How Smell, Taste & Pheromone-Like Chemicals Control You
Andrew Huberman explores how our senses of smell, taste, and human-emitted chemicals profoundly influence our feelings, actions, and hormones. He provides tools like nasal breathing and sniffing exercises to enhance cognition and sensory perception, and delves into the biological underpinnings of taste and food cravings.
Deep Dive Analysis
21 Topic Outline
Introduction to Chemical Sensing: Smell, Taste, and Pheromones
Brief Vision Protocols Recap and Correction
Chemicals from Tears Affect Other People's Hormones
Smell System: Sniffing, Brain Connection, and Innate/Learned Responses
Pheromone Effects in Animals: Miscarriage and Puberty Timing
Sniffing Enhances Alertness, Focus, and Learning
Smelling Salts and Ammonia: Extreme Arousal
Training Your Sense of Smell and Taste
Smell as a Readout of Brain Health and Neurogenesis
Dopamine, New Relationships, and Olfactory Neurogenesis
Brain Injury and Loss of Smell: Recovery Insights
Mint Scents and Arousal Pathways
Genetic Differences in Odor Perception: Popcorn, Cilantro, Skunk
The Five (and Sixth) Senses of Taste and Their Functions
The Mouth as an Extension of the Gut: Taste Receptors Beyond the Tongue
Taste Receptors on Gonads: Sensuality of Sweet and Umami
Maillard Reaction: Sugar-Amino Acid Interaction and Savory Taste
How Processed Foods Drive Cravings and Dopamine
Pheromones and Mating: The Coolidge Effect in Males and Females
Chemical Signaling Between Women and Menstrual Cycles
Subconscious Chemical Exchange: Handshakes and Bunting Behavior
8 Key Concepts
Olfactory Bulb
A collection of neurons at the base of the brain that extends into the nose's mucosal lining. These neurons detect odorant compounds and send signals to different brain regions for innate, learned, and potentially pheromonal responses.
Anosmic
A condition where an individual has lost their sense of smell. This often results in a diminished sense of taste as well, highlighting the close connection between the two chemical senses.
Neurogenesis (Olfactory)
The continuous birth and replenishment of new olfactory neurons throughout life. These neurons originate in the subventricular zone of the brain and migrate to the olfactory bulb, making the smell system unique in its regenerative capacity.
Gustatory Nerve
A collection of nerve bundles that transmit taste information from the tongue to the brain. This nerve relays signals from taste receptors on the tongue to the nucleus of the solitary tract, thalamus, and insular cortex for taste perception.
Umami Taste
One of the five basic tastes, detected by specific receptors on the tongue. It signals the presence of amino acids, which are essential for survival, and is often described as a savory or meaty flavor.
Maillard Reaction
A non-enzymatic browning reaction in cooking that occurs between sugars and amino acids under heat. This reaction creates savory, umami-like flavors and produces ketone groups, which contribute to the aroma and taste of cooked foods.
Coolidge Effect
A phenomenon observed in many animal species where a male (or female) that has reached sexual exhaustion with one partner will spontaneously regain the ability and desire to mate if a new partner is introduced. This effect can be triggered purely by the odor of the new individual.
Bunting Behavior
A phenomenon observed in animals, such as dogs and cats, where they rub their heads or bodies against others. This behavior involves rubbing scent glands to mark territory or individuals, and humans exhibit similar subconscious actions like touching eyes after a handshake.
9 Questions Answered
Chemicals released by other humans, such as those in tears, sweat, or even breath, can profoundly modulate our internal state, including hormone levels and brain activity, often subconsciously.
Sniffing, or inhaling through the nose, increases brain arousal and alertness, enhancing focus, attention, and the ability to learn and remember information, even for non-olfactory tasks.
Yes, humans can significantly enhance their sense of smell and taste through practice, such as repeated sniffing (even of nothing) or actively paying attention to the nuances of odors and flavors, leading to long-term sensitivity increases.
Loss of smell can be an early indicator of brain health issues like dementia or Parkinson's, and it's a common symptom of traumatic brain injury. Regaining smell can also be a readout of recovery from head injuries.
The five basic tastes are sweet (signals energy/sugars), salty (signals electrolytes), bitter (signals poisons), umami (signals amino acids), and sour (signals spoiled or fermented food), each guiding us toward beneficial or away from harmful substances.
Emerging data suggest the existence of a sixth taste receptor on the tongue that senses fat, indicating its critical role in our diet and nervous system function.
Processed foods are engineered to activate dopamine release, not just through taste but also by triggering neurons in the gut, which creates a desire to seek and consume more of those foods, independent of their nutritional value or conscious enjoyment.
While the original synchronization theory is debated, recent data suggest that chemical signaling between women can indeed impact the timing of menstrual cycles, either shortening or lengthening them depending on the phase of the cycle of the emitting individual.
