and increase dosage over time as efficacy plateaus. With increasing dosage, there is also greater incidence of gastrointestinal side effects. One reason for the plateau in semaglutide efficacy despite continued low food intake is due to compensatory actions whereby the body becomes more metabolically efficient to defend against further weight loss. Mitochondrial uncoupler drugs decrease metabolic efficiency, therefore we sought to investigate the combination therapy of semaglutide with the mitochondrial uncoupler BAM15 in diet-induced obese mice. Mice were fed high-fat western diet (WD) and stratified into six treatment groups including WD control, BAM15, low-dose semaglutide without or with BAM15, and high-dose semaglutide without or with BAM15. Combining BAM15 with either semaglutide dose decreased body fat and liver triglycerides, which was not achieved by any monotherapy, while high-dose semaglutide with BAM15 had the greatest effect on glucose homeostasis. This study demonstrates a novel approach to improve weight loss without loss of lean mass and improve glucose control by simultaneously targeting energy intake and energy efficiency. Such a combination may decrease the need for semaglutide dose escalation and hence minimize potential gastrointestinal side effects.

Antiaging Strategies and Remedies: A Landscape of Research Progress and Promise

Aging is typified by a gradual loss of physiological fitness and accumulation of cellular damage, leading to deteriorated functions and enhanced vulnerability to diseases. Antiaging research has a long history throughout civilization, with many efforts put forth to understand and prevent the effects of aging. Multiple strategies aiming to promote healthy aging and extend the lifespan have been developed including lifestyle adjustments, medical treatments, and social programs. A multitude of antiaging medicines and remedies have also been explored. Here, we use data from the CAS Content Collection to analyze the publication landscape of recent research related to antiaging strategies and treatments. We review the recent advances and delineate trends in research headway of antiaging knowledge and practice across time, geography, and development pipelines. We further assess the state-of-the-art antiaging approaches and explore their correlations with age-related diseases. The landscape of antiaging drugs has been outlined and explored. Well-recognized and novel, currently evaluated antiaging agents have also been summarized. Finally, we review clinical applications of antiaging products with their development pipelines. The objective of this review is to summarize current knowledge on preventive strategies and treatment remedies in the field of aging, to outline challenges and evaluate growth opportunities, in order to further efforts to solve the problems that remain.

Soluble Klotho, a Potential Biomarker of Chronic Kidney Disease-Mineral Bone Disorders Involved in Healthy Ageing: Lights and Shadows

Shortly after the discovery of Klotho, interest grew in its potential role in chronic kidney disease (CKD). There are three isoforms of the Klotho protein: αKlotho, βKlotho and γKlotho. This review will focus on αKlotho due to its relevance as a biomarker in CKD. αKlotho is synthesized mainly in the kidneys, but it can be released into the bloodstream and urine as soluble Klotho (sKlotho), which undertakes systemic actions, independently or in combination with FGF23. It is usually accepted that sKlotho levels are reduced early in CKD and that lower levels of sKlotho might be associated with the main chronic kidney disease-mineral bone disorders (CKD-MBDs): cardiovascular and bone disease. However, as results are inconsistent, the applicability of sKlotho as a CKD-MBD biomarker is still a matter of controversy. Much of the inconsistency can be explained due to low sample numbers, the low quality of clinical studies, the lack of standardized assays to assess sKlotho and a lack of consensus on sample processing, especially in urine. In recent decades, because of our longer life expectancies, the prevalence of accelerated-ageing diseases, such as CKD, has increased. Exercise, social interaction and caloric restriction are considered key factors for healthy ageing. While exercise and social interaction seem to be related to higher serum sKlotho levels, it is not clear whether serum sKlotho might be influenced by caloric restriction. This review focuses on the possible role of sKlotho as a biomarker in CKD-MBD, highlighting the difference between solid knowledge and areas requiring further research, including the role of sKlotho in healthy ageing.

Calorie restriction reduces biomarkers of cellular senescence in humans

Calorie restriction (CR) with adequate nutrient intake is a potential geroprotective intervention. To advance this concept in humans, we tested the hypothesis that moderate CR in healthy young-to-middle-aged individuals would reduce circulating biomarkers of cellular senescence, a fundamental mechanism of aging and aging-related conditions. Using plasma specimens from the Comprehensive Assessment of Long-term Effects of Reducing Intake of Energy (CALERIE™) phase 2 study, we found that CR significantly reduced the concentrations of several senescence biomarkers at 12 and 24 months compared to an ad libitum diet. Using machine learning, changes in biomarker concentrations emerged as important predictors of the change in HOMA-IR and insulin sensitivity index at 12 and 24 months, and the change in resting metabolic rate residual at 12 months. Finally, using adipose tissue RNA-sequencing data from a subset of participants, we observed a significant reduction in a senescence-focused gene set in response to CR at both 12 and 24 months compared to baseline. Our results advance the understanding of the effects of CR in humans and further support a link between cellular senescence and metabolic health.

