TITLE: Special: Dietary Interventions for Healthspan

SUBTITLE:  Biogerontology. Volume 23, Issue 6 

INTRODUCTION:This is a remarkable issue of long reviews of how diet can increase healthspan.  It contains vast scientific evidence about specific dietary action with rapid benefits.

SHORT NOTES: There is a general consensus that nutrition plays a key role in determining the health status and duration of life of an individual.  The most holistic and innovative approach is caloric/dietary restriction and Chrononutrition. Ageing is accompanied by alterations in several biochemical processes, highly influenced by its environment. To maintain homeostasis, a number of nutrient sensors respond to the nutritional status of the cell and control its energy metabolism. Mitochondrial physiology is influenced by the energy status of the cell.

The induction of dietary protocols such as caloric restriction (CR) and protein restriction (PR) has positively affected a healthy lifespan. These intervention ideas have been the subject of human cohort studies and clinical trials to evaluate their effectiveness in alleviating age-related diseases (such as type II diabetes, cardiovascular disease, obesity, and musculoskeletal fragility) and promoting human longevity. This study summarizes the literature on the nutritional protocols, emphasizing their impacts on bone and muscle biology.  Immunological aging is strongly associated with the observable deleterious effects of human aging. We discuss the emerging significance of dietary factors such as phytochemicals, probiotic bacteria, fatty acids, and micronutrients as possible modulators of immunosenescence and cellular senescence- probiotics, milk fermented with probiotic, oral application of vitamins C D, K, B, and E to elderly subjects improved blood neutrophils and lymphocytes functions, zinc reduces chronic inflammation, immunosenescence, and increased susceptibility to infections, copper and iron . IMPORTANT DIETARY FACTORS: EGCG, Resveratrol, lignan, carotenoids, polyphenols, yogurt or kefir, EPA & DHA, vitamins C, D, E, K, B6, Zn and Cu (note AREDsII provides suffient C, E, Zn, and Cu).  The Mediterranean diet or plant-based diets, have shown the potential to suppress inflamm-aging as well as cellular senescence. As the kidneys age, gradual changes in the structures and functions of mitochondria occur. Dietary restriction (DR) can play a protective role in ageing-associated renal decline.

LONG NOTES:

We are pleased to deliver your requested table of contents alert for Biogerontology. Volume 23, Issue 6 is now available online.
S. I: Dietary Interventions for Healthy Ageing and Longevity

Editorial note for special issue

There is a general consensus that nutrition plays a key role in determining the health status and duration of life of an individual.  the most holistic and innovative approach, which is also relatively easy to compliant and sustain, is caloric/dietary restriction and Chrononutrition.  Various nutrient sensors such as mTOR, AMPK and sirtuins are involved in the modulation of mitochondrial functions like their biogenesis, oxidative phosphorylation, autophagy as well as turnover. The timely and appropriate dietary interventions may alleviate the ill effects of ageing associated with these two hallmarks. Another review article by Murphy et al. (2022) summarizes the literature reports on the role of various dietary/nutritional interventions in relevance to their impact on bone and muscle health. The third review article by Sharma et al. (2022) is an overview of the impact of cellular senescence in immune cells

Mitochondrial function and nutrient sensing pathways in ageing: enhancing longevity through dietary interventions

Ageing is accompanied by alterations in several biochemical processes, highly influenced by its environment. To maintain homeostasis, a number of nutrient sensors respond to the nutritional status of the cell and control its energy metabolism. Mitochondrial physiology is influenced by the energy status of the cell. Calorie restriction (CR) has proved to be as the most successful intervention to achieve the goal of longevity and healthspan.

Dietary interventions and molecular mechanisms for healthy musculoskeletal aging

The induction of dietary protocols such as caloric restriction (CR) and protein restriction (PR) has positively affected a healthy lifespan. These intervention ideas (nutritional protocols) have been the subject of human cohort studies and clinical trials to evaluate their effectiveness in alleviating age-related diseases (such as type II diabetes, cardiovascular disease, obesity, and musculoskeletal fragility) and promoting human longevity. This study summarizes the literature on the nutritional protocols, emphasizing their impacts on bone and muscle biology. We identified nine novel common genes, out of which five were upregulated (Emc3, Fam134b, Fbxo30, Pip5k1a, and Retsat), and four were downregulated (Gstm2, Per2, Fam78a, and Sel1l3) with CR in muscles.

Emerging cellular senescence-centric understanding of immunological aging and its potential modulation through dietary bioactive components

