Protein Restriction, Epigenetic Diet, Intermittent Fasting as New Approaches for Preventing Age-associated Diseases

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.

Intermittent Fasting Protects Against Age-Induced Rat Benign Prostatic Hyperplasia via Preservation of Prostatic Histomorphology, Modification of Oxidative Stress, and Beclin-1/P62 Pathway

Intermittent fasting (IF) has several beneficial effects on most age-related degenerative changes in the body. Here we aimed to investigate the impact of IF on the biochemical and morphological abnormalities associated with normal aging in rat prostate. Thirty male albino rats were used and divided into three equal groups: adult group, rats aged 3 months; aged group, rats aged 15 months; and IF-aged group, rats aged 15 months maintained on intermittent fasting. After 3 months, prostates were excised and processed for biochemical, histological, and immunohistochemical study. Aging resulted in prostatic histological changes that resemble those of benign prostatic hyperplasia (BPH) with increased malondialdehyde (MDA) level, decreased glutathione (GSH) level, reduction of autophagy, and increased proliferation. Intermittent fasting ameliorated these described age-related prostatic changes. It could be concluded that IF could prevent age-induced BPH. This occurs via its anti-inflammatory and anti-proliferative effects, suppression of oxidative stress, and by improving autophagy via Beclin-1/P62 modulation. These mechanisms underlie the IF-mediated protection against age-related BPH. Because of IF safety and easy availability over BPH medications, it might be promising for managing BPH after further clinical studies.

Effect of dietary protein content shift on aging in elderly rats by comprehensive quantitative score and metabolomics analysis

In the protein nutrition strategy of middle-aged and elderly people, some believe that low protein is good for health, while others believe high protein is good for health. Facing the contradictory situation, the following hypothesis is proposed. There is a process of change from lower to higher ratio of protein nutritional requirements that are good for health in the human body after about 50 years of age, and the age at which the switch occurs is around 65 years of age. Hence, in this study, 50, 25-month-old male rats were randomly divided into five groups: Control (basal diet), LP (low-protein diet with a 30% decrease in protein content compared to the basal diet), HP (high-protein diet with a 30% increase in protein content compared to the basal diet), Model 1 (switched from LP to HP feed at week 4), and Model 2 (switched from LP to HP feed at week 7). After a total of 10 weeks intervention, the liver and serum samples were examined for aging-related indicators, and a newly comprehensive quantitative score was generated using principal component analysis (PCA). The effects of the five protein nutritional modalities were quantified in descending order: Model 1 > HP > LP > Control > Model 2. Furthermore, the differential metabolites in serum and feces were determined by orthogonal partial least squares discriminant analysis, and 15 differential metabolites, significantly associated with protein intake, were identified by Spearman’s correlation analysis (p < 0.05). Among the fecal metabolites, 10 were positively correlated and 3 were negatively correlated. In the serum, tyrosine and lactate levels were positively correlated, and acetate levels were negatively correlated. MetaboAnalyst analysis identified that the metabolic pathways influenced by protein intake were mainly related to amino acid and carbohydrate metabolism. The results of metabolomic analysis elucidate the mechanisms underlying the preceding effects to some degree. These efforts not only contribute to a unified protein nutrition strategy but also positively impact the building of a wiser approach to protein nutrition, thereby helping middle-aged and older populations achieve healthy aging.

Anti-Senescence Therapy

The development of therapeutic strategies aimed at the aging process of cells has attracted increasing attention in recent decades due to the involvement of this process in the development of many chronic and age-related diseases. Interestingly, preclinical studies have shown the success of a number of anti-aging approaches in the treatment of a range of chronic diseases. These approaches are directed against aging processes such as oxidative stress, telomerase shortening, inflammation, and deficient autophagy. Many strategies has been shown to be effective in delaying aging, including antiaging strategies based on establishing healthy lifestyle habits and pharmacological interventions aimed at disrupting senescent cells and senescent-associated secretory phenotype. Caloric restriction and intermittent fasting were reported to activate autophagy and reduce inflammation. In turn, immune-based strategies, senolytic agents, and senomorphics mediate their effects either by eliminating senescent cells through inducing apoptosis or by disrupting pathways by which senescent cells mediate their detrimental effects. In addition, given the association of the decline in the regenerative potential of stem cells with aging, many experimental and clinical studies indicate the effectiveness of stem cell transplantation in preventing or slowing the progress of age-related diseases by enhancing the repairing mechanisms and the secretion of many growth factors and cytokines.

