The Dr. Hyman Show

Histamine isn't just about seasonal allergies or a runny nose. It influences your brain, gut, hormones, immune system, and nervous system—and when your body can't regulate it properly, it can show up as everything from anxiety and migraines to insomnia, digestive issues, skin rashes, and brain fog. In this episode, I explain why histamine overload happens, how it relates to Mast Cell Activation Syndrome (MCAS), and what a root-cause approach looks like for calming an overactive immune system.

In today's episode, I discuss:

* Why MCAS and histamine intolerance are different—and how overactive mast cells can drive symptoms ranging from migraines and anxiety to digestive issues, hives, and heart palpitations
* The hidden triggers behind mast cell activation, including gut dysfunction, chronic infections, mold exposure, hormone imbalances, stress, and environmental toxins
* Why many "healthy" foods like avocados, spinach, tomatoes, kombucha, and bone broth can temporarily worsen symptoms when your histamine bucket is already full
* A root-cause approach to calming the immune system using nutrition, targeted supplements, medications when needed, nervous system regulation, and addressing the underlying drivers of inflammation

MCAS isn't simply a histamine problem—it's a sign that your immune system has become dysregulated. Instead of just suppressing symptoms, the goal is to understand why your mast cells are overreacting in the first place. When you lower the overall inflammatory load and restore balance to the gut, immune system, hormones, and nervous system, you create the conditions for lasting healing rather than temporary symptom relief.

Resources Mentioned:

* Track your biomarkers with Function Health: https://functionhealth.com/mark (Use code MARK2026 for $50 off your membership.)
* Have a question you’d love answered on Office Hours? Submit it here

For decades, we've thought about conditions like Alzheimer's disease, depression, and Parkinson's disease as disorders of the brain. But what if that's only part of the story?

Emerging science is revealing that many of the factors driving cognitive decline, mental illness, and neurodegenerative disease may begin far outside the brain itself—in our metabolism, our immune system, our gut microbiome, our hormones, and even the environment we're exposed to every day.

As part of our summer series, we're revisiting some of the most important conversations we've had on the topic of brain health.

In this special compilation episode, you'll hear from leading experts Dr. Richard Isaacson, Dr. Chris Palmer, and Drs. Ray Dorsey and Michael Okun as they explore the new science of brain health and what it means for preventing cognitive decline, supporting mental health, and protecting our brains as we age.

What I find most encouraging about this research is that it challenges the idea that brain decline is simply an inevitable part of aging. Instead, it suggests that many of the biggest drivers of brain health are things we can influence through the choices we make, the environments we create, and the ways we care for our bodies long before symptoms ever appear.

View Show Notes From This Episode

Sign up for Dr. Hyman’s Brainshaping Academy to learn how to nourish the biological systems that support your mental, emotional, and cognitive health

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(0:00) Understanding brain dysfunction, inflammation, and lifestyle interventions

(0:21) Heavy metals, toxins, and Parkinson's disease

(3:30) Introduction to the summer series on brain health

(4:02) The MIND diet, precision nutrition, and brain-healthy fats

(9:06) Vitamins, supplements, and caloric intake for cognitive health

(11:23) Vitamin D, B complex, and reversing mild cognitive impairment

(14:05) Additional supplements and intensive lifestyle interventions

(17:18) Importance of magnesium and metabolic health

(18:24) Multimodal treatments, hormone replacement therapy, and individualized care

(26:49) Biopsychosocial factors, stress, and the gut-brain connection

(32:30) Inflammation, energy dysregulation, and metabolism in brain health

(42:33) Parkinson's disease: causes, history, and environmental factors

(46:02) Leaky brain, blood-brain barrier, and Parkinson's as a whole-body disease

(49:00) Closing remarks, disclaimer, and gratitude to sponsors

You've cleaned up your diet. You're taking the supplements. You're exercising, sleeping more, and doing everything "right." So why do you still feel exhausted, inflamed, anxious, or stuck? In this encore episode—one of the most impactful Office Hours conversations we've shared—I explore a question that could change the way you think about healing: What if your nervous system is the missing piece? When your body doesn't feel safe, it prioritizes survival over repair, affecting everything from your metabolism and hormones to your gut, immune system, and brain.

In today's episode, I break down:

Why chronic stress changes your biology—and how nervous system dysregulation can drive inflammation, hormone imbalance, digestive issues, weight gain, and autoimmune disease

The difference between living in constant "fight-or-flight" versus a regulated nervous system that supports healing, resilience, and recovery

Simple, science-backed strategies to regulate your nervous system, including breathwork, blood sugar balance, strength training, sleep, and daily safety cues

Why you can't out-supplement or out-biohack chronic stress—and how creating physiological safety unlocks your body's natural ability to heal

Healing isn't just about finding the right supplement or following the perfect diet. It's about creating an environment where your body feels safe enough to repair itself. When you begin working with your nervous system instead of against it, everything else—from your energy and metabolism to your mood and resilience—can start to change.

Check out my full conversation with Dr. Scott Sherr HERE.
Track your health with Function Health: https://functionhealth.com/mark (Use code MARK2026 for $50 off your membership.)

