How Foods and Nutrients Control Our Moods

Emotions and the Brain-​​Body Relationship

• Emotions arise from both the brain and the body
• No agreement on what is a good or bad emotion
• Emotions involve biological and chemical events within the body

Food and Nutrition’s Impact on Emotions

• Ingesting certain nutrients (macronutrients and micronutrients) can impact the chemicals in our brain that give rise to emotions
• Scientific studies have explored how the brain and body interact to support certain neurochemicals that give us feelings of happiness, sadness, alertness, etc.

Darwin’s Theory on Emotions

• Emotions are universal, and some facial expressions are universal
• Two most robust examples:
• Attraction: leaning in, inhaling air, bringing in more of the chemical substance
• Aversion: leaning back, looking away, cringing face, avoiding inhaling chemicals

Push-​​Pull of Attraction and Aversion

• Foundation of any discussion about emotion
• Works for many different circumstances and brain circuits
• Go circuits: emphasize action
• No-​​go circuits: deemphasize action and prevent action

• Aversion and attraction are push-​​pull emotions 
  • Attraction: delight, happiness, excitement
  • Aversion: disgust, avoidance
• Actions in the nervous system involve motor behaviors and muscle contractions
• Some attractions and aversions are innate or hardwired 
  • Bitter compounds associated with poisons, leading to aversion
  • Sweet or savory tastes lead to attraction

The Vagus Nerve

• Connects the brain and body, regulating emotional states
• Polyvagal theory by Stephen Porges 
  • Acknowledges the many branches of the vagus nerve
  • Dorsal vagus involved in alertness and activation
  • Ventral pathway involved in empathic behaviors
• Sensory information from organs sent to the brain 
  • Gut, heart, lungs, and immune system
• Motor information from the brain sent to the body
• Vagus nerve can be activated in specific ways to improve mood and well-being

Understanding the Vagus Nerve

• Sensory information from various organs sent to the brain 
  • Gut: fullness, acidity
  • Heart: heart rate
  • Lungs: lung capacity
  • Immune system: presence of bacteria or contaminants
• Motor information from the brain sent to the body
• Vagus nerve analyzes features within the body and informs the brain

Sugar and the Vagus Nerve

• Sweet foods generally taste good and are attractive
• Neurons in the stomach sense the presence of sugary foods independent of taste 
  • Sends information to the brain via the vagus nerve
  • Releases dopamine, creating a craving for more sugar
• Experiments show that people crave sugar even when they can’t taste it 
  • Due to sensors in the gut that detect sugar

• Gut feelings can be chemical gut feelings driven by specific neurons detecting features in the body
  Sugars, Food Cravings, and the Brain

• Attraction to certain foods comes from information sent to the brain from the body

• Hidden sugars in foods can cause cravings without knowing why
• Reframe the way we think about hidden sugars in foods

Anxiety and Alertness Around Food

• Anxiety associated with approaching food
• Continuum of alertness vs. calmness
• Lateral hypothalamus in the brain inhibits feeding
• Locus ceruleus releases norepinephrine, creating alertness
• Stress and anxiety around mealtime is normal

Digestion and Nutrient Sensing

• Digestion starts in the mouth
• Vagus nerve senses what’s in the gut and sends information to the brain
• People eat until the brain perceives adequate intake of amino acids

Amino Acids and Neurochemicals

• Amino acids are building blocks for muscle and neurochemicals in the brain
• Dopamine is a molecule that makes you feel good and is released within the brain
• Dopamine release is caused by surprise, excitement, and events that turn out well
• Reward prediction error: when expectations are not met, dopamine release is less

Dopamine and Desire

• Dopamine is the molecule of desire, wanting, and motivation
• Amino acid sensors in the gut detect how many and which amino acids are present
• L‑tyrosine is a precursor to dopamine and is found in various foods

• Misconception that most serotonin and dopamine are in the gut, affecting mood
  Dopamine and the Brain-​​Body Connection

• Dopamine neurons reside in the brain

• Some people make too little dopamine 
  • Parkinson’s patients need prescription dopamine (LDPA)
  • Parkinson’s is associated with deficits in movement, mood, and motivation 
    • Examples: Mohammed Ali, Michael J. Fox, Freddie Roach
• Dietary L‑tyrosine supports healthy production of dopamine 
  • Can be ingested through foods or supplementation
  • Overconsumption can lead to a crash and brain fog
  • People with preexisting hyperdopaminergic conditions should avoid L‑tyrosine
• Drugs that increase L‑tyrosine and dopamine can have addictive properties 
  • Examples: methamphetamine, cocaine

Dopaminergic Antidepressants

• Wellbutrin (generic name: bupropion) activates dopamine and epinephrine 
  • Involved in motivation, alertness, and effort
  • Side effects: anxiety, sweating, pupil dilation, effects on epilepsy patients
  • Used for smoking cessation