Impact of Intermittent Fasting and/or Caloric Restriction on Aging-Related Outcomes in Adults: A Scoping Review of Randomized Controlled Trials

Intermittent fasting (IF) and caloric restriction (CR) are dietary strategies to prevent and attenuate obesity associated with conditions and aging-related outcomes. This scoping review examined the cardiometabolic, cancer, and neurocognitive outcome differences between IF and CR interventions among adults. We applied a systematic approach to scope published randomized controlled trials (databases: PubMed, CINAHL Plus, PsychInfo, Scopus, and Google Scholar) from inception through August 2023. The initial search provided 389 unique articles which were critically appraised. Thirty articles met the eligibility criteria for inclusion: 12 were IF, 10 were CR, and 8 were combined IF and CR interventions. IF and CR were associated with weight loss; however, IF studies tended to report greater adherence compared with CR. Overall, IF and CR were equivalently effective across cardiometabolic, cancer, and neurocognitive outcomes. Our findings suggest that IF has health benefits in a variety of conditions and may be better accepted and tolerated than CR, but more comparative research is required.

Energy balance and body composition after switch between integrase strand transfer inhibitors and doravirine among people with HIV

BACKGROUND

Integrase strand transfer inhibitors (INSTIs) are associated with excessive weight gain among a subset of persons with HIV (PWH), due to unclear mechanisms. We assessed energy intake (EI) and expenditure (EE) following switch off and onto INSTIs.

METHODS

PWH with >10% weight gain on an INSTI-based regimen switched INSTI to doravirine for 12 weeks, then back to INSTI for 12 weeks while keeping their remaining regimen stable. Twenty-four-hour EE, EI and weight were measured on INSTI, following switch to doravirine, and upon INSTI restart. Mixed models analysed changes over time.

RESULTS

Among 18 participants, unadjusted 24 h EE decreased by 83 (95% CI -181 to 14) kcal following switch to doravirine, and by 2 (-105 to 100) kcal after INSTI restart; energy balance (EE-EI) increased by 266 (-126 to 658) kcal from Week 0 to Week 12, and decreased by 3 (-429 to 423) kcal from Week 12 to Week 24. Trends toward weight loss occurred following switch to doravirine [mean -1.25 (-3.18 to 0.69) kg] and when back on INSTI [-0.47 (-2.45 to 1.52) kg]. Trunk fat decreased on doravirine [-474 (-1398 to 449) g], with some regain following INSTI restart [199 (-747 to 1145) g]. Fat-free mass decreased on doravirine [-491 (-1399 to 417) g] and increased slightly after INSTI restart [178 (-753 to 1108) g].

CONCLUSIONS

Among PWH with >10% weight gain on an INSTI, switch to doravirine was associated with a trend towards decreases in 24 h EE, weight, trunk fat mass and fat-free mass. Observed changes were not significant, but suggest a mild weight-suppressive effect of doravirine among PWH.

Responses to Many Anti-Aging Interventions Are Sexually Dimorphic

There is increasing appreciation that sex differences are not limited to reproductive organs or traits related to reproduction and that sex is an important biological variable in most characteristics of a living organism. The biological process of aging and aging-related traits are no exception and exhibit numerous, often major, sex differences. This article explores one aspect of these differences, namely sex differences in the responses to anti-aging interventions. Aging can be slowed down and/or postponed by a variety of environmental ("lifestyle"), genetic or pharmacological interventions. Although many, particularly older studies utilized only one sex of experimental animals, there is considerable evidence that responses to these interventions can be very different in females and males. Calorie restriction (CR), that is reducing food intake without malnutrition can extend longevity in both sexes, but specific metabolic alterations and health benefits induced by CR are not the same in women and men. In laboratory mice, several of the genetic alterations that reduce insulin-like growth factor I (IGF-1) signaling extend longevity more effectively in females or in females only. Beneficial effects of rapamycin, an inhibitor of mTOR signaling, on mouse longevity are greater in females. In contrast, several anti-aging compounds, including a weak estrogen, 17 alpha estradiol, extend longevity of male, but not female, mice. Apparently, fundamental mechanisms of aging are not identical in females and males and it is essential to use both sexes in studies aimed at identifying novel anti-aging interventions. Recommendations for lifestyle modifications, drugs, and dietary supplements to maintain good health and functionality into advanced age and to live longer will likely need to be tailored to the sex of the user.

Caloric Restriction Improves Spatial Learning Deficits in Tau Mice

Background

Caloric restriction (CR) has been recognized for its benefits in delaying age-related diseases and extending lifespan. While its effects on amyloid pathology in Alzheimer's disease (AD) mouse models are well-documented, its effects on tauopathy, another hallmark of AD, are less explored.

Objective

To assess the impact of a short-term 30% CR regimen on age-dependent spatial learning deficits and pathological features in a tauopathy mouse model.

Methods

We subjected male PS19 tau P301S (hereafter PS19) and age-matched wildtype mice from two age cohorts (4.5 and 7.5 months old) to a 6-week 30% CR regimen. Spatial learning performance was assessed using the Barnes Maze test. Tau pathology, neuroinflammation, hippocampal cell proliferation, and neurogenesis were evaluated in the older cohort by immunohistochemical staining and RT-qPCR.

Results

CR mitigated age-dependent spatial learning deficits in PS19 mice but exhibited limited effects on tau pathology and the associated neuroinflammation. Additionally, we found a decrease in hippocampal cell proliferation, predominantly of Iba1+ cells.

Conclusions

Our findings reinforce the cognitive benefits conferred by CR despite its limited modulation of disease pathology. Given the pivotal role of microglia in tau-driven pathology, the observed reduction in Iba1+ cells under CR suggests potential therapeutic implications, particularly if CR would be introduced early in disease progression.