Humans subconsciously evaluate chemicals from others through actions like touching their eyes after a handshake, effectively transferring and sensing molecules from another person's skin, similar to how animals engage in bunting behavior.
10 Actionable Insights
1. Prioritize Nasal Breathing for Cognition
Practice nasal breathing during focused work, listening, or learning to increase alertness, attention, focus, and ability to remember information. The act of inhaling through the nose itself wakes up the brain and enhances learning.
2. Enhance Smell & Taste Sensitivity
To improve your sense of smell and taste, perform 10-15 nasal inhales (sniffs) followed by exhales, then smell an object like an orange or food. This practice increases brain alertness and olfactory neuron sensitivity, leading to richer perception and long-term discrimination ability.
3. Implement Near-Far Vision Exercises
Perform near-far viewing exercises for about five minutes, three times a week, to exercise the accommodation reflex and help offset myopia (nearsightedness). Bring an object close to your eyes, then look far into the distance, and repeat.
4. Spend Two Hours Daily Outdoors
Spend two hours outside daily, even while doing other activities like gardening or walking, to help offset myopia and nearsightedness. Sunlight and blue light from the sun benefit your visual system and brain.
5. Maintain Optimal Hydration & Electrolytes
Ensure proper hydration and adequate electrolyte intake (sodium, magnesium, potassium) for optimal brain and body function, preventing diminished cognitive and physical performance. Consider dissolving one packet of Element in 16-32 ounces of water first thing in the morning and during exercise.
6. Olfactory Training for TBI Recovery
If recovering from a traumatic brain injury (TBI), engage in active olfactory training by closely interacting with odors and focusing on inhales to wake up the brain and perceive nuances. This can stimulate new neuron creation and aid sensory performance recovery.
7. Actively Train Your Palate
Enhance your ability to taste and discern different components of foods by actively paying attention to what you are tasting. This practice can develop a more sensitive and nuanced palate over time.
8. Experiment with Miracle Berry
Ingest miracle berry (or miracle fruit) to temporarily alter taste perception, making sour foods taste sweet. This can help you understand the contribution of sweetness to various foods and explore taste perception.
9. Use Peppermint for Alertness
Inhale peppermint or other minty scents to increase attention and create an arousal response, which can heighten alertness. This effect is less intense than that of ammonia salts.
10. Consider Smelling Salts (Extreme Caution)
With extreme caution and professional guidance, ammonia inhalants (smelling salts) can trigger the brain’s arousal systems, leading to a ‘psyching up effect’ and increased maximal force in strength and power performance. Direct inhalation of ammonia can severely damage olfactory pathways and vision; use only with extreme care.
5 Key Quotes
What this means in kind of a literal sense is that you have neurons that extend their little dendrites and accidentally-like things, or little processes, as we call them, out into the mucus, and they respond to different odorant compounds.
Andrew Huberman
If you are somebody who doesn't have a very good sense of smell, or you're somebody who simply wants to get better at smelling and tasting things, you can actually practice sniffing.
Andrew Huberman
It is a total myth, complete fiction, that different parts of your tongue harbor different taste receptors.
Andrew Huberman
The taste system, and perhaps the smell system as well, can be trained so that you can learn to pick out the tones, if you will, of different ice cream or different beverages.
Andrew Huberman
Processed foods are really designed to take foods that ordinarily would spoil, that would have a shelf life, and extend their shelf life, to turn foods which are not a commodity into a commodity.
Andrew Huberman
4 Protocols
Enhancing Sense of Smell and Taste
Andrew Huberman- Perform 10-15 rapid inhales (sniffs) through the nose, followed by exhales.
- Immediately after, smell an object (e.g., an orange or food item).
- Note the heightened perception and richness of the odor compared to before the sniffing exercise.
Assessing Genetic Odor Sensitivity
Andrew Huberman- Smell microwave popcorn and determine if you find the scent pleasant, indifferent, or putrid (like vomit).
- Observe your reaction to cilantro or asparagus (specifically, the smell of urine after ingesting asparagus).
- Your individual response indicates the presence or absence of specific genes encoding olfactory receptors.
Becoming a Super-Taster by Top-Down Behavioral Plasticity
Andrew Huberman- Actively pay close attention to the different component parts and nuances of the foods and beverages you are ingesting.
- Consciously try to pick out specific 'tones' or flavors within complex tastes.
- Consistent practice of this focused attention can significantly enhance your palate and ability to discriminate tastes over time.
Inverting Sense of Sweet & Sour with Miracle Fruit
Andrew Huberman- Ingest a miracle berry or miracle fruit product (check product-specific instructions and warnings).
- Immediately after, bite into a lemon or other sour food (e.g., lemon peel).
- Observe how the sour food now tastes sweet, as if it were a peach, due to a temporary change in taste receptor configuration. This effect can last several hours.