The Vagus Nerve and the Brain-​​Body Connection

• Vagus nerve collects information about breathing, heart rate, gut, etc.
• Sends information to the brain for decision making
• Foods rich in L‑tyrosine elevate mood and motivation
• Hidden sugars can disrupt dopamine systems

Serotonin and the Brain-​​Body Connection

• More than 90% of serotonin is in the gut
• Most serotonin that impacts mood is in the brain’s Raffe nucleus
• Serotonin makes us feel comfortable and content
• Antidepressants like Prozac, Zoloft, and Paxil are selective serotonin reuptake inhibitors (SSRIs)
  • Prevent reuptake of serotonin, leading to elevated serotonin levels
  • Can be useful for depression and other clinical disorders
  • Side effects: blunting affect, reduced appetite, reduced sex drive

Serotonin in the Gut and Brain

• Serotonin in the gut impacts serotonin in the brain
• Carbohydrate-​​rich foods can increase serotonin levels

• No reliable at-​​home tests for serotonin and dopamine levels currently available
  Foods, Dopamine, and Serotonin

• High protein, moderate fat, low carb meals promote dopamine, acetylcholine, and epinephrine production, leading to alertness

• Foods containing tryptophan promote serotonin release, helping with sleep and relaxation 
  • Examples: white meat, turkey, starchy carbohydrates
• 5‑HTP supplements can increase serotonin, but may disrupt natural production and sleep patterns
• Amino acids in food are precursors to neuromodulators, affecting alertness, calmness, happiness, and well-being

Supplements and Their Effects

• 5‑HTP: notable decrease in appetite, decrease in body weight, increase in cortisol (minor effect)
• Mucuna pruriens (velvet bean): contains L‑DOPA, precursor to dopamine 
  • Effects: increase in sperm quality, decrease in symptoms of Parkinson’s disease, increase in subjective well-​​being, increase in testosterone, reduction in prolactin

Emotions and Context

• Emotions can’t be labeled as good or bad without considering context and cultural factors
• Book recommendation: “How Emotions Are Made” by Lisa Feldman Barrett

Gut-​​Brain Connection

• Supplements and nutrients are ingested and metabolized, communicating with the brain through the vagus nerve
• Nerves in the gut sense nutrient content and influence mood and cravings
• Blood-​​brain barrier (BBB) prevents direct access to the brain, requiring ingestion and metabolism of substances to affect mood and emotions

Considerations for Mood Regulation

• Individuals who are anxious and wired may not want to lean on the dopamine-​​adrenaline pathway any further
• Experimenting with different foods and nutrients can help individuals find the right balance for their mood and well-being

• Always consult with a doctor before trying new supplements or making significant changes to diet
  Increasing Dopamine Pathway for Motivation

• Behaviors and proper food choices can help increase dopamine

• Exercise and meditation can improve mood, but are subjective
• Ingesting more L‑tyrosine can increase dopamine production 
  • Can be ingested through food or supplementation

Omega‑3 and Omega‑6 Fatty Acids and Depression

• Omega‑3 to Omega‑6 fatty acid ratio has a profound effect on depression and mood
• Double-​​blind placebo-​​controlled study found: 
  • Adjusting Omega‑3 to Omega‑6 ratio led to less learned helplessness in animals
  • 1000mg of EPA (high in Omega‑3) was as effective as 20mg of fluoxetine (Prozac) in reducing depressive symptoms in humans
  • Combination of EPA and fluoxetine had a synergistic effect in lowering depressive symptoms
• EPA can be found in fish oil, flax seeds, hemp seeds, and chia seeds 
  • 1000mg per day of EPA can be hard to get from food alone
• Side effects of fish oil include fishy breath and potential blood clotting issues 
  • Consult a doctor before starting supplementation

Heart Rate Variability and Depression

• Heart rate variability (HRV) is important for overall health
• High Omega‑6 to Omega‑3 ratio can lead to elevated inflammatory markers and reduced response to antidepressants
• Increasing Omega‑3 to Omega‑6 ratio can: 
  • Lower inflammation markers
  • Improve response to antidepressants, even at low doses
  • Increase heart rate variability

• The gut and autonomic nervous system play a role in the connection between Omega‑3, heart rate variability, and depression
  Study on Nutrition and Micronutrients in the Brain

• Our body is a whole system, and the brain is not working in isolation

• The things we ingest can have a profound effect on our mood, sleep, and overall well-being
• No single compound, nutrient, supplement, or drug can completely shift our experience of life without proper behaviors (sleep, exercise, social connection, food, etc.)

