June 24, 2024

Reflections and Advice from 50 Years as an Anti-Aging Expert

Introduction

Growing up under the influence of the Philadelphia version of Archie Bunker molded me into someone who instinctively questions and challenges conventional wisdom, extending this unique perspective into every facet of my life, even my chosen profession. Much like the curmudgeonly and unapologetically conservative patriarch on the iconic TV series “All in the Family,” this upbringing has infused me with a penchant for contrarian viewpoints, ensuring that I approach every situation with a critical eye and an independent mind.

My professional focus over the past four decades revolved around unraveling and challenging the often misguided “standards of care” entrenched within the medical establishment.

Beginning in the formative years of the 1970s with the advent of the groundbreaking “Pritikin Program and evolving into the sophisticated integrative methodologies we implement today, this journey has featured pivotal scientific revelations, transformative paradigm shifts, staunch critics, and an unwavering pursuit of enhanced well-being and quality of life.

The 70s: Follow Your Passions

Dr. James Naccarato, Utah psychologist extraordinaire, defines a “White Hot Imperative (WHI)” as a directive or motivation characterized by extreme urgency and intensity. The WHI signifies a psychological or emotional command that compellingly drives behavior. The individual has no choice but to carry out the directive to make their life meaningful.  A “white-hot imperative” is that thing to make a difference in how medical care is perceived and delivered, which has driven me every step of the way. (2)

My “white hot imperative” was ignited at the College of Osteopathic Medicine and Surgery (COMS, now Des Moines University) in Des Moines, Iowa, mid to late 1970s. Choosing a holistic alternative to traditional MD schools, I was drawn to osteopathic medicine’s comprehensive approach to patient care, emphasizing the interrelationship between structure and function and the body’s innate ability to heal itself. This foundational philosophy resonated deeply with me, setting the stage for a career integrating conventional and alternative therapies.

What follows is a “best of” holistic or anti-aging tips resulting from my white-hot imperative, bringing the latest, most up-to-date, little-known at the time, practical, “ alternative and anti-aging therapies.”

The 1970s: My Medical Student Journey at the College of Osteopathic Medicine and Surgery, Des Moines, Iowa

I hit the ground running as I learned the basics from a colorful array of Midwest characters:

      1. Acupuncture: (3) In 1972, while Traveling with President Richard Nixon during his historic trip to China, James Reston, a reporter with the New York Times, experienced an appendicitis attack. He described the use of acupuncture as an anesthetic, as he was fully awake during his surgery. I studied medical acupuncture at the UCLA School of Medicine in 1990-91 and became Pennsylvania’s 5th fully licensed physician acupuncturist in 1995. 

        1. Telomeres and Telomerase: Telomeres are protective caps at the ends of chromosomes, maintained by the enzyme telomerase, which can reverse their shortening associated with aging. Supporting telomere health is crucial for longevity. Key nutrients for telomere health include cysteine, zinc, magnesium, copper, manganese, selenium, B vitamins, vitamin C, and vitamin E. Managing stress, which can shorten telomeres, is essential, with helpful nutrients including serine, α-lipoic acid, and several B vitamins. A holistic lifestyle approach further supports telomere health. This involves an anti-inflammatory diet, 150 minutes of aerobic exercise weekly, effective stress management, and strong social support. The enzyme telomerase can restore telomere length, making it a significant factor in promoting overall well-being and longevity.

          1. The Pritikin Clinic: (10) In 1976, Nathan Pritikin founded the Pritikin Longevity Center, emphasizing a diet low in fat and unprocessed carbohydrates and regular exercise. The program demonstrated significant results, including weight loss, reduced cholesterol levels, and improved cardiovascular health, which contribute to a longer and healthier life. Participants could reverse conditions like hypertension and diabetes through lifestyle changes. In 1977, I spent four weeks at the clinic’s in-house and outpatient center in Santa Monica, California, learning the benefits of a noninflammatory diet and exercise in rehabilitating cardiac patients. In 1986, I earned a degree in cardiac rehabilitation from the University of Wisconsin-Lacrosse.

          1. Caloric Restriction: Reducing calorie intake without malnutrition extends the lifespan of various organisms. It delays the onset of age-related diseases and improves overall health by reducing metabolic rate and oxidative damage. Benefits of calorie restriction include weight loss, improved cardiovascular health, enhanced cognitive function, longevity, muscle strength, and activation of beneficial telomerase activity.

          1. Antioxidant Theory of Aging: Free radicals, unstable molecules with unpaired electrons, cause significant damage to cells, proteins, DNA, and other essential molecules in the body through oxidation. Antioxidants like Vitamin C, Vitamin E, and Beta-carotene reduce oxidative stress by stabilizing reactive molecules without becoming free radicals themselves.

        The 1980s: Residency and Private Practice, Wilkes Barre, PA

        As I started my residency and private practice, I discovered several groundbreaking advancements that significantly influenced my approach to medicine and aging.

