Critically Speaking

What if the biggest risk factor for cancer, heart disease, and dementia isn't your genes, diet, or blood pressure but aging itself? Listen in as biogerontologist Dr. Matt Kaeberlein reveals how understanding the biology of aging could add not just years to our lives, but healthy decades, and why your dog might hold some of the most important clues. In this episode, Therese Markow and Dr. Matt Kaeberlein discuss aging research. He explains that aging is characterized by damage accumulation and loss of resilience, leading to functional decline. Matt highlights the hallmarks of aging, such as deregulation of nutrient sensing and DNA damage, and the potential of interventions like rapamycin to slow aging. He notes that biological age is a significant risk factor for major diseases, and that understanding and addressing aging biology could significantly extend human lifespan. They also discuss the Dog Aging Project, with 55,000 participating dogs, which aims to uncover genetic and environmental factors influencing health and longevity in pets. Key Takeaways: Our bodies are constantly being exposed to stress, and stress can move us out of the optimal zone of function. When we're young, we're very resilient and able to come back to optimal function. As we get older, we lose that resilience. When we slow aging in laboratory animals, we prevent the onset and progression of all of the major age-related functional declines and diseases simultaneously, because we've slowed biological aging. Based on what's possible in mice, it is estimated that we could potentially gain 2-3 additional decades of life if we can achieve this in humans. There is a genetic component to longevity; however, how big that genetic component is to longevity is hotly debated. The environment is also a large contributor. "Biological age is the single greatest risk factor for nine of the top 10 killers in the United States, and it's not a small effect. The magnitude of effect from biological aging dwarfs all of the other risk factors combined…it's useful to appreciate how important biological age is to the risk of developing many of the chronic diseases and functional declines that limit quality and quantity of life for most people." — Dr. Matt Kaeberlein Episode References: Dog Aging Project: https://dogagingproject.org/ Dog Aging Institute: https://dogaginginstitute.org/ Longevity for Dogs: https://www.youtube.com/@LongevityForDogs Connect with Dr. Matt Kaeberlein: Professional Bio: https://halo.dlmp.uw.edu/people/matt-kaeberlein/ Publications: https://pubmed.ncbi.nlm.nih.gov/?term=%22kaeberlein+m%22[author] YouTube: https://www.youtube.com/@mkaeberlein LinkedIn: https://www.linkedin.com/in/mkaeberlein/ Connect with Therese: Website: www.criticallyspeaking.net Bluesky: @CriticallySpeaking.bsky.social Instagram: @criticallyspeakingpodcast Email: theresemarkow@criticallyspeaking.net Audio production by Turnkey Podcast Productions. You're the expert. Your podcast will prove it.

Peptides are being sold online as miracle fixes for energy, healing, and longevity—but what if the science behind them is shaky, or even dangerous? In this episode, Therese Markow and Dr. Leigh Baxt pull back the curtain on the peptide craze, revealing what we really know (and don't know) about these heavily marketed "biohacks." They discuss the complexities and risks of unapproved peptides, which are often marketed for health enhancement. Dr. Baxt explains what peptides are and speaks to those drugs that are FDA-approved, like GLP-1 agonists and insulin, but also highlights the safety concerns of unapproved peptides, such as BPC-157 and TB-500, which lack appropriate clinical trial data and are often synthesized in unregulated labs. Dr. Baxt emphasizes the importance of proper clinical trial processes and regulatory oversight to ensure drug safety and efficacy. Key Takeaways: A peptide is just a short chain of amino acids. They can be created synthetically, they can be isolated, and they are natural. The body doesn't care whether a peptide is "natural" or synthetic; what matters is its exact molecular structure. FDA-approved peptide drugs go through years of rigorous testing in animals and humans to prove both safety and effectiveness before reaching the market. Calling something "scientifically proven" can be misleading when the underlying evidence is weak, preliminary, or based only on rat studies. Especially as much of the "science" cited on peptide marketing sites comes from small, limited animal, or cell studies, not large, controlled human trials. Just because a product is available online or from a compounding pharmacy does not mean it is FDA-approved, well-studied, or safe; consumers must look beyond hype and ask what evidence truly exists. A naturally occurring peptide is generally not going to be suitable for use therapeutically. "You can say that something is scientifically demonstrated because it showed something interesting in a rat. The key is that the people may not ask that, because a lot of times people hear 'scientific terminology' and it makes something sound really legitimate, but it doesn't mean that there's solid data." — Dr. Leigh Baxt Evaluation of Research Grade Peptides Marketed Directly to Consumers Reveals Extensive Variability in Purity and Measured Abundance: https://www.preprints.org/manuscript/202604.1748 Connect with Dr. Leigh Baxt: Professional Bio: https://www.mskcc.org/profile/leigh-baxt LinkedIn: https://www.linkedin.com/in/leigh-baxt-314b877 Connect with Therese: Website: www.criticallyspeaking.net Bluesky: @CriticallySpeaking.bsky.social Instagram: @criticallyspeakingpodcast Email: theresemarkow@criticallyspeaking.net Audio production by Turnkey Podcast Productions. You're the expert. Your podcast will prove it.