Healthy Aging: Strategies to Slow the Process

Aging, an ever-present process, is a part of every living organism's life cycle. Gerontology, the study of the biological, social, psychological aspects of aging, is a field that has been around since the 1930s, when the human inquiry into aging began to emerge. Aging can be characterized by the external changes, wrinkles, graying of the hair, among other changes, and lesser-seen but still important changes, presbycusis, arteriosclerosis, osteoporosis, cognitive decline, sarcopenia, and more. There is a strong drive to uncover as much as we can about the process of aging and the ways to delay its progression.

Effect of a 3-Week Multidisciplinary Body Weight Reduction Program on the Epigenetic Age Acceleration in Obese Adults

Obesity and aging share common molecular and cellular mechanisms underlying the pathophysiology of cardiovascular diseases (CVD), which occur frequently in both conditions. DNA methylation (DNAm) age, a biomarker of the epigenetic clock, has been proposed as a more accurate predictor of biological aging than chronological age. A positive difference between an individual’s chronological age and DNAm age is referred to as epigenetic age acceleration. The objective of the present study was to evaluate the effects of a 3-week in-hospital body weight reduction program (BWRP) on the epigenetic age acceleration, as well as on other cardiometabolic outcomes, in a cohort of 72 obese adults (F/M: 43/29; (chronological) age: 51.5 ± 14.5 yrs; BMI: 46.5 ± 6.3 kg/m2). At the end of the BWRP, when considering the entire population, BMI decreased, and changes in body composition were observed. The BWRP also produced beneficial metabolic effects as demonstrated by decreases in glucose, insulin, HOMA-IR, total cholesterol, and LDL cholesterol. A post-BWRP improvement in cardiovascular function was also evident (i.e., decreases in systolic and diastolic blood pressures and heart rate). The BWRP reduced some markers of systemic inflammation, particularly C-reactive protein (CRP). Finally, vascular age (VA) and Framingham risk score (FRS) were reduced after the BWRP. When considering the entire population, DNAm age and epigenetic age acceleration did not differ after the BWRP. However, when subdividing the population into two groups based on each subject’s epigenetic age acceleration (i.e., ≤0 yrs or >0 yrs), the BWRP reduced the epigenetic age acceleration only in obese subjects with a value > 0 yrs (thus biologically older than expected). Among all the single demographic, lifestyle, biochemical, and clinical characteristics investigated, only some markers of systemic inflammation, such as CRP, were associated with the epigenetic age acceleration. Moreover, chronological age was correlated with DNAm age and VA; finally, there was a correlation between DNAm age and VA. In conclusion, a 3-week BWRP is capable of reducing the epigenetic age acceleration in obese adults, being the BWRP-induced rejuvenation evident in subjects with an epigenetic age acceleration > 0 yrs. Based on the BWRP-induced decrease in CRP levels, chronic systemic inflammation seems to play a role in mediating obesity-related epigenetic remodeling and biological aging. Thus, due to the strong association of CVD risk with the epigenetic clock and morbidity/mortality, any effort should be made to reduce the low-grade chronic inflammatory state in obesity.

Calorie Restriction-Regulated Molecular Pathways and Its Impact on Various Age Groups: An Overview

Calorie restriction (CR) if planned properly with regular exercise at different ages can result in healthy weight loss. CR can also have different beneficial effects on improving lifespan and decreasing the age-associated diseases by regulating physiological, biochemical, and molecular markers. The different pathways regulated by CR include:(1) AMP-activated protein kinase (AMPK), which involves PGC-1α, SIRT1, and SIRT3. AMPK also effects myocyte enhancer factor 2 (MEF2), peroxisome proliferator-activated receptor delta, and peroxisome proliferator-activated receptor alpha, which are involved in mitochondrial biogenesis and lipid oxidation; (2) Forkhead box transcription factor's signaling is related to the DNA repair, lipid metabolism, protection of protein structure, autophagy, and resistance to oxidative stress; (3) Mammalian target of rapamycin (mTOR) signaling, which involves key factors, such as S6 protein kinase-1 (S6K1), mTOR complex-1 (mTORC1), and 4E-binding protein (4E-BP). Under CR conditions, AMPK activation and mTOR inhibition helps in the activation of Ulk1 complex along with the acetyltransferase Mec-17, which is necessary for autophagy; (4) Insulin-like growth factor-1 (IGF-1) pathway downregulation protects against cancer and slows the aging process; (5) Nuclear factor kappa B pathway downregulation decreases the inflammation; and (6) c-Jun N-terminal kinase and p38 kinase regulation as a response to the stress. The acute and chronic CR both shows antidepression and anxiolytic action by effecting ghrelin/GHS-R1a signaling. CR also regulates GSK3β kinase and protects against age-related brain atrophy. CR at young age may show many deleterious effects by effecting different mechanisms. Parental CR before or during conception will also affect the health and development of the offspring by causing many epigenetic modifications that show transgenerational transmission. Maternal CR is associated with intrauterine growth retardation effecting the offspring in their adulthood by developing different metabolic syndromes. The epigenetic changes with response to paternal food supply also linked to offspring health. CR at middle and old age provides a significant preventive impact against the development of age-associated diseases.