        The SIR2 Gene

        The discovery of the SIR2 gene in yeast marked a significant breakthrough in understanding aging. This gene encodes a protein that regulates the compactness of DNA packaging within cells, influencing gene activation and deactivation. This process is crucial for maintaining genetic stability and impacting aging. Increased activity of the SIR2 gene in yeast was found to extend its lifespan (14).

        In humans and other animals, similar genes called sirtuins (such as SIRT1 and SIRT2) play roles in DNA repair, metabolism, inflammation control, and cell survival. Sirtuins require NAD+ to function, linking their activity to the cell’s energy levels. Trans-resveratrol from Longevinex activates sirtuins, potentially extending lifespan and improving health as we age.

        Hormone Replacement Therapy (HRT)

        Advances in hormone replacement therapy (HRT) during the 1980s brought new insights into managing menopausal symptoms and understanding the hormonal impact on cognition, psychiatric well-being, and aging. Although HRT became my specialty two decades later, I learned in the ‘80s that HRT alleviated symptoms like hot flashes, night sweats, brain fog, memory loss, agitation, irritability, insomnia, headaches, mood swings, vaginal dryness, osteoporosis, and a short temper (15).

        Extensive studies, such as the Women’s Health Initiative (WHI) and the E3N EPIC Study, found that long-term use of synthetic hormones increased the risk of breast cancer, stroke, and blood clots. In contrast, natural hormones tended to have no change or even a decreased risk of cancers compared to no hormone therapy at all (16).

        Low Dose Naltrexone

        In 1985, New York City physician Bernard Bihari discovered that AIDS patients had significantly lower endorphin levels than those with normal immune systems, which weakened their immune defenses (17). Dr. Bihari reasoned that raising endorphin levels would strengthen a patient’s natural defenses (18).

        In 1984, the FDA approved naltrexone, an opioid receptor antagonist, to treat alcohol and opioid dependence. At the standard prescription dose of 50-100 mg per day, naltrexone blocks the euphoric effect of alcohol and opioids, decreasing endorphin production and stimulating tumor cell growth. Dr. Bihari reduced the naltrexone concentration by 90% to 5 mg per day, creating low-dose naltrexone (LDN). At this dose, LDN increases endorphin production, enhances immune cell production, and mitigates inflammation (19).

        LDN’s mechanism of action includes increasing endorphin activity and receptors, reducing pro-inflammatory cytokines, increasing anti-inflammatory cytokines, and regulating the Opioid Growth Factor/Opioid Growth Factor receptor (OGF/OGFr) axis (20). Below is a summary of conditions studied by the LDN community (21).

        Exercise, Aging, and Longevity

            1. Cardiovascular health: Regular aerobic exercise improves cardiovascular health, reducing the risk of heart disease and stroke. Men who engaged in regular moderate-intensity exercise – 300 to 600 minutes per week – had a 26%-31% lower risk of death from any cause compared with almost no long-term moderate-intensity exercise. (22)

            2. Muscle strength and function: A landmark 1980 study revealed the benefits of high-intensity resistance training resulting in significantly increased muscle strength and size in frail elderly individuals, even those in their 90s. (23)

            3. Bone health: Weight-bearing exercises maintain bone mineral density and reduce osteoporosis risk. (24)

            4. Cognitive function: Older adults who are physically active have better reaction times and psychomotor speed than their sedentary counterparts. Exercise has a protective effect on brain function. (25)

            5. Longevity: Regular physical activity was associated with increased life expectancy. One hundred fifty minutes of exercise or more each week increased life expectancy by about 7 years over those who didn’t do regular moderate exercise. (26) All-cause mortality is decreased by about 30% to 35% in the physically active adults. (27)

            6. Growth Hormone, IGF-1 and, Anti Aging: Human Growth Hormone (HGH), produced by the pituitary gland, is crucial for growth and metabolism. Insulin Growth Factor (IGF), the active form of HGH produced in the liver, mediates HGH’s effects. HGH levels decline with age, but HGH optimization in older adults can reverse these age-related changes, leading to increased lean body mass, decreased adipose tissue, and improved bone density. IGF-1 promotes cellular growth and repair, enhancing muscle regeneration and cognitive function (28). However, safety concerns link HGH to increased risks of cancer, cardiovascular diseases, and insulin resistance. The misuse of HGH in sports, such as athletes hitting unprecedented home runs late in their careers, raises ethical and health concerns (29).

          The 1990s: The Medical Maverick I Join a 52-Doctor Group

          Dolly, the First Cloned Mammal

          In 1996, scientists at the Roslin Institute in Scotland successfully cloned a sheep named Dolly using a technique called somatic cell nuclear transfer (SCNT). This experiment demonstrated the possibility of creating a genetically identical copy of an adult mammal from a single somatic (body) cell. Scientists transferred the nucleus from an adult udder cell into an enucleated egg cell, which they stimulated to develop into an embryo and implanted into a surrogate mother (30-31).