Our cities are anything but concrete jungles. Listen in as Therese Markow and Dr. Dan Werb reveal the hidden world of synanthropes - the wild animals that not only live alongside us, but thrive because of us. In this episode, Therese Markow and Dr. Dan Werb discuss Dan's new book "Our Wild Familiars", which explores how animals (and plants) adapt to urban environments. They dive into the history and impact of synanthropes, such as raccoons, coyotes, and rats. He also highlights the adaptability of these animals and why they have expanded into cities. Dr. Werb emphasizes the importance of viewing cities as living, thriving ecosystems and the need for human ecosystem-based solutions for the good of humans and animals alike in these ecosystems. Key Takeaways: Humanity has a much higher risk of experiencing viral spillover events now than before, because we are increasingly intersecting with wild animals that we have never seen before in urban spaces that carry pathogens that we've never been exposed to before. As humans, we have a relationship with synanthropes that is so deep and long-standing that it has become central to our spiritual selves as well. With more small animals being drawn into cities, that is going to continue to draw in more predators, such as coyotes, which have expanded their home range by about 50 kilometers per year for the last 150-200 years. It may be impossible to eliminate any synanthrope that has found an ecosystem within a city. Even if you remove one creature from an area, the niche they had developed will still be there, ready for the next synanthrope to move in. Solutions that make life better for humans can actually be profoundly beneficial for animals as well, or at least for the functioning of our urban ecosystems. "Cities are more biodiverse than the areas that surround them, and that's because humans, like any other organism, want to live in places that are as fertile and rich as possible." — Dr. Dan Werb Connect with Dr. Dan Werb: Professional Bio: https://ihpme.utoronto.ca/faculty-profile/dan-werb/, https://profiles.ucsd.edu/daniel.werb Website: https://danwerb.substack.com/ Instagram: https://www.instagram.com/danwerb/ Books: PREORDER: Our Wild Familiars - https://www.penguinrandomhouse.com/books/769255/our-wild-familiars-by-dan-werb/ City of Omens - https://www.amazon.com/City-Omens-Search-Missing-Borderlands-ebook/dp/B07QLN4K3T The Invisible Siege - https://www.penguinrandomhouse.com/books/670859/the-invisible-siege-by-dan-werb/ Connect with Therese: Website: www.criticallyspeaking.net Bluesky: @CriticallySpeaking.bsky.social Instagram: @criticallyspeakingpodcast Email: theresemarkow@criticallyspeaking.net Audio production by Turnkey Podcast Productions. You're the expert. Your podcast will prove it.