Immunological aging is strongly associated with the observable deleterious effects of human aging. Our understanding of the causes, effects, and therapeutics of aging immune cells has long been considered within the sole purview of immunosenescence. However, it is being progressively realized that immunosenescence may not be the only determinant of immunological aging. we discuss the emerging significance of dietary factors such as phytochemicals, probiotic bacteria, fatty acids, and micronutrients as possible modulators of immunosenescence and cellular senescence. Evidence and opportunities related to nutritional bioactive components and immunological aging have been deliberated to augment potential nutrition-oriented immunotherapy during aging. The composition of the gut microbiota strongly influences the type of immune response. application of probiotics is considered useful for the maintenance of gut eubiosis and improved immunological response and homeostasis. Application of a probiotic cocktail containing 5 Lactobacillus and 5 Enterococcus strains to old mice prevented the leaky gut by improving the expression of tight junction proteins that ultimately prevented unwarranted aggravation of intestinal immune cells and thus inflammation (Ahmadi et al. 2020). Supplementation of milk fermented with probiotic microbes improved the redox state and functions of peritoneal immune cells such as macrophages and NK cell in aged mice (Hunsche et al. 2019). Administration of Lactobacillus acidophilus DDS-1 to aging mice attenuated the proinflammatory profile in serum and colonic explants as compared to age match controls (Vemuri et al. 2019). Polyunsaturated fatty acids (PUFAs), especially n-3 PUFA such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are important constituents of a healthy diet and are implicated in a myriad of health beneficial effects including against cardiovascular diseases, chronic inflammation, diabetes, and age-related cognitive decline (Shahidi and Ambigaipalan 2018).

Micronutrients such as vitamins and minerals are essential for immunocompetence and their nutritional deficiency is associated with inadequate immunological response (Alpert 2017; Djukic et al. 2014). Micronutrients can influence multiple aspects of immune functions such as activation of phagocytes, regulation of inflammation, antigen presentation, as well as humoral antibody response (Gombart et al. 2020). Studies have also shown that supplementation with certain vitamins and minerals can counter immunosenescence and boost the immune response in elderly. For instance, oral application of vitamins C and E to elderly subjects improved blood neutrophils and lymphocytes functions which were maintained even after 6 months of treatment (De la Fuente et al. 2020). Clinical trials of vitamin D have observed improved response to vaccines and enhanced ability to resist respiratory infections in old age adults (Ginde et al. 2017; Goncalves-Mendes et al. 2019; Sadarangani et al. 2016). the role of zinc is recognized as of particular significance in countering immunological aging (Baarz and Rink 2022). That elderly are often deficient in zinc suggesting a direct correlation between chronic inflammation, immunosenescence, and increased susceptibility to infections (Cabrera 2015). Studies have demonstrated that dietary supplementation with zinc can reverse several facets of immunosenescence as evident by increased naïve T-cell subset (Wong et al. 2020, 2021), improved immune cell functions (Barnett et al. 2016; Varin et al. 2008), increased thymopoiesis (Wong et al. 2009), attenuated inflamm-aging (Wong et al. 2013), and modulated Th1/Th2 immune homeostasis (Uciechowski et al. 2008) during aging. In addition to zinc, copper (Giacconi et al. 2017; Malavolta et al. 2015) and iron (Handono et al. 2021; Macciò and Madeddu 2012) deficiency is also correlated with aging and health, including immunosenescence. It is important to consider that although elderly often have dietary deficiency of minerals such as zinc, copper, selenium, and iodine (Vural et al. 2020) as well as vitamins including vitamins D, K, and B (Fabian et al. 2012; Wei et al. 2019); indiscriminate supplementation of vitamins and minerals in individuals with no clinical deficiency is considered controversial.

S. no. Dietary factors Reported effects Experimental model References
1 EGCG Anti-SASP and anti-cellular senescence effects ex vivo Murine macrophages Kumar et al. (2020b)
2 Resveratrol Suppression of inflamm-aging and oxidative stress in immune cells in vivo Sprague-Dawley rats Garrigue et al. (2021)
3 Lignan Anti-immunosenescence effects in vivo ICR mice Li et al. (2020)
4 Carotenoids Improved immunoglobulins profile during aging in vivo Rats Chen et al. (2020)
5 Polysaccharide preparations Improved humoral immune response against influenza vaccine during aging Clinical trial Laue et al. (2021)
6 Polyphenol-rich diet Anti-inflammaging effects and gut eubiosis during aging Clinical trial Del Bo et al. (2021)
7 Lactobacillus casei CRL 431 Anti-immunosenescence effects including on thymus Aged mice Balcells et al. (2022)
8 Probiotic Akkermansia muciniphila Modulation of colonic B cell migration and inflammation Aging Ercc1-/Δ7 mice van der Lugt et al. (2019)
9 Synbiotic preparation Increased proliferation and activation of CD3+ T cells Aged mice Sharma et al. (2019)
10 n-3 PUFAs Increased telomere length of blood leucocytes Clinical trial Ali et al. (2022)
11 EPA and DHA Anti-inflamm-aging Clinical trial Tan et al. (2018)
12 Vitamins C&E Improved neutrophils and lymphocyte functional markers Clinical trial De la Fuente et al. (2020)
13 Zinc Increased naïve T-cell subset Aged mice Wong et al. (2020)

Functional foods and especially curated diets, such as the Mediterranean diet or plant-based diets, have shown the potential to suppress inflamm-aging as well as cellular senescence (Canudas et al. 2020; Crous-Bou et al. 2019; García-Calzón et al. 2015; Sharma and Diwan 2022).

Long-term dietary restriction ameliorates ageing-related renal fibrosis in male mice by normalizing mitochondrial functions and autophagy

As the kidneys age, gradual changes in the structures and functions of mitochondria occur. Dietary restriction (DR) can play a protective role in ageing-associated renal decline, however the exact mechanisms involved are still unclear. To conclude, impaired mitochondria, increased oxidative stress, and severe fibrosis were noticed in the aged kidneys, and DR improved these changes by increasing functional mitochondria and promoting autophagic clearance