          Dolly’s birth showed that differentiated cells, which had already developed into specific types, could be reprogrammed back to an embryonic state. This finding challenged the long-standing belief that cellular differentiation was a one-way process, meaning once a cell became specialized, it could not return to its original undifferentiated state. Dolly’s successful cloning demonstrated that differentiated cells could be reprogrammed under certain conditions, potentially allowing them to develop into an entire organism. Dolly’s birth opened inquiries into aging research, as cloning technology could be used to study the genetic and epigenetic changes associated with aging.

          Dolly also sparked ethical debates about the potential applications of cloning technology. Questions arose about whether humans should be cloned and whether it is ethical to clone joints, limbs, or organs. The potential of creating cloned embryos or harvesting stem cells, which can regenerate damaged tissues and treat various degenerative diseases without the risk of immune rejection, further fueled the debate. Dolly revolutionized the understanding of developmental biology and aging, demonstrating the flexibility of differentiated cells and opening new research possibilities in regenerative and age-related medical studies.

          Resveratrol

          Resveratrol is a highly purified and potent age-defying polyphenol derived from Japanese knotweed. Most resveratrol on the market contains the cis-isomer, but the trans formulation is the one that epigenetically stimulates longevity and drives cellular respiration. Trans-resveratrol (RSV) protects cells from oxidative stress, supports cardiovascular health, reduces inflammation, resists neoplastic cell changes, and enhances memory, cognition, and bone strength (32-38).

          Studies suggest that trans-resveratrol mimics calorie restriction by activating sirtuin pathways, leading to increased lifespan and improved health. It reduces inflammation, improves HDL cholesterol, reduces LDL cholesterol, increases insulin sensitivity, and protects the heart. From a weight reduction perspective, resveratrol converts white fat to brown fat, increasing energy consumption and promoting weight stabilization and loss.

          A randomized trial administering 500 mg of resveratrol three times daily for 90 days revealed significant reductions in total weight, body mass index (BMI), fat mass, and waist circumference. Insulin levels and the insulinogenic index also decreased significantly.

          The best resveratrol formulas I’ve found on the market are Longevinex®  and Advantage®, which offer high-quality trans-resveratrol, ensuring optimal benefits for longevity and overall health.

          The 2000s: Anti-Aging Medicine Comes to Northeast Pennsylvania

          As I delved deeper into anti-aging medicine during the 2000s, several key developments significantly shaped my approach to treating age-related conditions.

          Rapamycin

          Rapamycin, an antifungal drug discovered in the soil of Easter Island in 1972, exhibits potent immunosuppressive and antiproliferative properties. It binds to and inhibits the mechanistic target of rapamycin (mTOR) pathway. The mTOR signaling pathway has four main functions: cell growth, proliferation and angiogenesis, metabolism enhancement, and decreasing autophagy (42-45). Dysregulation of autophagy is associated with neurodegenerative diseases, cancers, infectious diseases, and metabolic issues. Rapamycin inhibits cell proliferation, making it useful for tumor regulation, and mimics caloric restriction without dietary changes, making it valuable for anti-obesity and longevity.

          Most major laboratories can measure Sirolimus (the generic name for rapamycin) serum levels, which are available as a prescription drug under the brand name Rapaimmune or as generic Sirolimus. Generic rapamycin is typically dosed at 1-5 mg once weekly.

          The First GLP-1s: Calorie Restriction Mimetics

          In the early 2000s, the first glucagon-like peptide-1 (GLP-1) receptor agonists were developed to control type 2 diabetes (46-49). GLP-1 receptor agonists stimulate insulin secretion, inhibit glucagon release, slow gastric emptying, and promote satiety, making them effective for diabetes management and weight control.

          Exenatide (Byetta, Byduron): 

          Derived from the saliva of the Gila monster, exenatide lowers blood sugars by increasing insulin release, inhibiting glucagon secretion, and slowing gastric emptying. Side effects include nausea, vomiting, diarrhea, and constipation.

          Liraglutide: 

          Mimicking GLP-1, liraglutide has a prolonged half-life allowing for once-daily dosing. Approved in 2010 for treating type 2 diabetes, it effectively lowers blood sugar levels, promotes weight loss, and improves cardiovascular outcomes.

          Impact and Benefits of GLP-1s: GLP-1 receptor agonists improve glycemic control, promote weight loss, and provide cardiovascular benefits, reducing the risk of major adverse cardiovascular events. The success of exenatide and liraglutide led to the development of newer agents like semaglutide and tirzepatide, offering improved benefits and fewer side effects.

          Stem Cell Therapies

          Research advancements during the 2000s explored the use of stem cells and their platelet-rich plasma derivatives to regenerate aged or damaged tissues (50-52). Injecting stem cells from young mice into old mice suggested that stem cell therapies could combat age-related decline and rejuvenate tissues. Stem cells from younger organisms have higher telomerase activity, enabling them to replace or repair damaged cells more effectively. Research has expanded to include embryonic, adult, and induced pluripotent stem cells (iPSCs), which are adult cells reprogrammed to behave like embryonic stem cells.