Long COVID isn't just lingering fatigue. It's a complex, often life-altering condition that can follow even mild or unnoticed infections. Listen in as Mayo Clinic's Dr. Stephanie Grach breaks down what we really know about Long COVID, who's at risk, and why believing and individualizing care for patients is absolutely critical. In this episode, Therese Markow and Dr. Stephanie Grach discuss the emergence and impact of Long COVID. Dr. Grach explains that Long COVID affects an estimated 18 million Americans with a wide variety of symptoms that can manifest differently from patient to patient, influenced by a variety of factors, such as viral variant, genetics, and immune responses. Dr. Grach emphasizes the importance of individualized treatment and highlights ongoing research and the need for better understanding and management of this complex chronic condition. Key Takeaways: Long COVID can look very different from person to person, with over 200 symptoms. However, common symptoms can include fatigue, brain fog, shortness of breath, changes in smell, and more, affecting nearly every organ system. The larger proportion of people with Long COVID had multiple COVID infections, partly because of sheer numbers - each additional infection is another opportunity for post-acute symptoms to develop or worsen. The presentation of the Long COVID symptoms is not going to be consistent - patients may have good weeks and feel pretty close to normal, as well as bad weeks, where the symptoms are at their strongest. Telling someone to "push through" on the assumption that it will just get better really isn't what helps the Long COVID patients. "Long COVID is real. Patients deserve to be believed, and treatment should be individualized, rather than trying to fit or wait for a one-size-fits-all." — Dr. Stephanie Grach Connect with Dr. Stephanie Grach: Professional Bio: https://www.mayoclinic.org/biographies/grach-stephanie-l-m-d-m-s/bio-20536370 LinkedIn: https://www.linkedin.com/in/stephaniegrach Connect with Therese: Website: www.criticallyspeaking.net Bluesky: @CriticallySpeaking.bsky.social Instagram: @criticallyspeakingpodcast Email: theresemarkow@criticallyspeaking.net Audio production by Turnkey Podcast Productions. You're the expert. Your podcast will prove it.

Ru Marshall pulls back the curtain on the man behind the myth of Carlos Castaneda, exposing the real lives, lies, and losses buried beneath his legendary books. In this episode, Therese Markow and Ru Marshall discuss the life and legacy of Carlos Castaneda, who claimed to have been trained as a shaman by Don Juan. Castaneda's books, which sold over 8 million copies, were initially believed but later dismissed as fiction. Marshall's book, "American Trickster," explores Castaneda's origins in Peru and his life in the U.S. Castaneda, born Cesar Arana, was a charismatic storyteller who seduced both women and academics. Despite initial academic support, his claims were eventually debunked. Ru's research spanned 20 years, revealing Castaneda's complex personal life and the impact of his cult-like following. Key Takeaways: Long before the books, Carlos Castaneda was known as a gifted storyteller and trickster, blurring the line between entertainment, fabrication, and manipulation. Castaneda's real power was psychological. He made individuals, especially women, feel uniquely seen, chosen, and special, a classic mechanism of charismatic control. The disappearance and deaths of key followers after Castaneda's passing reveal the devastating human cost when a closed belief system collides with reality. And when followers are willing to follow a narrative all the way to the end. "It's a really interesting thing, that when people, both professionally and, more importantly, I think, emotionally, become invested in a belief, it is incredibly hard for people to admit they're wrong." — Ru Marshall Connect with Ru Marshall: Website: https://rmarshallstudio.com/ Threads: https://www.threads.com/@robtmars Instagram: https://www.instagram.com/robtmars/ American Trickster: The Hidden Lives of Carlos Castaneda: https://orbooks.com/catalog/american-trickster/ Connect with Therese: Website: www.criticallyspeaking.net Bluesky: @CriticallySpeaking.bsky.social Instagram: @criticallyspeakingpodcast Email: theresemarkow@criticallyspeaking.net Audio production by Turnkey Podcast Productions. You're the expert. Your podcast will prove it.

When a globally respected infectious disease expert is abruptly sidelined by an anti‑vaccine administration, what does it reveal about the future of public health and scientific integrity? In this episode, Therese Markow and Dr. Jeanne Marrazzo discuss her termination and whistleblower lawsuit against the U.S. government. She highlighted NIAID's critical role in infectious disease research, funding $6.6 billion annually. Dr. Marrazzo criticized the new administration's anti-vaccine stance, cessation of global HIV/AIDS funding, and termination of clinical trials, which she argued endangered public health. Dr. Marrazzo filed a whistleblower complaint in September 2025, leading to her firing in October. She now leads the Infectious Disease Society of America, advocating for evidence-based policies and scientific integrity. Key Takeaways: Tuberculosis (TB, formerly known as Consumption) is now the top global killer as an infectious disease. Shutting down clinical trials and cutting international research funding mid‑stream doesn't just waste taxpayer dollars; it endangers patients who rely on those therapies and violates core ethical standards. Political ideology overriding scientific evidence can rapidly dismantle decades of progress in vaccines, global health research, and public trust. Independent professional societies and medical organizations now play a critical role in evidence above ideology, preserving rigorous guidelines, publishing unbiased research, and speaking truth to power when government agencies are silenced or hollowed out. "What I don't think people realize is the power of the platform that the Secretary and indeed the President have. The tragic part about this is that we've spent decades building up that trust, trying to make sure that it was justified, and to see that just summarily destroyed, there's no other word for it, is really, really tragic. I don't know what it's going to take to build it up again." — Jeanne Marrazzo, MD Connect with Jeanne: Professional Bio: https://www.niaid.nih.gov/about/jeanne-marrazzo-md-mph Website: https://www.idsociety.org/ LinkedIn: https://www.linkedin.com/in/jeanne-marrazzo-203463179 Connect with Therese: Website: www.criticallyspeaking.net Bluesky: @CriticallySpeaking.bsky.social Instagram: @criticallyspeakingpodcast Email: theresemarkow@criticallyspeaking.net Audio production by Turnkey Podcast Productions. You're the expert. Your podcast will prove it.

