Food & Mood

Take Control of Your Mental Health

Dr. Aaron Hartman

December 19, 2023

Man and Woman cooking in the kitchen with colorful vegetables and fruits
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    Our food affects our mood; what we eat directly impacts how we feel.

    Mood disorders are on the rise. These include issues like anxiety, depression, bipolar disorder, and seasonal affective disorder. But many of us also wrestle with milder mood instability, feel easily irritated, experience quick mood swings, or have a general sense of brain fog.

    Whether mild or severe, mood disorders are complex with numerous potential causes (biological, psychological, internal, external, etc.). I don’t want to communicate that food is the only cause of anxiety or depression. In my experience, however, we often fail to recognize enough how significantly our diet affects our mental health.

    This article is intended to shine a light on that critical link between your diet and mental health. I’ll introduce you to some of the problems we face, as well as some solutions to take back control of your mental health.

    Getting to the Root Cause of Mood Dysfunction

    Anxiety and depression are not diseases per se; they are syndromes, which means there can be many different causes of depression, anxiety, and mood swings. 

    A concussion can cause anxiety or depression. Chronic Lyme disease can also cause mood disturbances. Life stressors and personal trauma can cause these types of mood disturbances. Even severe vitamin deficiencies can lead to mood disorders. Understanding these underlying causes of emotional dysfunction is critical to helping people who suffer from these syndromes.

    Three major factors in your body affect your mood:

    • The bacteria in your gut (also known as your gut microbiome)
    • Inflammation
    • Nutrient imbalances

    Leaky Gut: Your Microbiome & Mental Health

    Gut Health & Chemical Signaling in the Brain


    Did you know that 75% of ALL your neurotransmitters are made in your GI tract? Neurotransmitters are chemical messengers that allow our neurons to communicate with each other – they’re the language of the brain. So the fact that our body makes most of these in our gut has been a surprising medical discovery.


    Serotonin is the neurotransmitter that makes you feel happy, relaxed, and content. Medications such as Zoloft, Paxil, and Prozac target this neurotransmitter to treat anxiety, depression, OCD, and even ADHD. A surprising 90% of your serotonin is made in your GI tract!


    Dopamine is your focus neurotransmitter. Medications addressing Attention Deficit Hyperactivity Disorder (ADHD) focus primarily on increasing dopamine. 50% of your dopamine is made in your GI tract!

    Now that we realize an astonishing amount of our brain chemicals are made in our gut, we can start to see why our gut health has such a profound impact on our mood, emotional stability, and ability to focus.

    Leaky Gut = Leaky Brain

    My patients are sometimes surprised when I connect leaky gut to their cognitive health.

    So, what is leaky gut? Leaky gut happens when the tight junctions of the intestinal walls break down. When your gut integrity is weak, toxins and undigested food from your GI tract can leak into your bloodstream. Toxins in your blood can then confuse or overwhelm your immune system, causing systemic inflammation. In other words, your dysregulated immune system begins affecting, even attacking your healthy cells. 

    Diagram of how a Leaky Gut looks like compared to a normal one

    Endotoxemia is the formal medical term for gut-based toxins in the blood resulting in systemic inflammation. But the process I’ve been outlining often happens in varying degrees, with varying cause and effect. Endotoxemia is an extreme case of something unfortunately common.

    When your gut is inflamed, it disrupts the normal production of neurotransmitters noted above. And since 75% of your neurotransmitters rely on a healthy gut, you can see why a leaky gut leads to a leaky brain.

    What Causes Leaky Gut?

    One cause of leaky gut is dysbiosis, an imbalance of bacteria in the gut. Gram-negative bacteria are a category of bacteria naturally more antibiotic-resistant, which also produce a toxin called lipopolysaccharide (LPS). While gram-negative bacteria occur naturally in the gut, when they grow out of proportion, they produce more of the LPS toxin, which then enters the bloodstream causing systemic inflammation. This dysbiosis can be driven by various lifestyle factors such as stress, inadequate sleep, and a poor diet.

    Brain on Fire: The Role of Inflammation in Anxiety & Depression

    We now understand that inflammation is the root cause of most chronic diseases. I’ve written more extensively about inflammation elsewhere.

    Image of a brain with inflammation

    In relation to mood disorders, chronic inflammation is often called “brain on fire.” I’ve used that expression in previous articles on Chronic Inflammatory Response Syndrome (CIRS), which is a severe example of systemic inflammation interfering with our whole body and, especially, our brain.


    Inflammation also affects cortisol, insulin, and glucose control. In other words, inflammation can affect your survival hormones, affecting your emotional state – determining whether you feel safe or must fight or flee.


    We also see that inflammation can cause people to be more impulsive. Brain inflammation negatively affects the prefrontal cortex, the part of the brain that is right above the eyes and is the center of self-control. When the brain is inflamed, the prefrontal cortex doesn’t work as well and impacts executive function.

    Mood Swings 

    Inflammation also causes cytokine levels to increase. These cytokines transfer inflammation from cell to cell. This is why people are often moody when sick. This is actually a cytokine response. But many of us have low-level inflammation that can cause similar symptoms.

    Nutrient Famine: Deficiencies & Mood Disorders

    Are Nutrient Deficiencies Affecting How You Feel?

    Organic Banana

    Several key nutrients directly impact our mental health. These nutrients are necessary for a general sense of well-being, promoting positive mood, diminishing anxiety, controlling depression, allowing us to react well to environmental events, as well as for clarity of thought and focus. Unfortunately, most Americans are deficient in these critical nutrients, which is impacting our mental health.