          Controversies surrounding stem cell therapies include ethical concerns and the risk of tumor development. Despite this, stem cell therapy remains one of the most promising avenues for extending human health span and addressing the root causes of aging.

          The 2010s-2020: A New Start

          Senolytic Drugs: 

          Senolytic drugs target and eliminate senescent cells that have stopped dividing but remain metabolically active, contributing to age-related diseases (53-55). Early senolytic agents like dasatinib and quercetin effectively eliminated senescent cells in aged mice. Senolytic drugs improve age-related conditions such as osteoarthritis, atherosclerosis, pulmonary fibrosis, and Alzheimer’s disease.

          Microbiome Research: 

          Advances in microbiome management revealed the gut microbiome’s influence on aging (56-58). A diverse and balanced microbiome is associated with healthy aging, while a decline in microbial diversity is linked to age-related diseases. Interventions like prebiotics, probiotics, and fecal microbiota transplants (FMT) modulate the gut microbiome to promote anti-aging.

          NAD+ Boosters:

          Nicotinamide adenine dinucleotide (NAD+) is crucial for cellular metabolism, DNA repair, and energy production (59-62). NAD+ levels decline with age, reducing the efficiency of these processes. Boosting NAD+ levels restores mitochondrial function, enhances DNA repair, and increases lifespan. NAD+ replenishment mitigates age-related diseases and improves muscle function, cognitive performance, and metabolic health.

          The 2020s (So Far)

          Most recently, I started to dive into the latest advancements in regenerative and anti-aging medicine, exploring innovative therapies and technologies that promise to extend health span and improve the quality of life.

          Advanced Regenerative Therapies:

          Advancements in regenerative medicine are revolutionizing stem cell therapies to repair age-related damage (63-65). Techniques like induced pluripotent stem cells (iPSCs) enable personalized regenerative treatments, using patients’ cells to create customized therapies. Tissue engineering and 3D bioprinting technology allow the creation of lab-grown tissues and organs, addressing donor organ shortages and reducing the risk of immune rejection.

          The GLP-1s Revisited: Semaglutide, Tirzepatide, and Retatrutide

              1. Semaglutide: Approved as Ozempic for type 2 diabetes, semaglutide lowers blood glucose levels and promotes weight loss (66). A higher-dose formula, Wegovy, is FDA-approved for chronic weight management. Side effects include nausea, vomiting, diarrhea, constipation, abdominal pain, headaches, and fatigue. We mitigate these issues by micro-dosing semaglutide and adding vitamin B6.

              1. Tirzepatide: This next-generation GLP-1 agonist targets both GLP-1 and GIP receptors, improving insulin secretion, inhibiting glucagon release, and slowing gastric emptying more effectively (67). Tirzepatide, marketed as Mounjaro, shows superior results compared to existing GLP-1 agonists.
                Retatrutide: Expected in 2025, retatrutide targets GLP-1, GIP, and glucagon receptors, providing enhanced benefits for weight reduction and glycemic control (68).

            What the Future Holds for the GLP-1s

            Since their introduction in 2005, GLP-1 agonists have evolved from oral agents to daily injectables to weekly injectables and back again in their evolving formulations and expanded indications. Research will likely focus on optimizing these drugs’ efficacy and safety profiles.  Combination therapies, such as tirzepatide and retatrutide, are almost a certainty. Oral agents, such as oral semaglutide (Rybelsus), significantly advance patient convenience and adherence.

            Innovations in delivery methods, such as implantable devices or long-acting injectables, promise to improve user experience and therapeutic outcomes. Moreover, ongoing studies are exploring the benefits of GLP-1 agonists beyond diabetes and obesity, including potential applications in cardiovascular health, neuroprotection, and anti-inflammatory effects, broadening their therapeutic scope and impact.

            Advancements in GLP-1 agonists like semaglutide, tirzepatide, and retatrutide underscore rapid progress in this field. These innovations enhance the management of metabolic diseases, improve patient quality of life, and potentially extend lifespan by addressing key aspects of metabolic health.

            Summary of Anti-Aging Medical Breakthroughs I Studied In My Career

            1970s:

            1980s

            1990s:

            2000s 

            2010s

            2020s

            Conclusion

            We are far from the Pritikin Clinic, our first anti-aging exposure. From telomeres to intermittent fasting to the rise of antioxidants, low-dose naltrexone, bioidentical hormone optimization, stem cell therapies, microbiome research, and NAD+ boosters, my colleagues and I have been at the forefront of most of these innovations.

            Throw in senolytic agents, rapamycin, the GLP-1s, and their advancements, and it’s been quite a journey. And know this: We included lifestyle factors, including anti-inflammatory diet regimens, stress management, and exercise, to improve our and our patients’ quality of life.

            I always joke, “If I didn’t find anti-aging medicine, I’d be an Uber driver.” (Not that there’s anything wrong with being an Uber driver.) 