The Aged Intestine: Performance and Rejuvenation

Owing to the growing elderly population, age-related problems are gaining increasing attention from the scientific community. With senescence, the intestine undergoes a spectrum of changes and infirmities that are likely the causes of overall aging. Therefore, identification of the aged intestine and the search for novel strategies to rescue it, are required. Although progress has been made in research on some components of the aged intestine, such as intestinal stem cells, the comprehensive understanding of intestinal aging is still limited, and this restricts the in-depth search for efficient strategies. In this concise review, we discuss several aspects of intestinal aging. More emphasis is placed on the appraisal of current and potential strategies to alleviate intestinal aging, as well as future targets to rejuvenate the aged intestine.

Diet and Skin Aging-From the Perspective of Food Nutrition

We regularly face primary challenges in deciding what to eat to maintain young and healthy skin, defining a healthy diet and the role of diet in aging. The topic that currently attracts maximum attention is ways to maintain healthy skin and delay skin aging. Skin is the primary barrier that protects the body from external aggressions. Skin aging is a complex biological process, categorized as chronological aging and photo-aging, and is affected by internal factors and external factors. With the rapid breakthrough of medicine in prolonging human life and the rapid deterioration of environmental conditions, it has become urgent to find safe and effective methods to treat skin aging. For diet, as the main way for the body to obtain energy and nutrients, people have gradually realized its importance to the skin. Therefore, in this review, we discuss the skin structure, aging manifestations, and possible mechanisms, summarize the research progress, challenges, possible directions of diet management, and effects of foodborne antioxidants on skin aging from the perspective of food and nutrition.

Global and local diet popularity rankings, their secular trends, and seasonal variation in Google Trends data

OBJECTIVES

The Internet has become the main source of health-related information including nutrition. The aim of this study was to rank the most popular diets among Google users globally and regionally in addition to secular and seasonal trends in the years 2004 to 2019.

METHODS

We used Google Trends (GT) to identify and analyze course over time and regional interest of 47 topics related to diets. We analyzed secular trends using the Seasonal Mann-Kendall test and seasonal variation using time-series decomposition. The topic "Mediterranean diet" (MedD) was used as a benchmark. We calculated the interest of all topics in proportion to the relative search volume (RSV) of MedD.

RESULTS

Globally, Google users were particularly interested in veganism (19.54 times higher than MedD), vegetarianism (15.09 times higher than MedD), and gluten-free diet (11.11 times higher than MedD). Veganism was the most frequently searched diet type in 23 countries followed by vegetarianism (14), ketogenic diet (7), and low-carbohydrate diet (7). Whereas an increase of RSV over time was observed for 23 diets, a decrease was noted for 20. The most dynamic increase was found for FODMAP (6.12 RSV/year), gluten-free diet (5.95 RSV/year), and raw veganism (5.72 RSV/year). Sharp declines concerned negative-calorie food (-4.34 RSV/year), macrobiotic diet (-3.89 RSV/year), and cabbage soup diet (-3.50 RSV/year). The interest in most diets falls in December but peaks in January.

CONCLUSION

Veganism, vegetarianism, and gluten-free diet attract the largest public interest globally. Both secular trends and seasonal variation shape the ever-changing landscape of diet popularity. GT holds promise as a valuable tool in local and international nutrition research.

