What Actually Slows Aging? The Science vs. Hype | Dr. David Barzilai

What if cognitive decline isn't always a one-way street? For decades, the conventional approach to Alzheimer's disease and cognitive impairment has focused largely on slowing progression. But emerging research is challenging that assumption—and raising important questions about what may be possible when we address the multiple factors contributing to brain dysfunction. In this episode of New Frontiers in Functional Medicine, Dr. Kara Fitzgerald welcomes Dr. Dale Bredesen and Dr. Kat Toups to discuss their recently completed randomized controlled trial investigating a personalized, systems-based approach to cognitive decline. The nine-month study enrolled 73 participants across six sites and reported significant improvements in several measures of cognitive function, including memory, processing speed, and overall neurocognitive performance. The conversation goes beyond the headline results to examine the metabolic, inflammatory, hormonal, infectious, and environmental factors that may contribute to cognitive impairment. They also explore a surprising finding: cognitive improvements were not accompanied by equally dramatic changes in traditional Alzheimer's blood biomarkers, raising questions about how we measure meaningful recovery. From ketogenic nutrition and exercise to sleep optimization, hormone health, targeted testing, and multidisciplinary coaching, Drs. Bredesen and Toups share the clinical thinking behind their precision medicine protocol, what the trial revealed, and what researchers still need to understand. For clinicians working in functional medicine, brain health, and longevity—and anyone interested in the evolving science of Alzheimer's prevention and cognitive health—this episode offers a compelling look at the possibilities and remaining questions surrounding personalized interventions for cognitive decline. In this episode of New Frontiers, learn about: A New Randomized Trial for Cognitive Decline: What a nine-month, 73-participant study revealed about personalized precision medicine, including improvements in memory, processing speed, and overall cognitive function compared with standard care. Reversing Cognitive Decline vs. Slowing Progression: Why Drs. Bredesen and Toups believe a systems-based approach may offer opportunities beyond conventional symptom management—and what the results do and don't establish. The Alzheimer's Biomarker Paradox: Why substantial cognitive improvements occurred without equally significant changes in amyloid-related and other blood biomarkers, including p-tau217, GFAP, and neurofilament light. The Hidden Contributors to Cognitive Impairment: How metabolic dysfunction, chronic inflammation, infections, environmental toxins, and other potential treatment targets were evaluated within the study's personalized protocol. Nutrition, Exercise, and Sleep for Brain Health: How a plant-rich ketogenic diet, aerobic and resistance exercise, sleep apnea screening, glucose monitoring, and cognitive training were incorporated into the intervention. Hormones, Menopause, and Cognitive Function: Why estrogen, progesterone, testosterone, and other hormones were considered important components of the protocol, particularly in the context of age-related cognitive changes. Infections, Mold, and Environmental Exposures: What the investigators observed when evaluating herpesviruses, tick-borne infections, mycotoxins, heavy metals, and other exposures—and why more analysis is needed to determine their individual contributions. The Role of Health Coaching and Personalized Care: Why nutritionists, exercise specialists, health coaches, and trained clinicians were essential to implementing a complex intervention and supporting patient adherence. The Future of Alzheimer's Prevention and Precision Medicine: How early cognitive assessment, individualized treatment, additional research, and integration into healthcare systems could reshape approaches to brain health and healthy aging.

Sauna is everywhere in the longevity conversation, but are all saunas actually doing the same thing? In this episode, Dr. Kara Fitzgerald sits down with Sunlighten co-founder Connie Zack to unpack the science of infrared sauna vs. traditional Finnish sauna, how different wavelengths of infrared and red light interact with the body, and what the research suggests about cardiovascular health, mitochondrial function, recovery, metabolism, and healthy aging. They explore the important distinction between heat therapy and light therapy, including far-, mid-, and near-infrared wavelengths and red light, why wavelength, dose, and proximity matter, and how these modalities may be used together. They also discuss practical sauna protocols, including how long and how often to use infrared sauna, and why hotter isn't necessarily better. In this episode, you'll learn: How infrared sauna differs from traditional Finnish sauna Why heat therapy and light therapy affect the body differently The differences between far-, mid-, and near-infrared light How near-infrared and red light interact with mitochondria and cellular energy What research suggests about infrared sauna and cardiovascular function Emerging research on photobiomodulation and metabolic health How long and how often to use infrared sauna Why hydration, minerals, dose, and personalization matter Whether combining infrared heat with near-infrared and red light may offer additional benefits

In this episode of New Frontiers in Functional Medicine, Dr. Kara Fitzgerald sits down with neuroscientist and mitochondrial health researcher Dr. Siobhan Mitchell to explore emerging research on mitochondrial dysfunction, aging, and longevity. They discuss how mitochondria change as we age, how mitochondrial dysfunction may contribute to chronic inflammation and age-related disease, and why supporting mitochondrial health could be an important strategy for extending healthspan. The conversation explores the relationship between mitochondrial dysfunction and biological aging, inflammation, cardiovascular and metabolic health, cognitive decline, and chronic disease. Dr. Mitchell also discusses emerging biomarkers of mitochondrial stress, including GDF-15, and what they may reveal about mitochondrial health and aging trajectories. Dr. Fitzgerald and Dr. Mitchell also examine practical and emerging approaches to supporting mitochondrial function, including creatine, NAD+ precursors, S-equol, exercise, and targeted mitochondrial support, along with research on vascular function, cellular energy production, and mitochondrial DNA damage. In this episode, you’ll learn: How mitochondrial dysfunction may contribute to inflammation and accelerated aging Why mitochondrial DNA damage could play a role in chronic disease What GDF-15 may reveal about mitochondrial stress and aging How creatine supports cellular and brain energy The connection between estrogen, S-equol, and mitochondrial health What emerging research says about NAD+ precursors and aging How targeted mitochondrial support may influence vascular health, exercise recovery, and cellular function

GLP-1 receptor agonists have transformed weight loss and metabolic health—but what are we overlooking? In this episode of New Frontiers in Functional Medicine, Dr. Kara Fitzgerald is joined by Dr. Sanjay Bhojraj and Dr. Alexis Gonzales to explore the clinical tradeoffs of GLP-1 therapy, including lean muscle preservation, nutrient status, weight regain, and long-term metabolic health.

Longevity medicine is expanding beyond biological age, biomarkers, and emerging technology. In this special episode of New Frontiers in Functional Medicine, Dr. Kara Fitzgerald shares four thought-provoking conversations exploring the science, clinical tools, and deeply human questions shaping the future of healthspan.