            As I approach the fifty-year mark on my medical journey, I have more to accomplish before I’m done. Hopefully, I’ve built a foundation for the next generation of forward-thinking, innovative physicians to continue the advances I’ve witnessed and participated in.  

            I’ve had the time of my life.

            Sincerely,

            William Clearfield, D.O. H.M.D., F.A.A.F.R.M., F.A.A.M.A., D.A.B.M.A.

            References

                1.  Doozer sticks were a delicacy in the fictional Muppet Show spin-off, Fraggle Rock cuisine, and a staple of the Doozers’ diet, along with radishes.  https://muppet.fandom.com/wiki/Doozer_sticks

                1. https://www.linkedin.com/posts/jim-naccarato-dc-phd_white-hot-imperative-activity-7158529484659322880-Vz6Y/

                1. White A, Ernst E. A brief history of acupuncture. Rheumatology (Oxford). 2004 May;43(5):662-3. doi: 10.1093/rheumatology/keg005. PMID: 15103027.

                1. Lee J, Pellegrini MV. Biochemistry, Telomere And Telomerase. [Updated 2022 Dec 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK576429/

                1. Wilson et al. Blood leucocyte telomere DNA content predicts vascular telomere DNA content in humans with and without vascular disease. Eur Heart J 2008;29:2689-2694.

                1. Yokoo S, Furumoto K, Hiyama E, Miwa N. Slow-down of age-dependent telomere shortening is executed in human skin keratinocytes by hormesis-like-effects of trace hydrogen peroxide or by anti-oxidative effects of pro-vitamin C in common concurrently with reduction of intracellular oxidative stress. J Cell Biochem. 2004;93:588–597. doi:10.1002/jcb.20208

                1. Epel E, Blackburn E et al. Accelerated telomere shortening in response to life stress. Proc Natl Acad Sci USA 2004;101:17312-17315.

                1. Ornish D, Blackburn E, et al. Effect of comprehensive lifestyle changes on telomerase activity and telomere length in men and women with biopsy-proven low-risk prostate cancer: 5-year follow-up of a descriptive pilot study. Lancet Oncol 2013;14:1112-1120.

                1. Zvereva MI, Shcherbakova DM, Dontsova OA. Telomerase: structure, functions, and activity regulation. Biochemistry (Mosc). 2010 Dec;75(13):1563-83. doi: 10.1134/s0006297910130055. PMID: 21417995.

                1. https://www.pritikin.com/home-the-basics/about-pritikin/38-nathan-pritikin.html#:~:text=In%201975%2C%20Nathan%20Pritikin%20opened,%2C%20and%20lifestyle%2Dchange%20education.

                1. https://www.medicalnewstoday.com/articles/want-to-live-longer-healthier-lives-restricting-calorie-intake-may-help#How-can-reducing-calories-improve-health?

                1. https://www.nih.gov/news-events/news-releases/calorie-restriction-humans-builds-strong-muscle-stimulates-healthy-aging-genes#:~:text=Events%20%C2%BB%20News%20Releases-,News%20Releases,related%20diseases%20in%20animal%20models.

                1. Rusu ME, Fizeșan I, Vlase L, Popa DS. Antioxidants in Age-Related Diseases and Anti-Aging Strategies. Antioxidants (Basel). 2022 Sep 21;11(10):1868. doi: 10.3390/antiox11101868. PMID: 36290589; PMCID: PMC9598595.

                1. Zhao L, Cao J, Hu K, He X, Yun D, Tong T, Han L. Sirtuins and their Biological Relevance in Aging and Age-Related Diseases. Aging Dis. 2020 Jul 23;11(4):927-945. doi: 10.14336/AD.2019.0820. PMID: 32765955; PMCID: PMC7390530.

                1. Palacios, S., Stevenson, J. C., Schaudig, K., Lukasiewicz, M., & Graziottin, A. (2019). Hormone therapy for first-line management of menopausal symptoms: Practical recommendations. Women’s Health. https://doi.org/10.1177/1745506519864009

                1. Chlebowski RT, Manson JE, Anderson GL, Cauley JA, Aragaki AK, Stefanick ML, Lane DS, Johnson KC, Wactawski-Wende J, Chen C, Qi L, Yasmeen S, Newcomb PA, Prentice RL. Estrogen plus progestin and breast cancer incidence and mortality in the Women’s Health Initiative Observational Study. J Natl Cancer Inst. 2013 Apr 17;105(8):526-35. doi: 10.1093/jnci/djt043. Epub 2013 Mar 29. PMID: 23543779; PMCID: PMC3691942.

                1. Bihari B. Bernard Bihari, MD: low-dose naltrexone for normalizing immune system function. Altern Ther Health Med. 2013 Mar-Apr;19(2):56-65. PMID: 23594453.