Respiratory

Lung disease rivals the position for the top cause of death worldwide. Causes and pathology of the myriad lung diseases are varied, yet nutrition can either affect the outcome or support treatment in the majority of cases. This chapter explores the modifiable risk factors, from lifestyle changes to dietary intake to specific nutrients, anti-nutrients, and toxins helpful for the nutritionist or dietitian working with lung disease patients. General lung health is discussed, and three major disease states are explored in detail, including alpha-1 antitrypsin deficiency, asthma, and idiopathic pulmonary fibrosis. Although all lung diseases have diverse causes, many integrative and functional medical nutrition therapies are available and are not being utilized in practice today. This chapter begins the path toward better nutrition education for the integrative and functional medicine professional.

Resetting the Aging Clock: Implications for Managing Age-Related Diseases

Worldwide, individuals are living longer due to medical and scientific advances, increased availability of medical care and changes in public health policies. Consequently, increasing attention has been focused on managing chronic conditions and age-related diseases to ensure healthy aging. The endogenous circadian system regulates molecular, physiological and behavioral rhythms orchestrating functional coordination and processes across tissues and organs. Circadian disruption or desynchronization of circadian oscillators increases disease risk and appears to accelerate aging. Reciprocally, aging weakens circadian function aggravating age-related diseases and pathologies. In this review, we summarize the molecular composition and structural organization of the circadian system in mammals and humans, and evaluate the technological and societal factors contributing to the increasing incidence of circadian disorders. Furthermore, we discuss the adverse effects of circadian dysfunction on aging and longevity and the bidirectional interactions through which aging affects circadian function using examples from mammalian research models and humans. Additionally, we review promising methods for managing healthy aging through behavioral and pharmacological reinforcement of the circadian system. Understanding age-related changes in the circadian clock and minimizing circadian dysfunction may be crucial components to promote healthy aging.

Current and Future Nutritional Strategies to Modulate Inflammatory Dynamics in Metabolic Disorders

Obesity, type 2 diabetes, and other metabolic disorders have a large impact on global health, especially in Western countries. An important hallmark of metabolic disorders is chronic low-grade inflammation. A key player in chronic low-grade inflammation is dysmetabolism, which is defined as the inability to keep homeostasis resulting in loss of lipid control, oxidative stress, inflammation, and insulin resistance. Although often not yet detectable in the circulation, chronic low-grade inflammation can be present in one or multiple organs. The response to a metabolic challenge containing lipids may magnify dysfunctionalities at the tissue level, causing an overflow of inflammatory markers into the circulation and hence allow detection of early low-grade inflammation. Here, we summarize the evidence of successful application of metabolic challenge tests in type 2 diabetes, metabolic syndrome, obesity, and unhealthy aging. We also review how metabolic challenge tests have been successfully applied to evaluate nutritional intervention effects, including an "anti-inflammatory" mixture, dark chocolate, whole grain wheat and overfeeding. Additionally, we elaborate on future strategies to (re)gain inflammatory flexibility. Through epigenetic and metabolic regulation, the inflammatory response may be trained by regular mild and metabolic triggers, which can be understood from the perspective of trained immunity, hormesis and pro-resolution. New strategies to optimize dynamics of inflammation may become available.

Recurrent circadian fasting (RCF) improves blood pressure, biomarkers of cardiometabolic risk and regulates inflammation in men

Background

The effects of fasting on health in non-human models have been widely publicised for a long time and emerging evidence support the idea that these effects can be applicable to human practice.

Methods

In an open label longitudinal follow-up, a cohort of 78 adult men (aged 20 to 85 years) who fasted for 29 consecutive days from sunrise to sunset (16 h fasting—referred to as recurrent circadian fasting) in Pakistan, were studied. The primary outcomes of the fasting study was weight loss/recovery and the associated changes in blood pressure and circulating levels of surrogate markers linked to organ and system functions—including cardiovascular, metabolic and inflammation. Post-fasting outcomes include the regulation of physiological biomarkers.

Results

Recurrent circadian fasting with weight loss reduced blood pressure (140.6 vs. 124.2 mmHg) and markers of cardiovascular risk (~ 4-fold for resistin; triglycerides: p < 0.0001). Reduced glycemia (p < 0.0001) and the associated changes in the regulation of ketosis (β-hydroxybutyrate) were accompanied by a metabolic shift (PPARβ, osteoprotegerin), suggesting the involvement of the different physiological systems tested. Elevated orexin-A levels (p = 0.0183) in participants indicate sleep disturbance and circadian adaptation. All participants had CRP level < 2 mg/l during the fasting period and a similar trend was observed for TNFα. While most SASP molecules were decreased after the fasting period, heightened levels of IL-8 and IL-6 suggest that some inflammatory markers may be elevated by recurrent circadian fasting. Importantly, older adults reveal similar or more substantial benefits from fasting.

