Roughly 90% of Alzheimer's patients develop neuropsychiatric symptoms including anxiety, persistent fear, and an inability to recognize safety — but little research is being done to investigate why. New data connecting PTSD, trauma, and accelerated brain aging may hold the answer.

Dr. Caesar Hernandez is a behavioral, molecular, and circuit neuroscientist and assistant professor in the Division of Gerontology, Geriatrics & Palliative Care at the University of Alabama at Birmingham. His research program seeks to identify modifiable mechanisms that drive vulnerability to age-related cognitive decline and Alzheimer's disease.

In this conversation with Dr. Dominic D'Agostino, Dr. Hernandez walks through epidemiological evidence linking PTSD to increased Alzheimer's risk, the comorbidity cluster of metabolic syndrome, gut permeability, and neuropsychiatric disorders observed in veteran populations, and why ketogenic interventions may offer a unique therapeutic angle — reducing neuroinflammation and anxiety while making the brain more receptive to rewiring traumatic memories.

Questions Answered in This Episode:

• Could addressing PTSD in midlife meaningfully reduce the risk of cognitive decline and dementia later in life?
• Why do veteran populations show such high comorbidity between PTSD, metabolic syndrome, and dementia?
• Could ketogenic therapy serve a similar function to pharmacologically-assisted psychotherapy for PTSD?
• How does the amygdala - the brain's "fear center" - play a role in Alzheimer's disease?
• What is the single biggest unanswered question driving Alzheimer's research right now — and why does it go beyond genetics and biochemistry?

Dr. Hernandez's driving question — why are negative life experiences associated with an increased the risk of neurodegeneration? — reframes brain aging as something shaped not just by genes and biology, but by the lives we live and the stress we carry.

Find more of Dr. Caesar Hernandez online:

• University of Alabama Birmingham
• LinkedIn

Special thanks to the sponsors of this episode:

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In every episode of The Metabolic Link, we'll uncover the very latest research on metabolic health and therapy. If you like this episode, please share it, subscribe, follow, and leave us a comment or review on whichever platform you use to tune in!

You can find us on all your major podcast players here and full episodes are also up on our Metabolic Health Summit YouTube channel!

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Please keep in mind: The Metabolic Link does not provide medical or health advice, but rather general information that does not serve as a substitute for a licensed healthcare professional. Never delay in seeking medical advice from an appropriately licensed medical provider for any health condition that you may have.

What if the sequence we've always assumed—plaque causes arterial stiffness—is actually backwards? Dr. Lily Johnston proposes that impaired nitric oxide signaling may stiffen arteries first, creating the endothelial injury that then promotes plaque formation.

Dr. Lily Johnston is a board-certified vascular surgeon and newly certified obesity medicine physician who bridges the operating room and metabolic medicine. After years of scraping plaque from arterial walls, she began questioning why surgical outcomes remain so modest—and discovered that what she was treating might represent the end stage of multiple distinct disease phenotypes, not a single condition.

In this episode, Dr. Johnston shares her forest fire analogy for understanding LDL risk, explains why tissue surrounding diseased arteries shows profound inflammation even in first-time surgeries, and reveals why 80–90% of the operations she performs could potentially be prevented with upstream metabolic intervention.

Questions Answered in This Episode:

• Do metabolically healthy people with elevated LDL need the same treatment as those with active disease?
• Why might someone with "great" biomarkers still have significant plaque burden?
• What will individualized cardiovascular treatment look like in 20 years?
• To what extent is vascular disease a metabolic disease—and is this accepted in vascular surgery?
• Where do you stand on the LDL particle number vs. metabolic context debate?
• What percentage of vascular surgeries could have been avoided with earlier metabolic intervention?

A surgeon's-eye view of what happens when metabolic dysfunction goes unaddressed for decades—and a practical framework for intervening before the fire starts.

Find more of Dr. Johnston online:

• Live Q&A
• Youtube channel
• LinkedIn
• Coresight Health

Special thanks to the sponsors of this episode:

✅ Genova Connect – Get 15% off any test kit with code METABOLICLINK here.

✅ Toups and Co – Get 15% off your first order with code METABOLIC here.

✅ Troscriptions – Get 10% off your first order with code METABOLICLINK here.

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In every episode of The Metabolic Link, we'll uncover the very latest research on metabolic health and therapy. If you like this episode, please share it, subscribe, follow, and leave us a comment or review on whichever platform you use to tune in!

You can find us on all your major podcast players here and full episodes are also up on our Metabolic Health Summit YouTube channel!

Find us on social:

• Instagram
• Facebook
• YouTube
• LinkedIn

Please keep in mind: The Metabolic Link does not provide medical or health advice, but rather general information that does not serve as a substitute for a licensed healthcare professional. Never delay in seeking medical advice from an appropriately licensed medical provider for any health condition that you may have.

The term “ultra-processed food” appeared nearly 100 times in the White House’s Make America Healthy Again report. But questions remain about whether the concept is precise enough to guide effective policy.

Dr. David Ludwig—Harvard endocrinologist, obesity researcher, and author of Always Hungry—joins Dr. Dominic D'Agostino to dismantle the ultra-processed food framework from the inside out. Ludwig reveals why the NOVA classification system lumps protein bars with soda, why the FDA admitted they can't define what they're trying to regulate, and why the famous studies showing ultra-processed foods cause overeating may be fundamentally flawed.

This conversation cuts through the noise to identify what actually matters: the mechanistic difference between processing carbohydrates, fats, and proteins—and why that distinction should reshape nutrition policy.

Questions answered in this episode:

• Can ultra-processed foods be "fixed" through reformulation?
• What's the most overrated "healthy" food in supermarkets?
• Should omega-3 levels be part of standard blood work?
• Are GLP-1 drugs a metabolic reset or a lifelong crutch?
• If you could pass one food policy law, what would it be?
• Why did the low-fat diet era make obesity worse?

Dr. Ludwig argues that "ultra-processed food" is a compelling marketing term without mechanistic grounding—and that precise, actionable targets like highly processed carbohydrates and demonstrably harmful additives would do far more to improve public health.

Where to find more of Dr. Ludwig's work online:

• Blog on UPF
• NEJM paper on UPF
• Problems with short diet trials
• Carbohydrate-insulin model
• Website

Special thanks to the sponsors of this episode:

✅ Fatty15 – Get 15% off a 90-day Starter Kit with code METABOLICLINK here.
✅ Troscriptions – Get 10% off your first order with code METABOLICLINK here.
✅ iRestore - Get a huge discount on the iRestore Illumina Face Mask when you use the code METABOLICLINK here.
✅Genova Connect – Get 15% off any test kit with code METABOLICLINK here.

In every episode of The Metabolic Link, we'll uncover the very latest research on metabolic health and therapy. If you like this episode, please share it, subscribe, follow, and leave us a comment or review on whichever platform you use to tune in!

You can find us on all your major podcast players here and full episodes are also up on our Metabolic Health Summit YouTube channel!

Find us on social:

• Instagram
• Facebook
• YouTube
• LinkedIn

Please keep in mind: The Metabolic Link does not provide medical or health advice, but rather general information that does not serve as a substitute for a licensed healthcare professional. Never delay in seeking medical advice from an appropriately licensed medical provider for any health condition that you may have.