Nutrition for Depression: Food, Mood, & Bioindividuality
- Jamie Menzel
- Jan 6
- 9 min read
The food we eat is packed with essential nutrients that influence both our physiology and mood— making nutrition one of the most powerful tools we have to support mental health.
Depression is sometimes described as a persistent heaviness, with an ongoing shift towards low mood, motivation, energy, or enjoyment of everyday life. It can feel like a fog that settles in slowly or arrives all at once. While we’ve known for a long time that depression is influenced by numerous biological and environmental factors, including genetics, hormones, life experiences, stress, and trauma, nutrition is being increasingly recognized as an important part of the picture.
Depression is not a personal failing, a lack of willpower, or “all in your head.” It is a complex experience with biological underpinnings, and diet is one meaningful variable we can support. Let's explore the connections between nutrition, neurobiology, and mood, including the roles of inflammation, neurotransmitters, nutrient cofactors, and gut health, to provide a clear, science-informed foundation you can use in your own life— and to support those you love.
Diet, Neurobiology, & Depression: A Road Map
Depression: A Tale as Old as Time
Across history, depression has been attributed to everything from spiritual imbalance to “melancholic humors” to psychoanalytic conflict. It wasn’t until the 20th century that depression became medicalized, and pharmaceutical treatments were developed. Today, we recognize depression as a multifaceted condition shaped by biology, environment, and lived experience.
This historical shift paved the way for modern research in brain chemistry, inflammation, neuroplasticity, and nutritional psychology, the fields that now help us understand how diet and lifestyle influence our mood and mental health in powerful ways.
Is Depression Really a “Serotonin Deficiency”?
Many people were taught that depression is caused by low serotonin. While serotonin is certainly involved, the “serotonin hypothesis” has not fully held up to scrutiny. Studies show that not everyone with depression has low serotonin, and not everyone improves with serotonin-targeting medications.
Serotonin is important, don’t get me wrong. It plays a central role in mood, sleep, digestion, appetite, and emotional regulation. However, rather than a simple deficiency problem, serotonin is part of a larger biochemical ecosystem that is strongly influenced by our nutrition, and its production depends heavily on nutrient availability, inflammation, gut health, and many other factors.
Neuroplasticity: Finding New Paths Forward
One of the most fascinating findings in modern depression research is the role of neuroplasticity, which is the brain’s ability to adapt, grow, and strengthen neural connections.
Chronic stress, inflammation, and a sedentary lifestyle can reduce neuroplasticity, especially in regions like the hippocampus and prefrontal cortex. People may experience this as brain fog, memory lapses, slowed cognition, or difficulty concentrating.
On the flip side, there are also factors that increase neuroplasticity, including a balanced diet, specific nutrients, such as omega-3 fatty acids, B vitamins, and magnesium, as well as regular exercise, adequate sleep, learning new skills, and spending time in nature.
Nutrition can support neuroplasticity in two major ways:
1. Providing raw materials for neurotransmitter production
(e.g., tryptophan → serotonin; tyrosine → dopamine)
2. Reducing inflammation and oxidative stress
(which otherwise impair synaptic function and neuronal resilience)
The Tryptophan Pathway: A Nutrition–Mood Superhighway
Tryptophan, an essential amino acid found in turkey, chicken, dairy, seeds, and legumes, is the precursor to serotonin and melatonin. But, it’s not always a straight path.
It can flow down two major routes:
1. The Serotonin Pathway
When the body is well nourished and inflammation is kept under wraps, tryptophan is converted into serotonin, with vitamin B6, iron, and vitamin C acting as nutrient cofactors. Some serotonin then becomes melatonin, supporting sleep and circadian rhythms.
2. The Kynurenine Pathway
Under inflammatory conditions, the enzyme IDO diverts tryptophan away from serotonin and toward kynurenine. Some downstream metabolites of kynurenine, like quinolinic acid, can be neurotoxic, increase oxidative stress, and worsen mood. This helps explain why anti-inflammatory diets may prevent and improve symptoms associated with depression.
Inflammation → reduced serotonin → altered mood.
The Microbiome’s Influence on Mood
Your gut bacteria also play an active role in regulating tryptophan metabolism and serotonin production. As mentioned in a previous blog post, approximately 95% of our body’s serotonin is produced in the gut.
In addition to boosting mood, serotonin has numerous jobs throughout the body, including regulating digestion, promoting gut motility, and taking an active part in gut–brain signaling.
Some of the ways that the gut microbiome influences mood include:
Tryptophan metabolism: Certain bacteria convert tryptophan into indoles that influence the immune system and brain.
Short-chain fatty acids (SCFAs): Produced from fiber and written about in a previous blog post, SCFAs reduce inflammation and support gut barrier integrity.
Neurotransmitter precursors: Some microbes produce GABA and other compounds that send signals to the brain via the vagus nerve.
Inflammation modulation: A balanced and diverse microbiome keeps the immune system regulated and reduces IDO activation.
This is one reason why anti-inflammatory dietary patterns, not single foods, are such effective interventions for mental health.