Conclusions

Recurrent circadian fasting is beneficial at the cardiometabolic and inflammatory levels, especially for at-risk individuals—this is contingent on compliance towards the recommended dietary behaviour, which controls carbohydrate and caloric intake. These benefits from fasting may be particularly beneficial to older adults as they often exhibit abnormal cardiovascular, metabolic and inflammatory signatures.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-2007-z) contains supplementary material, which is available to authorized users.

Slowing Down Ageing: The Role of Nutrients and Microbiota in Modulation of the Epigenome

The human population is getting ageing. Both ageing and age-related diseases are correlated with an increased number of senescent cells in the organism. Senescent cells do not divide but are metabolically active and influence their environment by secreting many proteins due to a phenomenon known as senescence associated secretory phenotype (SASP). Senescent cells differ from young cells by several features. They possess more damaged DNA, more impaired mitochondria and an increased level of free radicals that cause the oxidation of macromolecules. However, not only biochemical and structural changes are related to senescence. Senescent cells have an altered chromatin structure, and in consequence, altered gene expression. With age, the level of heterochromatin decreases, and less condensed chromatin is more prone to DNA damage. On the one hand, some gene promoters are easily available for the transcriptional machinery; on the other hand, some genes are more protected (locally increased level of heterochromatin). The structure of chromatin is precisely regulated by the epigenetic modification of DNA and posttranslational modification of histones. The methylation of DNA inhibits transcription, histone methylation mostly leads to a more condensed chromatin structure (with some exceptions) and acetylation plays an opposing role. The modification of both DNA and histones is regulated by factors present in the diet. This means that compounds contained in daily food can alter gene expression and protect cells from senescence, and therefore protect the organism from ageing. An opinion prevailed for some time that compounds from the diet do not act through direct regulation of the processes in the organism but through modification of the physiology of the microbiome. In this review we try to explain the role of some food compounds, which by acting on the epigenetic level might protect the organism from age-related diseases and slow down ageing. We also try to shed some light on the role of microbiome in this process.

The Role of Curcumin in the Modulation of Ageing

It is believed that postponing ageing is more effective and less expensive than the treatment of particular age-related diseases. Compounds which could delay symptoms of ageing, especially natural products present in a daily diet, are intensively studied. One of them is curcumin. It causes the elongation of the lifespan of model organisms, alleviates ageing symptoms and postpones the progression of age-related diseases in which cellular senescence is directly involved. It has been demonstrated that the elimination of senescent cells significantly improves the quality of life of mice. There is a continuous search for compounds, named senolytic drugs, that selectively eliminate senescent cells from organisms. In this paper, we endeavor to review the current knowledge about the anti-ageing role of curcumin and discuss its senolytic potential.

Emerging Anti-Aging Strategies - Scientific Basis and Efficacy

The prevalence of age-related diseases is in an upward trend due to increased life expectancy in humans. Age-related conditions are among the leading causes of morbidity and death worldwide currently. Therefore, there is an urgent need to find apt interventions that slow down aging and reduce or postpone the incidence of debilitating age-related diseases. This review discusses the efficacy of emerging anti-aging approaches for maintaining better health in old age. There are many anti-aging strategies in development, which include procedures such as augmentation of autophagy, elimination of senescent cells, transfusion of plasma from young blood, intermittent fasting, enhancement of adult neurogenesis, physical exercise, antioxidant intake, and stem cell therapy. Multiple pre-clinical studies suggest that administration of autophagy enhancers, senolytic drugs, plasma from young blood, drugs that enhance neurogenesis and BDNF are promising approaches to sustain normal health during aging and also to postpone age-related neurodegenerative diseases such as Alzheimer's disease. Stem cell therapy has also shown promise for improving regeneration and function of the aged or Alzheimer's disease brain. Several of these approaches are awaiting critical appraisal in clinical trials to determine their long-term efficacy and possible adverse effects. On the other hand, procedures such as intermittent fasting, physical exercise, intake of antioxidants such as resveratrol and curcumin have shown considerable promise for improving function in aging, some of which are ready for large-scale clinical trials, as they are non-invasive, and seem to have minimal side effects. In summary, several approaches are at the forefront of becoming mainstream therapies for combating aging and postponing age-related diseases in the coming years.