                1. Sampson, J., Why Do We Need Endorphins? July 11, 2017 https://www.healthline.com/health/endorphins

                1. Pilozzi A, Carro C, Huang X. Roles of β-Endorphin in Stress, Behavior, Neuroinflammation, and Brain Energy Metabolism. Int J Mol Sci. 2020;22(1):338. Published 2020 Dec 30. doi:10.3390/ijms22010338

                1. https://ldnresearchtrust.org/hashimoto-thyroiditis-and-low-dose-naltrexone-ldn-paula-johnson

                1. Elsegood, L., “The LDN Book, Volume Two.” Chelsea Green Publishing, London, U.K., 2020, 199-200

                1. https://www.heart.org/en/news/2022/07/25/getting-more-exercise-than-guidelines-suggest-may-further-lower-death-risk#:~:text=People%20who%20reported%20meeting%20the,lower%20risk%2C%20the%20analysis%20found.

                1. Maria A. Fiatarone, Evelyn F. O’Neill, Nancy Doyle Ryan, Exercise Training and Nutritional Supplementation for Physical Frailty in Very Elderly People, June 23, 1994
                  N Engl J Med 1994;330:1769-1775 DOI: 10.1056/NEJM199406233302501

                1. Benedetti MG, Furlini G, Zati A, Letizia Mauro G. The Effectiveness of Physical Exercise on Bone Density in Osteoporotic Patients. Biomed Res Int. 2018 Dec 23;2018:4840531. doi: 10.1155/2018/4840531. PMID: 30671455; PMCID: PMC6323511.

                1. Smith PJ, Potter GG, McLaren ME, Blumenthal JA. Impact of aerobic exercise on neurobehavioral outcomes. Ment Health Phys Act. 2013 Oct;6(3):139-153. doi: 10.1016/j.mhpa.2013.06.008. PMID: 25674157; PMCID: PMC4321747.

                1. Reimers CD, Knapp G, Reimers AK. Does physical activity increase life expectancy? A review of the literature. J Aging Res. 2012;2012:243958. doi: 10.1155/2012/243958. Epub 2012 Jul 1. PMID: 22811911; PMCID: PMC3395188.

                1. Warburton DER, Nicol CW, Bredin SSD. Health benefits of physical activity: the evidence. CMAJ. 2006;174(6):801–809. 

                1. Brinkman JE, Tariq MA, Leavitt L, et al. Physiology, Growth Hormone. [Updated 2023 May 1]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. https://www.ncbi.nlm.nih.gov/books/NBK482141/

                1. Siebert DM, Rao AL. The Use and Abuse of Human Growth Hormone in Sports. Sports Health. 2018 Sep/Oct;10(5):419-426. doi: 10.1177/1941738118782688. Epub 2018 Jun 22. PMID: 29932857; PMCID: PMC6116101.

                1. https://www.history.com/this-day-in-history/first-successful-cloning-of-a-mammal

                1. Alberio R, Wolf E. 25th ANNIVERSARY OF CLONING BY SOMATIC-CELL NUCLEAR TRANSFER: Nuclear transfer and the development of genetically modified/gene edited livestock. Reproduction. 2021 Jun 11;162(1):F59-F68. doi: 10.1530/REP-21-0078. PMID: 34096507; PMCID: PMC8240728.

                1. https://longevinex.com/articles/

                1. Koushki, M., Amiri-Dashatan, N., Ahmadi, N., Abbaszadeh, H. A., & Rezaei-Tavirani, M. (2018). Resveratrol: A miraculous natural compound for disease treatment. Food science & nutrition, 6(8), 2473–2490. https://doi.org/10.1002/fsn3.855

                1. Koushki, M., Amiri-Dashatan, N., Ahmadi, N., Abbaszadeh, H. A., & Rezaei-Tavirani, M. (2018). Resveratrol: A miraculous natural compound for disease treatment. Food science & nutrition, 6(8), 2473–2490. https://doi.org/10.1002/fsn3.855

                1. Salehi, B., Mishra, A. P., Nigam, M., Sener, B., Kilic, M., Sharifi-Rad, M., Fokou, P. V. T., Martins, N., & Sharifi-Rad, J. (2018). Resveratrol: A Double-Edged Sword in Health Benefits. Biomedicines, 6(3), 91. https://doi.org/10.3390/biomedicines6030091

                1. González-Muniesa P., Mártinez-González M.-A., Hu F.B., Després J.-P., Matsuzawa Y., Loos R.J.F., Moreno L.A., Bray G.A., Martinez J.A. Obesity. Nat. Rev. Dis. Primers. 2017;3:17034. doi: 10.1038/nrdp.2017.34

                1. Miriam Méndez-del Villar, Manuel González-Ortiz, Esperanza Martínez-Abundis, Karina G. Pérez-Rubio, and Roberto Lizárraga-Valdez, Effect of Resveratrol Administration on Metabolic Syndrome, Insulin Sensitivity, and Insulin Secretion. Metabolic Syndrome and Related Disorders 2014 12:10, 497-501

                1. Maliszewska K, Kretowski A. Brown Adipose Tissue and Its Role in Insulin and Glucose Homeostasis. Int J Mol Sci. 2021;22(4):1530. Published 2021 Feb 3. doi:10.3390/ijms22041530

                1. http://www.centerwatch.com/drug-information/fda-approved-drugs/drug/772/botox-cosmetic-botulinum-toxin-type-a

                1. http://www.centerwatch.com/drug-information/fda-approved-drugs/drug/772/botox-cosmetic-botulinum-toxin-type-a

                1. https://www.isaps.org/discover/about-isaps/global-statistics/reports-and-press-releases/global-survey-2022-full-report-and-press-releases/#:~:text=I%20think%20this%20is%20largely,procedures%20decreased%20to%204.3%20million.