    B Vitamins

    There are twelve B vitamins. You’ve likely heard of some of them by their other names:

    • B1 — Thiamin
    • B2 — Riboflavin
    • B3 — Niacin
    • B5 — Pantothenic Acid
    • B6 — Pyridoxine
    • B7 — Biotin
    • B9 — Folic Acid

    B vitamins have a direct impact on your cell metabolism, energy levels, and brain function. Deficiency in B vitamins has been linked directly to depression. Unfortunately, 40 – 60% of Americans are deficient in any single B vitamin. Odds are good that all of us are deficient in several of these.

    Vitamin D

    Fruits and Vegetables that are rich in Vitamin C

    Vitamin D is critical for brain function and emotional balance. I have often sung the praises of vitamin D. Unfortunately, about 40% of all Americans are deficient in vitamin D. For people with skin of color, that number gets closer to 82%.

    Vitamin C

    We are one of the few mammals that do not produce our own vitamin C. We have to consume it. Vitamin C comes from fruits and vegetables, which are severely lacking in our modern diet. About 20 – 30% of Americans have an insufficient level of vitamin C.


    Magnesium is another super mineral required for brain function. In fact, we actually use intravenous magnesium to treat seizure disorders, headaches, migraines, and traumatic brain injury. The average American has insufficient levels of magnesium for optimal brain function.

    Trace Minerals

    Zinc, iron, selenium, and other trace minerals are required for producing neurotransmitters.

    Different foods that are colorful


    Phytonutrients are the naturally occurring colors in foods. They’re the red in cranberries and apple peels, the white in onions and garlic, the yellow in squash, the green in leafy vegetables, and the purple in blueberries and blackberries. We’re learning more and more about how these phytonutrients are so important for your body’s production of neurotransmitters, fatty acids, immune function, cancer prevention, and more.

    Solutions & Support

    In this article, I’ve focused on the impact our diet has on brain health and mood disorders through our microbiome and resulting inflammation, and through nutrient deficiencies. It should come as no surprise, then, that the primary solution is to eat the right kinds of foods to support your gut health, reduce inflammation, and bolster critical nutrients.

    Here are a few practical strategies for improving your mental health through your diet.

    Eat More Fiber

    Leafy Green Vegetable and Fruit that are rich in fiber

    Fiber is incredibly important for both gut health and brain health. Your body needs fiber in the gut to produce short-chain fatty acids, like butyrate, acetate, and propionate. These are necessary for proper brain function as well as the healing of the gut lining. These short-chain fatty acids also become a source of energy for the cells in your GI tract.

    The average American consumes about 15 grams of fiber a day. We need 40 – 60 grams for healthy production of short-chain fatty acids. Fiber also supports your gut in making brain-derived neurotrophic factor (BDNF), which is like fertilizer for your brain. We’re discovering that BDNF is critical for neurons to repair, heal, and make new connections. BDNF helps keep your brain stable.

    Eat More Color

    The number one thing you can do to promote a healthy gut microbiome is to eat a nutrient-dense, naturally colorful diet. In addition to being rich in fiber, the natural color in fruits and vegetables feeds healthy bacteria in your gut. Eating colorful foods such as greens, blues, purples, oranges, reds, and yellows is key to reducing inflammation and promoting a healthy gut microbiome.

    Over half of what you eat should be some kind of plant life in various colors: greens, yellows, blues, purples, oranges, and reds. A good rule of thumb is to cover half of your plate with plants. A quarter of it should be clean protein, and maybe a quarter can be some kind of starch – be it a starchy vegetable, fruit, or whole grain.

    Additional Resources for Eating Phytonutrient-Rich Food

    Colorful Foods

    If you’d like to learn more about how you can take charge of your own health by eating colorful, nutrient-dense foods, explore the Phytonutrient Spectrum Food Plan on our website. It’s absolutely free, and you can get started improving your mood with food today. 

    Drink Plenty of Water

    Drinking water is part of your body’s built-in process of detoxification. Many Americans are chronically dehydrated. So, drinking plenty of clean, filtered water throughout the day is a great place to start in supporting your body in detoxification.

    Practice Intermittent Fasting

    Taking breaks from eating, even just for 12 hours a day, greatly impacts the bacteria in your gut. Allowing at least 12 hours between dinner and breakfast is a great place to start in balancing the bacteria in your gut. Fasting also helps to lower the levels of LPS endotoxins I mentioned above. In contrast, grazing throughout the day, snacking between meals, and eating close to bedtime can drive the production of these toxins.

    Supplement Critical Vitamins & Minerals

    As always, I want to remind you that supplements cannot replace the value of a nutrient-rich diet. The recommendations above for eating colorful, fiber-rich foods is primary. 

    Once you’ve begun eating clean, real foods, however, you can further bolster mental resilience by supplementing common nutrients we know affect mental health. You can start with folate, iron, omega-3s, magnesium, potassium, selenium, thymine, vitamin A, vitamin B6, vitamin B12, vitamin C, and zinc.

    If you’re new to supplements, I’ve often been asked where to start. What are the 3–5 must-haves to begin supplementing your health?

    I’m often asked, “If you had to pick only 3 supplements to recommend to me, what would they be?” Here is my answer. You need a quality multi-vitamin, a good source of Vitamin D, and you need to boost your Omega 3 fatty acids. If you can invest further in your health, I also recommend a strong source of probiotics and a detox formula. If you are new to supplements and looking for a safe, reliable way to boost your overall health, here are the must-haves to get started:

    Conclusion: Take Charge of Your Mental Health

    I hope this article on the functional medicine approach to mental health has been helpful to you. 

    Your food really does affect your mood. This may be a wake-up call to change the food you’re eating. But it ought to also feel empowering. You can improve your mood and mental health.

    We’re here to help. Remember, you were made for health!



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