Omega‑3 and Omega‑6 Ratios

• Can have robust effects on our feelings of well-being
• 1000 mg per day threshold of fish oil is beneficial
• Alternative sources of Omega-​​3s: krill oil, chia seeds, flax seeds, grass-​​fed meats
• Concerns about mercury and other contaminants in fish oil; choose a trusted brand

L‑Carnitine

• Most prevalent in meat, especially beef; also available in non-​​meat sources
• Acetylated into a form that can cross the blood-​​brain barrier
• Involved in mitochondrial activation of long-​​chain fatty acids
• Effects on depression, autism, and alcohol dependence
• Can reduce symptoms of fibromyalgia and migraines

Gut Microbiome, Probiotics, and Prebiotics

• Emerging area of research on the gut-​​brain relationship
• Potential for discovering more about how the things we ingest impact the chemicals in our brain and the rest of our body

Importance of Personalized Approach

• Compounds and supplements can be powerful but carry risks for certain people

• It’s essential to find out what’s right for you and consult with a healthcare professional before making any changes to your diet or supplement regimen
  Vagus Nerve and Gut-​​Brain Axis

• Vagus nerve connects sensory information from the body to the brain and sends motor information to control motility, gut, heart rate, and immune system

• Gut microbiome discussion often includes misconceptions
• Microorganisms in our gut are adaptive and exploit our bodies to proliferate
• Viruses hijack the genome to make more of themselves
• Microbiota vary along the length of our digestive tract

Body Plan and Digestive Tract

• Our body is a series of tubes, including the brain and digestive tract
• Digestive tract starts with our mouth and ends with our intestines
• Mucosal lining in the digestive tract sets the rate and quality of digestion and impacts the immune system
• Infections often start in the mucosal lining of the mouth

Gut Microbiome and Neurotransmitters

• Gut microbiome impacts neurotransmitters and neurons in the gut, which signal to the brain and affect dopamine and serotonin
• Research is focused on understanding the impact of food on the gut microbiome
• Supporting a healthy gut microbiome is good for mood, digestion, and immune system function
• Probiotics can be beneficial, but more is not always better; brain fog can result from excessive probiotic intake
• Fermented foods are a great source of probiotics

Psychiatric Illnesses and Autism Spectrum

• Healthy gut microbiota can improve symptoms of certain psychiatric illnesses and conditions along the autism spectrum
• Effects are likely due to improved immune system function and conditions in which neurons sense nutrients and convey information to the brain

Artificial Sweeteners and Gut Microbiome

• Study in Nature showed that saccharine can disrupt the gut microbiome, increasing inflammatory cytokines
• Negative effects of artificial sweeteners on the gut microbiome were restricted to saccharine; other sweeteners like aspartame, sucralose, stevia, and monk fruit may have lower or no negative effects
• Saccharine doesn’t kill the microbiome, but shifts it, making the environment more favorable to harmful bacteria

Ketogenic Diet and Gut Microbiome

• Switching to a ketogenic diet can cause a shift in the gut microbiome
• Some people feel better on a ketogenic diet, while others feel worse

• Individual responses to the ketogenic diet can vary
  Positive Shifts in Mood and Affect with Diet Changes

• Transition to a more plant-​​based diet can improve mood and affect

  • Enrichment of fiber in plant-​​based diets creates shifts in the gut microbiome
• Processed foods, whether animal or non-​​animal based, can lead to overconsumption of calories and weight gain 
  • Affects the nervous system and gut microbiome

Individual Differences in Diet and Microbiome

• Some people’s microbiome and mucosal lining improve with meat-​​based diets, while others do better on plant-​​based diets 
  • Likely influenced by genetic makeup and early life experiences
• Fermented foods support the microbiome 
  • Recommended to ingest at least two servings per day
• Supplementation at low levels can be beneficial, but high levels may cause brain fog

Fasting and the Gut Microbiome

• Fasting depletes the gut microbiome 
  • Longer periods of fasting (1–3 days) have more significant depletion
• Replenishing the microbiome after fasting may lead to higher levels than before 
  • Gradual transition back to consuming nutrients is recommended

Belief Effects on Physiology

• Study by Alia Crumb at Stanford: 
  • Two groups given the same milkshake, but one group was told it was low calorie, and the other was told it was high calorie
  • High calorie group had a more robust effect on reducing grelin (hunger hormone) levels
  • Belief about the content of the shake impacted their physiology
• Another study by Dr. Crumb: 
  • Hotel workers were divided into two groups and watched a short film 
    • One group was told their work was important and helped people feel comfortable
    • The other group was told their work was good for their health
  • Eight weeks later, the group that believed their work was good for their health had lower blood pressure, lost body fat, and reported enjoying their work more
  • Beliefs and mindset can impact physiology and overall well-being

Conclusion

• Find the diet that works best for you and supports your gut microbiome
• Consider the impact of fasting on the gut microbiome and transition back to consuming nutrients gradually

• Be aware of the power of belief and mindset on physiology and overall well-​​being
  Belief Effects on Health and Weight Loss

• Belief effects are not about lying to yourself

  • Subjects in experiments didn’t have prior knowledge about ghrelin or effects of daily routine on weight loss and blood pressure
  • Must be naive to the information for belief effects to work
• Mind and body have a fascinating interplay 
  • How the body reacts to food and substances impacts the brain and how we feel
  • How we feel impacts our body’s reactions at core physiological levels
  • Beliefs about substances, foods, and nutrients can have a profound effect on their impact