                1. Ballou LM, Lin RZ. Rapamycin and mTOR kinase inhibitors. J Chem Biol. 2008 Nov;1(1-4):27-36. doi: 10.1007/s12154-008-0003-5. Epub 2008 May 15. PMID: 19568796; PMCID: PMC2698317.

                1. Lotfimehr H, Mardi N, Narimani S, Nasrabadi HT, Karimipour M, Sokullu E, Rahbarghazi R. mTOR signalling pathway in stem cell bioactivities and angiogenesis potential. Cell Prolif. 2023 Dec;56(12):e13499. doi: 10.1111/cpr.13499. Epub 2023 May 8. PMID: 37156724; PMCID: PMC10693190.

                1. Treder N, Plenis A, Maliszewska O, Kaczmarczyk N, Olędzka I, Kowalski P, Bączek T, Bień E, Krawczyk MA, Roszkowska A. Monitoring of sirolimus in the whole blood samples from pediatric patients with lymphatic anomalies. Open Med (Wars). 2023 Mar 2;18(1):20230652. doi: 10.1515/med-2023-0652. PMID: 36874365; PMCID: PMC9982740.

                1. Unnikrishnan A, Kurup K, Salmon AB, Richardson A. Is Rapamycin a Dietary Restriction Mimetic? J Gerontol A Biol Sci Med Sci. 2020 Jan 1;75(1):4-13. doi: 10.1093/gerona/glz060. PMID: 30854544; PMCID: PMC6909904.

                1. Drucker DJ, Habener JF, Holst JJ. Discovery, characterization, and clinical development of the glucagon-like peptides. J Clin Invest. 2017 Dec 1;127(12):4217-4227. doi: 10.1172/JCI97233. Epub 2017 Dec 1. PMID: 29202475; PMCID: PMC5707151.

                1. Bridges A, Bistas KG, Jacobs TF. Exenatide. [Updated 2023 May 29]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK518981/

                1. https://www.drugs.com/mtm/liraglutide.html

                1. Iorga RA, Bacalbasa N, Carsote M, Bratu OG, Stanescu AMA, Bungau S, Pantis C, Diaconu CC. Metabolic and cardiovascular benefits of GLP-1 agonists, besides the hypoglycemic effect (Review). Exp Ther Med. 2020 Sep;20(3):2396-2400. doi: 10.3892/etm.2020.8714. Epub 2020 May 5. PMID: 32765722; PMCID: PMC7401476.

                1. Zakrzewski W, Dobrzyński M, Szymonowicz M, Rybak Z. Stem cells: past, present, and future. Stem Cell Res Ther. 2019 Feb 26;10(1):68. doi: 10.1186/s13287-019-1165-5. PMID: 30808416; PMCID: PMC6390367.

                1. Liu L, Rando TA. Manifestations and mechanisms of stem cell aging. J Cell Biol. 2011 Apr 18;193(2):257-66. doi: 10.1083/jcb.201010131. PMID: 21502357; PMCID: PMC3080271.

                1. https://www.advancedrejuvenation.us/hines-ward-receives-prp-to-his-knee-before-becoming-super-bowl-mvp/

                1. Hickson LJ, Langhi Prata LGP, Bobart SA, Evans TK, Giorgadze N, Hashmi SK, Herrmann SM, Jensen MD, Jia Q, Jordan KL, Kellogg TA, Khosla S, Koerber DM, Lagnado AB, Lawson DK, LeBrasseur NK, Lerman LO, McDonald KM, McKenzie TJ, Passos JF, Pignolo RJ, Pirtskhalava T, Saadiq IM, Schaefer KK, Textor SC, Victorelli SG, Volkman TL, Xue A, Wentworth MA, Wissler Gerdes EO, Zhu Y, Tchkonia T, Kirkland JL. Senolytics decrease senescent cells in humans: Preliminary report from a clinical trial of Dasatinib plus Quercetin in individuals with diabetic kidney disease. EBioMedicine. 2019 Sep;47:446-456. doi: 10.1016/j.ebiom.2019.08.069. Epub 2019 Sep 18. Erratum in: EBioMedicine. 2020 Feb;52:102595. doi: 10.1016/j.ebiom.2019.12.004. PMID: 31542391; PMCID: PMC6796530.

