July 26, 2021 • 1hr 49min

How to Optimize Your Brain-Body Function & Health

Huberman Lab

In this episode, Dr. Andrew Huberman explores interoception - our sense of our internal bodily state. He explains how the brain and body communicate via mechanical and chemical signals, and how this impacts our health, performance, and wellbeing. The discussion covers key aspects of brain-body communication including breathing, heart rate, gut health, fever, nausea, and emotions. Huberman provides science-based protocols to leverage interoception for improved mental and physical function.

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Key Takeaways

Interoception is our sense of our internal bodily state and is crucial for health, performance, and wellbeing
The brain-body connection relies on mechanical and chemical signals from our organs to inform the brain about our internal state
The vagus nerve is the main communication pathway between brain and body organs
Breathing patterns can be used to quickly shift mental/physiological states by altering heart rate and nervous system activation
Gut health and microbiome diversity are key for proper brain-body communication and overall health
Fermented foods are more effective than high-fiber diets for improving gut microbiome diversity and reducing inflammation
Interoceptive awareness can be improved through practices like meditation and heartbeat sensing exercises
Understanding interoception provides powerful tools to modulate mood, focus, stress, and healing

Introduction

In this episode, Dr. Andrew Huberman explores interoception - our sense of our internal bodily state. He explains how the brain and body communicate via mechanical and chemical signals, and how this impacts our health, performance, and wellbeing. The discussion covers key aspects of brain-body communication including breathing, heart rate, gut health, fever, nausea, and emotions. Huberman provides science-based protocols to leverage interoception for improved mental and physical function.

Topics Discussed

Mechanical and Chemical Signaling (8:22)

Huberman explains that brain-body communication relies on two key types of signals:

Mechanical signals - information about pressure, volume, and movement of organs
Chemical signals - information about the chemical composition and state of organs/blood

These signals are transmitted primarily via the vagus nerve to inform the brain about our internal state. The brain then sends signals back to regulate organ function.

Lung-Diaphragm-Brain (LDB) Dialogue (17:50)

Huberman details how breathing mechanics impact brain function:

Inhaling expands the lungs and lowers the diaphragm, increasing heart volume and slowing blood flow
This triggers the brain to speed up heart rate on inhale
Exhaling does the opposite - raising diaphragm, decreasing heart volume, speeding blood flow
This causes the brain to slow heart rate on exhale

Understanding this mechanism allows us to use breathing to quickly shift mental/physiological states.

Breathing Protocols for Alertness and Calm (21:00)

Huberman provides three breathing protocols to leverage the LDB dialogue:

Physiological sigh - Double inhale through nose followed by long exhale through mouth. Calms the system quickly.
Alertness breath - Forceful inhales with short exhales. Increases alertness and adrenaline.
Box breathing - Equal inhale, hold, exhale, hold. Balances the system.

Carbon Dioxide and Oxygen Balance (30:54)

Huberman explains how CO2 levels in the blood trigger breathing:

Neurons in the brain stem detect when CO2 levels rise above a threshold
This triggers the impulse to breathe to bring in more oxygen
We don't breathe for oxygen, but to eliminate excess CO2

Understanding this allows for practices like the Wim Hof method to alter CO2/O2 balance and mental state.

Gut-Brain Communication (42:47)

The gut communicates with the brain via:

Mechanical signals about fullness/emptiness
Chemical signals about nutrient content and gut microbiome

This informs the brain about hunger, digestion, and overall health state. Improving gut health enhances this communication.

Enhancing Gut-Brain Communication (48:18)

Huberman recommends fasting to improve gut-brain signaling:

Intermittent fasting (12-16 hour daily fasts) improves gut health
Fasting stimulates autophagy - clearing of dead/senescent cells
Improves interoceptive awareness of hunger/fullness signals

Nutrients and Gut Signaling (51:50)

Certain nutrients trigger increased gut-brain signaling:

Omega-3 fatty acids
Amino acids
Sugars

This explains why we crave certain foods. Understanding this allows us to hack the system to reduce cravings.

Reducing Sugar Cravings (57:00)

Huberman recommends consuming glutamine and healthy fats to reduce sugar cravings:

1 tsp glutamine in full-fat cream
Triggers same gut-brain signals as sugar
Satisfies craving without negative effects of sugar

Gut Acidity and Microbiome (58:58)

Proper gut acidity is crucial for microbiome health:

Stomach needs to be more acidic than other tissues
Acidity prevents harmful bacteria growth
Proper acidity allows beneficial bacteria to thrive

Improving Gut Health (1:04:13)

Huberman discusses new research on improving gut health:

Fermented foods are more effective than fiber for improving microbiome diversity
2-4 servings of fermented foods daily reduces inflammatory markers
Examples: sauerkraut, kimchi, yogurt, kefir

Leaky Gut and Autoimmune Issues (1:13:10)

Huberman explains how poor gut health leads to autoimmune issues:

"Leaky gut" occurs when gut lining becomes permeable
Allows food particles to enter bloodstream
Triggers immune response and inflammation
Can be improved by addressing gut health

Nausea and the Brain (1:21:45)

Nausea is triggered by neurons in the brain stem that detect blood toxins:

Area postrema senses blood chemistry
Triggers vomiting reflex if toxins detected
Can be activated by memories/thoughts in some people

Reducing Nausea (1:28:25)

Huberman provides evidence-based ways to reduce nausea:

Ginger (1-3g)
Peppermint
CBD

Fever and Temperature Regulation (1:30:40)

Fever is triggered by neurons detecting toxins in cerebrospinal fluid:

OVLT neurons sense toxins/pathogens
Signal brain to increase body temperature
"Cooks" pathogens to kill them

Cooling the Body Properly (1:37:00)

To reduce dangerous fever, cool these areas:

Bottoms of feet
Palms of hands
Upper face

Do not cool neck/torso only as this can increase core temperature.

Emotions and Interoception (1:38:53)

Emotions arise from interoceptive signals:

Vagus nerve aggregates signals from gut, heart, lungs
Informs brain of overall bodily state
Brain interprets this as emotions

Our facial expressions reflect this internal state.

Sensing Others' Emotions (1:45:00)

We can unconsciously sense others' internal states:

Heart rate and breathing synchronize with others
Allows empathy and emotional attunement
Not through "mirror neurons" (which are largely a myth)

Improving Interoception (1:46:00)

Huberman recommends this exercise to improve interoceptive awareness:

Try to sense/count your heartbeats for 1-2 minutes
Can be done during meditation or breath work
Quickly improves vagal tone and interoceptive ability

Conclusion

Understanding interoception - our sense of our internal bodily state - provides powerful tools to modulate our mental and physical function. By leveraging breathing patterns, improving gut health, and enhancing our interoceptive awareness, we can better regulate our mood, focus, stress levels, and overall wellbeing. Simple practices like breathing exercises, consuming fermented foods, and heartbeat sensing can yield significant improvements in brain-body communication and health.