How Food Affects Your Mood

Every aspect of our lives is controlled by our brain—our thoughts, movements, breathing, heartbeat, senses and more. And like everything else in our bodies, the brain requires energy—in the form of the foods we eat. By paying close attention to the foods we eat, we’re able to control how well our brains perform—physically, intellectually, and emotionally. Research has shown that there is a correlation between mood and food.¹

Below we explore multiple ways that food affects your mood.

Food helps dictate your gut health

Today, the rapidly growing field of nutritional psychiatry is finding there are many connections between what we eat and the types of bacteria that live in our guts – which affect how we feel and even, how we behave.

The inner workings of our digestive systems don’t just help us digest food, they also may impact our emotions. Our bodies produce serotonin, a neurotransmitter that helps regulate sleep and appetite, mediate moods and inhibit pain. 95% of serotonin is produced in our gastrointestinal tract,² which is lined with millions of nerve cells, or neurons.

The function of these neurons and the production of serotonin is highly influenced by the billions of “good” bacteria that make up our intestinal microbiome. These bacteria play an essential role in our health. They protect the lining of our intestines and provide a strong barrier against inflammatory signals and “bad” bacteria. They also improve how well we absorb nutrients from food, and activate neural pathways that travel directly between the gut and brain.³

How probiotics can help your gut and mood

Recent research shows that when people take probiotics, which contain “good” bacteria, their anxiety levels, perception of stress and mental outlook improve, compared with those who do not take probiotics. Conversely, when the balance between good and bad bacteria is disrupted, cognitive and mood problems may occur.⁴

Studies have shown the risk of depression is 25-35% lower in those who eat a traditional Japanese or Mediterranean diet, compared to a typical Western diet.⁵ Scientists account for this difference because these traditional diets tend to be high in fruits, vegetables, and primarily unprocessed foods. Many unprocessed foods are fermented, and therefore act as natural probiotics. The good bacteria in fermented foods influence how we digest food, absorb nutrients, and can even affect the level of inflammation throughout our bodies, leading to improved mood and energy levels.

Food can cause mood swings by impacting your blood sugar

Glucose, or sugar, fuels your brainpower. In that way, there is an innate relationship between your glycemic levels (which you may know as your blood sugar) and your mood. Poor glycemic regulation, or blood sugar fluctuations, have been associated with symptoms like worry, anxiety and irritability.⁶

An easy way to experience less blood sugar variability in your body is to eat foods high in fiber (more prevalent in unprocessed foods). High-fiber foods are harder for your body to digest, and thus take longer for your body to process. This more gradual process has a much lower impact on your blood sugar levels, meaning a smaller and less sudden blood sugar spike.⁷

What to eat to control your glycemic levels

You may reduce the frequency and severity of fluctuations between high and low blood sugar levels through several foods and diets. Try switching from a Western diet to a traditional Japanese and/or Mediterranean diet, as they are largely free from processed and refined foods and sugars. Consuming protein is another option with less of an impact on glycemic levels.⁶

Food can cause higher anxiety by producing oxidative stress

In addition to inhibiting our bodies’ regulation of insulin, refined sugars also promote oxidative stress.⁸ Oxidative stress generally occurs when the body uses oxygen, which can generate reactive oxygen species (ROS). ROS are byproducts of energy utilization that can often be damaging to cells like the neurons in our brain.

Research has associated oxidative stress with high anxiety levels and some anxiety disorders, such as panic disorder and obsessive-compulsive disorder (OCD).⁹ This suggests that the oxidative stress system can affect the regulation of anxiety. Research has even pointed to a possible causal relationship between oxidative stress and emotional stress.

What to eat to reduce oxidative stress

Foods that contain fatty acids, antioxidants, vitamins and minerals can protect our cells from oxidative stress. You can start by making sure that you’re consuming enough antioxidants in your diet. Experts recommend eating a variety of fruits and vegetables everyday.⁸

Food can resemble antidepressants through certain nutrients

Studies have connected twelve nutrients to preventing and lessening depressive symptoms: Folate, iron, magnesium, omega-3 fatty acids, potassium, selenium, thiamine, vitamin A, vitamin B6, vitamin B12, vitamin C, and zinc.¹⁰

Let’s expand on some of these.