                1. Zhu Y, Doornebal EJ, Pirtskhalava T, Giorgadze N, Wentworth M, Fuhrmann-Stroissnigg H, Niedernhofer LJ, Robbins PD, Tchkonia T, Kirkland JL. New agents that target senescent cells: the flavone, fisetin, and the BCL-XL inhibitors, A1331852 and A1155463. Aging (Albany NY). 2017 Mar 8;9(3):955-963. doi: 10.18632/aging.101202. PMID: 28273655; PMCID: PMC5391241.

                1. Chaib, S., Tchkonia, T. & Kirkland, J.L. Cellular senescence and senolytics: the path to the clinic. Nat Med 28, 1556–1568 (2022). https://doi.org/10.1038/s41591-022-01923-y

                1. Salazar J, Durán P, Díaz MP, Chacín M, Santeliz R, Mengual E, Gutiérrez E, León X, Díaz A, Bernal M, Escalona D, Hernández LAP, Bermúdez V. Exploring the Relationship between the Gut Microbiota and Ageing: A Possible Age Modulator. Int J Environ Res Public Health. 2023 May 17;20(10):5845. doi: 10.3390/ijerph20105845. PMID: 37239571; PMCID: PMC10218639

                1. Deng F, Li Y, Zhao J. The gut microbiome of healthy long-living people. Aging (Albany NY). 2019 Jan 15;11(2):289-290. doi: 10.18632/aging.101771. PMID: 30648974; PMCID: PMC6366966.

                1. Boehme M, Guzzetta KE, Wasén C, Cox LM. The gut microbiota is an emerging target for improving brain health during ageing. Gut Microbiome (Camb). 2023;4:E2. doi: 10.1017/gmb.2022.11. Epub 2022 Dec 12. PMID: 37179659; PMCID: PMC10174391.

                1. Covarrubias AJ, Perrone R, Grozio A, Verdin E. NAD+ metabolism and its roles in cellular processes during ageing. Nat Rev Mol Cell Biol. 2021 Feb;22(2):119-141. doi: 10.1038/s41580-020-00313-x. Epub 2020 Dec 22. PMID: 33353981; PMCID: PMC7963035.

                1. Imai S, Guarente L. NAD+ and sirtuins in aging and disease. Trends Cell Biol. 2014 Aug;24(8):464-71. doi: 10.1016/j.tcb.2014.04.002. Epub 2014 Apr 29. PMID: 24786309; PMCID: PMC4112140.

                1. Lautrup S, Sinclair DA, Mattson MP, Fang EF. NAD+ in Brain Aging and Neurodegenerative Disorders. Cell Metab. 2019 Oct 1;30(4):630-655. doi: 10.1016/j.cmet.2019.09.001. PMID: 31577933; PMCID: PMC6787556.

                1. Mukherjee S, Ray D, Lekli I, Bak I, Tosaki A, Das DK. Effects of Longevinex (modified resveratrol) on cardioprotection and its mechanisms of action. Can J Physiol Pharmacol. 2010 Nov;88(11):1017-25. doi: 10.1139/y10-082. PMID: 21076489.

                1. Chehelgerdi M, Behdarvand Dehkordi F, Chehelgerdi M, Kabiri H, Salehian-Dehkordi H, Abdolvand M, Salmanizadeh S, Rashidi M, Niazmand A, Ahmadi S, Feizbakhshan S, Kabiri S, Vatandoost N, Ranjbarnejad T. Exploring the promising potential of induced pluripotent stem cells in cancer research and therapy. Mol Cancer. 2023 Nov 28;22(1):189. doi: 10.1186/s12943-023-01873-0. PMID: 38017433; PMCID: PMC10683363.

                1. Yaneva A, Shopova D, Bakova D, Mihaylova A, Kasnakova P, Hristozova M, Semerdjieva M. The Progress in Bioprinting and Its Potential Impact on Health-Related Quality of Life. Bioengineering (Basel). 2023 Aug 1;10(8):910. doi: 10.3390/bioengineering10080910. PMID: 37627795; PMCID: PMC10451845.

                1. Bagno L, Hatzistergos KE, Balkan W, Hare JM. Mesenchymal Stem Cell-Based Therapy for Cardiovascular Disease: Progress and Challenges. Mol Ther. 2018 Jul 5;26(7):1610-1623. doi: 10.1016/j.ymthe.2018.05.009. Epub 2018 May 25. PMID: 29807782; PMCID: PMC6037203.

                1. Wilding, J.P.H. Batterham, R.L.,  “Once-Weekly Semaglutide in Adults with Overweight or Obesity” March 18, 2021 N Engl J Med 2021; 384:989-1002 DOI: 10.1056/NEJMoa2032183

                1. Farzam K, Patel P. Tirzepatide. [Updated 2024 Feb 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK585056/

                1. Sanyal, A.J., Kaplan, L.M., Frias, J.P. et al. Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial. Nat Med (2024). https://doi.org/10.1038/s41591-024-03018-2