In this episode, Therese Markow and Dorothy Roberts discuss her book "The Mixed Marriage Project," which explores her father's unpublished research on mixed marriages in Chicago. Dorothy's father, a white anthropology professor, interviewed over 500 black-white couples from the 1930s to the 1960s. The book blends personal stories, historical insights, and interviews, revealing the challenges and discrimination faced by interracial couples. They also discuss Dorothy's mother's remarkable journey from Jamaica to Chicago and the impact of her parents' interracial marriage on her life. The book highlights systemic racism and the one-drop rule, emphasizing the need for societal love and equality. Key Takeaways: All black movements can be linked back to the Marcus Garvey Movement, which started in Jamaica. Even within early mixed marriages and organizations for these couples, such as the Manassas Club, there were harmful stereotypes within these groups. To interracial couples, the biggest barrier was the barrier of the black belt that was created by racially restricted covenants and mob violence against black people. "The One-Drop Rule was instituted to support white supremacy, and also it proves that race is not a natural division of human beings. Who is black, who is white, depends entirely on social rules, which might be instituted in law, or they're just part of societal norms and expectations. But they're not biological, they're not natural. They're made up." — Dorothy Roberts Connect with Dorothy Roberts: Professional Bio: https://www.law.upenn.edu/faculty/roberts1 Website: https://www.dorothyeroberts.com/ Book: https://www.simonandschuster.com/books/The-Mixed-Marriage-Project/Dorothy-Roberts/9781668068380 Connect with Therese: Website: www.criticallyspeaking.net Bluesky: @CriticallySpeaking.bsky.social Instagram: @criticallyspeakingpodcast Email: theresemarkow@criticallyspeaking.net Audio production by Turnkey Podcast Productions. You're the expert. Your podcast will prove it.

In this episode, Therese Markow and Dr. Haley Hersant discuss a study by Dr. Hersant and her colleagues that reviewed over 100 brain and memory supplements. They found 18 common ingredients grouped into three categories: those with scientific evidence of benefit, those with no compelling evidence, and those with mixed results. They discuss the results of this study and emphasize the need for more rigorous testing. While not giving medical advice, they caution against potential interactions with prescription medications and advise listeners to do their research as well as talk to their own providers. Key Takeaways: The most common factor across all of these ingredients that had some benefit is that, theoretically, they are known to decrease inflammation and help activate cellular repair pathways. The FDA does not have the authority to approve dietary supplements before they are put on the market, so it primarily regulates them once they are already on the market. This is different from traditional pharmaceuticals. If you are taking supplements, do report them when completing a medical history with your doctor, as they can interact with your prescriptions, vitamins, and other supplements. "For many people, it could be harmless to be taking these supplements. They may be wasting their money without getting much benefit. But health-wise, they may be okay. However, whenever you start mixing a lot of different supplements, or are taking supplements with prescription medications, there are certainly some risks that can come into play." — Dr. Haley Hersant Episode References: Over the Counter Supplements for Memory: A Review of Available Evidence Connect with Dr. Haley Hersant: LinkedIn: https://www.linkedin.com/in/haley-hersant-79a0b12a4/ Connect with Therese: Website: www.criticallyspeaking.net Bluesky: @CriticallySpeaking.bsky.social Instagram: @criticallyspeakingpodcast Email: theresemarkow@criticallyspeaking.net Audio production by Turnkey Podcast Productions. You're the expert. Your podcast will prove it.