Evidence From the SMILES Trial
The groundbreaking SMILES trial, published in Australia in 2017 and led by Felice Jacka, was the first randomized controlled trial to test whether dietary changes could improve symptoms of depression.
Participants with moderate to severe depression received either:
A modified Mediterranean-style diet with the support of a dietitian, or
A social support “befriending” protocol.
After 12 weeks:
The diet group improved their depression scores significantly.
One-third of participants achieved full remission.
Improvements were not related to weight changes.
The more their diet improved, the better their mood became.
This study helped establish nutrition as a legitimate part of depression treatment, both as an alternative and adjunct to talk therapy and medication.
Nutrients That Support Mood and Brain Health
While a balanced dietary pattern matters the most overall, specific nutrients also support mental health by playing essential roles in neurotransmitter synthesis, inflammation regulation, and neuroplasticity.
Here are some big players:
Omega-3 Fatty Acids (EPA & DHA)
Found in fatty fish, walnuts, flaxseeds, hemp hearts, and chia.
They support mood by:
Reducing inflammation
Increasing BDNF (a factor in neuroplasticity)
Supporting membrane fluidity for neurotransmitter signaling
Modulating serotonin and dopamine activity
EPA tends to have the strongest evidence for depression.
Vitamin D
Produced through sunlight and found in fatty fish, egg yolks, and some mushrooms.
Vitamin D:
Influences serotonin synthesis
Modulates inflammation
Supports circadian rhythm
Helps regulate the HPA axis (a factor in stress)
Low levels of vitamin D are consistently associated with higher risk for depression.
Vitamins B6, B12, and Folate
Found in leafy greens, legumes, whole grains, meat, and fish.
These vitamins are required for:
Serotonin, dopamine, and norepinephrine production
Methylation and gene regulation
Healthy homocysteine metabolism (a factor in inflammation)
Energy production
Individuals with MTHFR or COMT SNPs may have altered needs.
Magnesium
Found in leafy greens, nuts and seeds, >70% dark chocolate, beans, and legumes.
Magnesium:
Regulates serotonin activity
Calms the stress response
Reduces inflammation and oxidative stress
Supports sleep
Low magnesium is extremely common and consistently linked to anxiety, irritability, and low mood.
Zinc
Found in oysters, pumpkin seeds, nuts, meat, beans, and dairy.
Zinc is needed for:
Neuroplasticity
GABA and glutamate balance (a factor in stress)
Neurotransmitter synthesis
HPA-axis regulation
Even mild deficiency can affect focus and mood.
Iron
Found in red meat, poultry, lentils, beans, tofu, and spinach.
Iron deficiency can impair:
Oxygen delivery to the brain
Dopamine and serotonin synthesis
Cognitive function
Energy production
Iron deficiency anemia and low ferritin levels are both associated with depression, especially in menstruating individuals. Add vitamin-C containing foods to plant-based sources to boost bioavailability.
Evidence-Based Herbal Support
Herbal medicine can provide gentle, meaningful support, but interactions matter.
St. John’s Wort
Effective for mild to moderate depression, but interacts with many medications, including SSRIs, SNRIs, birth control, and immunosuppressants.
Saffron
Shown to improve depression symptoms with anti-inflammatory, antioxidant, and serotonin-modulating effects. Generally well tolerated but may interact with SSRIs.
Rhodiola
An adaptogen that supports energy, neuroplasticity, and stress resilience. Not suitable for individuals with bipolar disorder or certain medications.
Always consult a physician before combining herbs with medication.
Additional Ways to Support Neurobiology
Nutrition is powerful, but it’s only one piece of the puzzle. These lifestyle strategies help support neuroplasticity, reduce inflammation, promote neurotransmitter balance, and enhance stress resilience in additional important ways:
Connection
Healthy relationships and adequate social support increase oxytocin, reduce stress hormones, and promote emotional regulation.
Nature
Sunlight boosts serotonin and vitamin D, while green spaces activate the parasympathetic nervous system and lower cortisol.
Movement
Regular exercise increases BDNF, regulates dopamine and serotonin, and reduces inflammation.
Intentional Heat & Cold Exposure
Sauna use increases endorphins, the release of heat-shock proteins (a factor in stress resilience), and BDNF. Cold exposure activates noradrenaline and can improve alertness and mood.
Stress Management
Chronic stress dysregulates the HPA axis, while mindfulness, breathwork, and relaxation techniques help recalibrate the stress response.
Sleep
Sleep is foundational for neurotransmitter balance, emotional processing, and keeping inflammation in check.
The Bigger Picture
When it comes to navigating depression, nutrition can be an important part of the healing process. The food we eat directly impacts our neurotransmitters, hormones, gut health, and mood. When combined with social connection, enjoyable movement, and other supportive daily practices, nutrition becomes one of the most accessible and empowering tools we have.
Depression is complex, but you don’t have to navigate it alone. If you’d like tailored recommendations to support your unique health goals, I'm here to help. Feel free to book a session, and together, we can explore an approach that works best for you. Supporting your body with food-as-medicine is a powerful place to begin.
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