March 15, 2021 • 1hr 40min

How Foods and Nutrients Control Our Moods

Huberman Lab

In this episode, Dr. Andrew Huberman explores the intricate connections between the brain, body, and gut that allow the foods we eat to influence our moods, emotions, and motivation. He discusses key pathways like the vagus nerve, the role of neurotransmitters like dopamine and serotonin, and how the gut microbiome impacts our mental states. The episode covers many actionable tools related to diet, supplements, fasting, and probiotics that can be used to positively influence mood and mental health through nutrition.

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Key Takeaways

The vagus nerve is a key pathway connecting the brain and body, sending sensory information from organs to the brain and motor signals from the brain back to organs
Nutrients and foods we ingest can significantly impact our mood and emotions by influencing neurotransmitters like dopamine and serotonin
The gut microbiome plays an important role in the gut-brain axis, but its effects are highly individual - what works for one person may not work for another
Omega-3 fatty acids, particularly EPA, can have antidepressant effects comparable to some medications when taken at doses around 1000mg per day
Our beliefs and mindset about foods can impact how our body physiologically responds to them, highlighting the power of top-down cognitive effects
Fermented foods, probiotics, and a healthy gut microbiome can support mood and mental health, but excessive probiotic supplementation may cause issues like brain fog
Artificial sweeteners like saccharin can disrupt the gut microbiome, but effects vary between different sweeteners
Fasting can deplete the gut microbiome, which may contribute to some of the challenges when returning to eating
Processed foods tend to have negative health impacts regardless of whether they come from animal or plant sources

Introduction

In this episode, Dr. Andrew Huberman explores the intricate connections between the brain, body, and gut that allow the foods we eat to influence our moods, emotions, and motivation. He discusses key pathways like the vagus nerve, the role of neurotransmitters like dopamine and serotonin, and how the gut microbiome impacts our mental states. The episode covers many actionable tools related to diet, supplements, fasting, and probiotics that can be used to positively influence mood and mental health through nutrition.

Topics Discussed

The Vagus Nerve and Brain-Body Connection (12:30)

The vagus nerve is a key pathway connecting the brain and body:

It sends sensory information from organs like the gut, heart, and lungs to the brain
It carries motor signals from the brain back to organs to control things like digestion and heart rate
It allows the gut to communicate nutrient information to the brain, influencing mood and behavior

Dr. Huberman cautions against oversimplified ideas of "stimulating the vagus nerve," as its effects are complex and context-dependent. He notes that the popular "polyvagal theory" is not fully supported by modern anatomy.

Sugar Sensing and Reward Pathways (19:35)

The gut can sense sugar content independently of taste:

Neurons in the stomach detect sugar and signal the brain to release dopamine, creating cravings
This happens even if we can't consciously taste the sugar
This explains why "hidden sugars" in savory foods can still drive cravings and overeating

Dr. Huberman explains: "You actually have sensors within your body that make you crave sugar independent of the sweet taste of those things."

Dopamine, Motivation, and L-Tyrosine (32:01)

Dopamine is crucial for motivation, mood, and movement:

It is synthesized from the amino acid L-tyrosine, found in foods or supplements
Increasing L-tyrosine intake can boost dopamine levels and potentially improve mood
However, excessive supplementation can lead to crashes or disrupted dopamine pathways

Dr. Huberman notes: "L-tyrosine, however, can be ingested through foods or through supplementation to increase dopamine levels. That's well known."

Serotonin and the Gut-Brain Axis (38:29)

Serotonin plays a key role in mood and satiety:

While most serotonin is produced in the gut, the serotonin affecting mood is primarily in the brain
Carbohydrate-rich foods can increase serotonin production
Some people supplement with 5-HTP to boost serotonin, but this can disrupt sleep patterns

Dr. Huberman suggests timing nutrient intake to support circadian rhythms: "I usually fast and exercise in the early part of the day. I eat a relatively high protein and moderate fat, zero carb or low carb meal at lunch and in the afternoon to stay alert...As evening comes around...I will ingest foods that promote serotonin release."

Omega-3 Fatty Acids and Depression (56:45)

Omega-3 fatty acids, particularly EPA, can have significant antidepressant effects:

Studies show 1000mg of EPA daily can be as effective as some antidepressants
It works in part by improving heart rate variability
Fish oil supplements are a common source, but quality and potential side effects should be considered

Dr. Huberman shares: "I started taking 1000 milligrams per day of EPA in fish oil. Now there are a few side effects of fish oil...But I just felt better. I wasn't clinically depressed, but I did feel, at least for me, an increase in mood and affect."

L-Carnitine and Mood (1:09:05)

L-carnitine shows promise for improving mood and other health factors:

It can cross the blood-brain barrier and impact neurotransmitter function
Studies show potential benefits for depression, autism symptoms, and migraine
It may also improve fertility and sperm quality

Dr. Huberman notes the wide-ranging effects: "L-carnitine has been shown to reduce symptoms of fibromyalgia...It had a significant effect on reducing the number of migraine attacks per month."

The Gut Microbiome and Mental Health (1:16:29)

The gut microbiome plays a crucial role in the gut-brain axis:

A healthy microbiome supports mood, digestion, and immune function
Fermented foods are one of the best ways to support gut health
Probiotic supplements can be helpful, but excessive use may cause brain fog
The ideal diet for gut health varies significantly between individuals

Dr. Huberman emphasizes individual variation: "Some people's microbiome and the lining of their mucosa...is improved by diets that are heavily meat based and don't have many plants. Other people do much better on a plant based diet without many meat products or animal products. It's highly individual."

Artificial Sweeteners and Gut Health (1:25:20)

The effects of artificial sweeteners on gut health are complex:

Saccharin has been shown to disrupt the gut microbiome in negative ways
However, this doesn't necessarily apply to all artificial sweeteners
Sweeteners like stevia and monk fruit may have different effects

Dr. Huberman clarifies a common misconception: "It's not just that, a language thing where people say, oh, you know, it kills the microbiome. It doesn't kill the microbiome. It shifts the microbiome."

Fasting and the Microbiome (1:33:20)

Fasting can have significant effects on the gut microbiome:

Extended fasts can deplete the gut microbiome
This depletion may contribute to digestive challenges when returning to eating
The microbiome often replenishes to higher levels after a fast

Dr. Huberman explains: "The longer periods of fasting that go for a day or two or three days are known to deplete the gut microbiome in major ways. But that's not always necessarily a bad thing, because when it's replenished, it often is replenished at levels that exceeded its previous level."

Mindset Effects on Physiology (1:35:20)

Our beliefs about food can impact how our body responds physiologically:

Studies show that beliefs about calorie content can influence hormonal responses to identical meals
Mindset about daily activities can impact physiological measures like blood pressure and body fat
These effects go beyond simple placebo responses and highlight the power of top-down cognitive influences

Dr. Huberman shares a striking example: "People's belief about the content of something impacted their physiology...This speaks to these so called top down mechanisms or modulation of our physiology."

Conclusion

This episode highlights the intricate connections between our diet, gut health, and mental well-being. Dr. Huberman emphasizes that while there are general principles that apply broadly, the optimal approach for supporting mood and mental health through nutrition is highly individual. He encourages listeners to experiment thoughtfully with different dietary approaches, considering factors like fermented foods, omega-3 intake, and probiotic use. The episode also underscores the powerful influence our mindset and beliefs can have on how our body responds to food, highlighting the complex interplay between mind and body in determining our overall health and well-being.