June 21, 2021 • 1hr 55min

How Smell, Taste & Pheromone-Like Chemicals Control You

Huberman Lab

In this episode, Dr. Andrew Huberman explores how humans sense chemicals through smell, taste, and pheromone-like effects. He explains the neurobiology behind these senses, their connections to brain function and health, and how they influence our behavior, emotions, and interactions with others. The discussion covers the latest scientific research on olfaction, gustation, and chemical signaling between humans, as well as practical ways to enhance these senses.

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Key Takeaways

Sniffing and nasal breathing enhance cognitive function and learning - The act of inhaling through the nose increases brain arousal and alertness, improving focus and memory formation
Smell and taste abilities reflect brain health - Loss of smell/taste can indicate neurological issues, while enhancing these senses may promote brain plasticity and regeneration
Humans communicate via chemical signals - We unconsciously detect and respond to chemicals in others' tears, sweat, and breath, influencing mood, hormones and behavior
Food cravings are shaped by what we eat - Eating more meat enhances umami taste receptors and cravings, while plant-based diets increase sensitivity to sweet tastes
Taste receptors exist beyond the tongue - Sweet and savory taste receptors are also found in the digestive tract and reproductive organs, potentially linking food and sensuality
Our sense of smell and taste is highly trainable - Simple practices like focused sniffing can significantly enhance our ability to detect and distinguish odors and flavors

Introduction

In this episode, Dr. Andrew Huberman explores how humans sense chemicals through smell, taste, and pheromone-like effects. He explains the neurobiology behind these senses, their connections to brain function and health, and how they influence our behavior, emotions, and interactions with others. The discussion covers the latest scientific research on olfaction, gustation, and chemical signaling between humans, as well as practical ways to enhance these senses.

Topics Discussed

The Neurobiology of Smell (20:03)

Huberman explains the basic anatomy and function of the olfactory system:

Odor molecules enter the nose and bind to receptors on olfactory neurons
Olfactory neurons send signals to the olfactory bulb and then to other brain regions
There are three main olfactory pathways in the brain:
- Innate responses (e.g. detecting smoke)
- Learned associations (e.g. memories linked to smells)
- Accessory olfactory system (possibly involved in pheromone effects)

"Olfaction is the most ancient sense that we have. Or I should say chemical sensing is among the most primitive and ancient senses that we have."

How Sniffing Enhances Brain Function (28:03)

Huberman discusses research showing that the act of inhaling through the nose has powerful effects on cognition:

Inhaling increases overall brain arousal and alertness
Nasal breathing improves memory formation and recall
Sniffing practice can enhance odor detection abilities

"The act of inhaling itself wakes up the brain. It's not about what you're perceiving or what you're smelling."

The Taste System and Its Functions (1:04:09)

The five basic tastes and their evolutionary purposes are explained:

Sweet - Detecting energy/sugar sources
Salty - Maintaining electrolyte balance
Bitter - Avoiding potential toxins
Sour - Detecting spoiled/fermented foods
Umami - Identifying protein/amino acid sources

A potential sixth basic taste for detecting fat is also discussed.

How Diet Shapes Food Preferences (1:24:13)

Huberman explains how our food choices can alter our taste receptors and cravings:

Eating more meat enhances umami taste receptors and increases cravings for savory foods
Plant-based diets increase sensitivity to and desire for sweet tastes
This may help explain differences in food preferences between various diets

"The more meat you eat, the more you're going to become like a tiger, so to speak. And the more that you avoid the umami flavors and meats...the more you will likely suppress that umami system and that you will have a heightened desire for appetite for and sensing of sweet foods."

Taste Receptors Beyond the Tongue (1:28:13)

An intriguing discovery about taste receptors is discussed:

Sweet and umami taste receptors are also found in the digestive tract and reproductive organs
This may create connections between food, digestion, and sensuality
It could explain why certain foods evoke strong emotional/physical responses

"What this means is that chemical sensing of the very things that we detect on our tongue and that we call taste, in quotes, in food, is also evoking cellular responses within the reproductive gonads."

Chemical Signaling Between Humans (1:40:18)

Huberman reviews evidence for chemical communication between humans:

Women's tears reduce testosterone and sexual arousal in men
Chemical signals from women can alter other women's menstrual cycles
People can identify their partner's scent from a t-shirt at very low concentrations
We unconsciously smell our hands after shaking hands with new people

"Clearly it does. Actually. You and every other human, from the time you're born until the time you die, are actively seeking out and sensing and evaluating the chemicals that come from other individuals."

Enhancing Smell and Taste Abilities (1:52:19)

Practical ways to improve olfactory and gustatory senses are provided:

Practice focused sniffing to increase odor sensitivity
Pay close attention to food flavors to develop a more nuanced palate
Use "miracle fruit" to temporarily alter taste perceptions as an experiment
Regular exercise and social interactions may boost olfactory neuron regeneration

"You can actually have a heightened experience of something. And that, of course, will also be true for the taste system."

Smell, Taste and Brain Health (42:06)

The connections between chemical senses and neurological health are explored:

Loss of smell can be an early sign of neurodegenerative diseases
Olfactory abilities may indicate recovery from traumatic brain injury
Enhancing smell/taste could potentially promote brain plasticity and regeneration

"How well we can smell and taste things is actually a very strong indication of our brain health."

Conclusion

This episode provides a comprehensive overview of how humans sense and respond to chemicals in our environment through smell, taste, and pheromone-like effects. Dr. Huberman explains the neurobiology behind these senses and their deep connections to brain function, health, and behavior. The discussion reveals how these ancient chemical sensing systems continue to play vital roles in our modern lives - influencing everything from our food choices to our social interactions.

Importantly, the episode also offers practical ways for listeners to enhance their smell and taste abilities, potentially benefiting overall brain health and sensory experiences. By understanding and harnessing the power of these chemical senses, we can gain new insights into our own biology and the subtle chemical communication constantly occurring between humans.