Have a question you’d love answered on Office Hours? Submit it here

Resources Mentioned:

Listen to my full conversation with Dr. Scott Sherr on nervous system regulation and mitochondrial health.

As part of our summer series, we're revisiting some of the most important conversations we've had on the topics that matter most to our health. And few are more important than heart disease.

Heart disease remains the number one cause of death worldwide. Yet despite decades of research, millions of prescriptions, and billions of dollars spent on treatment, many people are still confused about what actually causes it—and what we can do to prevent it.

For years, the conversation around heart disease has focused almost entirely on cholesterol. But what if that's only part of the story?

In this special compilation episode, you'll hear from Dr. Cindy Geyer of The UltraWellness Center, Dr. Eric Topol, and Dr. Aseem Malhotra as they explore a different perspective on heart disease—one that goes beyond cholesterol and looks at the deeper drivers of cardiovascular risk, including inflammation, insulin resistance, metabolic dysfunction, lifestyle, and early detection.

You'll hear why many experts now believe heart disease often begins decades before symptoms appear, why traditional testing can miss important warning signs, and how emerging science is giving us new tools to identify risk earlier than ever before.

Most importantly, you'll hear a message that is both practical and hopeful: that many of the factors driving heart disease are within our control, and that prevention remains one of the most powerful tools we have.

Let's dive in.

View Show Notes From This Episode

Sign up for Dr. Hyman’s Brainshaping Academy to learn how to nourish the biological systems that support your mental, emotional, and cognitive health

https://drhyman.com/products/brainshaping?utm_source=dr_hyman_show&utm_medium=newsletter&utm_campaign=may_27&utm_content=link

Get Free Weekly Health Tips from Dr. Hyman

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Sign Up for Dr. Hyman’s Weekly Longevity Journal

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Join the 10-Day Detox to Reset Your Health

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Join the Hyman Hive for Expert Support and Real Results

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This episode is brought to you by BON CHARGE, BIOptimizers, Rho, Made In, Seatopia, and Cozy Earth.

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(0:00) The persistence of heart disease and the low-fat diet hypothesis

(0:32) Preventing heart disease through diet, lifestyle, and simple behaviors

(2:19) Revisiting key conversations on heart disease

(3:44) Beyond cholesterol: deeper drivers and risk factors

(7:18) Typical workup, treatments, and advances in cholesterol testing

(17:48) Metabolic health, hormonal, and inflammatory factors in heart disease

(29:37) Advances in cardiovascular diagnostics and AI

(31:31) Impact of lifestyle and new pharmacological treatments

(36:55) Statins, side effects, and lipoprotein fractionation

(40:13) The role of AI, new diagnostics, and Dr. Topol's journey

(43:19) Rethinking treatment: diet, industry influence, and the low-fat craze

(45:28) Saturated fat, cholesterol, and revisiting the evidence

(48:00) Cholesterol in heart disease risk and systematic drug review

(52:31) Insulin resistance, cholesterol’s role, and mortality

(58:31) Challenges in changing medical dogma

(1:00:31) Closing remarks and call to action

High cholesterol has been treated as the main cause of heart disease for decades. But over the years, I've changed my mind. Today, I believe cholesterol is only part of the story, and that inflammation, insulin resistance, and metabolic health are often the real drivers of cardiovascular disease. In this encore episode, I'm revisiting one of my most talked-about Office Hours conversations to share how my thinking has evolved and why understanding the root cause of heart disease can completely change the way you approach prevention.

In today's episode, I discuss:

Why cholesterol alone is a poor predictor of heart disease—and the biomarkers I believe matter even more, including ApoB, lipoprotein(a), inflammation, and insulin resistance

The surprising role sugar, refined carbohydrates, and metabolic dysfunction play in driving cardiovascular disease

Why two people with the same cholesterol can have dramatically different heart disease risk—and how a personalized approach changes the conversation

The nutrition, lifestyle, and testing strategies I use to help reduce inflammation, improve metabolic health, and lower cardiovascular risk at its source

Heart disease isn't simply a cholesterol problem—it's often a metabolic and inflammatory problem. When you understand what's really driving your risk, you can stop chasing a single number and start addressing the underlying biology that supports lifelong cardiovascular health.

Track your metabolic and cardiovascular health biomarkers: functionhealth.com/mark for 160+ lab tests at just $365/year. Use code MARK2026 for $50 off.

Have a question you'd love answered on Office Hours? Submit it here'

(0:00) The cholesterol and heart disease paradox; introduction and overview of cholesterol, inflammation, and metabolic health

(1:11) Sponsor: Function Health

(1:41) Traditional views vs. new science on cholesterol, inflammation, and heart disease

(4:52) Inflammation and sugar as key factors in heart disease

(8:41) Advanced markers: ApoB, lipoprotein fractionation, and comprehensive testing

(13:57) Causes of inflammation and holistic heart disease prevention

(19:35) Metabolic health risks, new technologies, and personalized interventions

(22:35) Diet, exercise, lifestyle, and supplements for heart and metabolic health

(25:03) Understanding heart disease beyond cholesterol

(25:37) Sponsor: Brain Shaping Academy

(26:33) Community engagement, sharing, and final thoughts

(28:07) Sponsor acknowledgments and closing remarks