Vitamin B6

Vitamin B6 helps your body build and synthesize important neurotransmitters like GABA and serotonin. These two neurotransmitters have been shown to improve symptoms of anxiety, which largely come from studies utilizing drugs that affect serotonin levels like SSRIs and drugs that increase the activity of GABA, like benzodiazepines.¹¹

Foods rich in vitamin B6

An important distinction to note about vitamin B6: you can only get it through food. Some animal and plant food options to get your dose of vitamin B6 are:

• Meats, such as chicken, beef liver, salmon and tuna
• Chickpeas
• Dark leafy vegetables (which double for your source of potassium)
• Starchy fruits and vegetables, like bananas and potatoes¹²

Magnesium

According to researchers “Magnesium is essential to ensure the correct functioning of all human cells…magnesium plays a critical role in brain function and mood since it is essential for optimal nerve transmission.”¹³ Some clinical and preclinical studies suggest that magnesium may produce antidepressant-like effects similar to prescription medications, but these data are scarce and unfortunately, inconsistent.¹⁴ Some studies suggest the effect of magnesium may produce its effects similar to the antidepressant ketamine.¹⁵ Another hypothesis derived from preclinical studies suggests magnesium deficiency may impair the hypothalamic-pituitary-adrenal (HPA) axis, a core part of the brain which, if dysfunctional, can contribute to the rise of anxiety and depression.¹⁶

One study with rats saw an association of magnesium deficiency and disruptions to the gut microbiome. Those disruptions had cascading effects into the gut-brain axis, leading to depressive symptoms.¹³

Foods rich in magnesium

You can get magnesium through incorporating these foods into your diet, among others:

• Green leafy vegetables
• Fish
• Nuts
• Whole grains¹³

Selenium

Dysregulation of the thyroid has a known association with psychiatric symptoms, such as depression and anxiety.¹⁷ Selenium is involved in the regulation of thyroid hormone, and some authors hypothesize this association may be responsible for selenium’s impact on mood.

More specifically, some studies have linked low levels of selenium with the development of depression.¹⁸ However, some studies also show an increase in depressive symptoms with high levels of selenium. The study authors suggested that these inconsistent findings may be the result of having too little or too much selenium, and that people may need an “optimal” level.

Foods rich in selenium

Selenium is found in various foods such as:

• Seafood, specifically shrimp, halibut, and tuna
• Meats, like turkey, beef liver, and ham
• Cottage cheese
• Eggs¹⁹

Food can boost your mood through flavonoids

Flavonoids are compounds found in your body and in food (often plants) that have shown to reduce mood-related symptoms of depression.

Supporting evidence

A recent meta-analysis (which summarized the results for 36 individual studies on flavonoids and depressive symptoms), found that total flavonoid intake was significantly associated with a reduction in depressive symptoms.²⁰ One study within this meta-analysis focused on comparing flavonoids to the antidepressant fluoxetine. In this study, 30 patients with mild to moderate depressive disorder were given either 6mg of flavonoid or 10mg of fluoxetine. The authors found a significant decrease in depressive scores after 4 weeks of treatment for both compounds, but this effect was significantly larger for fluoxetine at week 6.

Foods rich in flavonoids

You can incorporate flavonoids into your diet through these foods and beverages:

• Tea
• Red wine
• Citrus fruits or juices
• Apples
• Berries²¹

Food can decrease negative moods through vitamin D

Vitamin D and its receptors are found in the hippocampus and prefrontal cortex – regions of the brain responsible for emotional regulation.²² This means vitamin D supplementation may impact mood, and research has shown it can do so positively.

Supporting evidence

In a recently published meta-analysis, authors summarized the results of 41 studies involving 53,235 subjects, in which vitamin D supplementation ≥ 2,000 IU/day appears to reduce depressive symptoms.²³ They went on to specify that these effects appeared to be most potent among individuals diagnosed with major depressive disorder (MDD) and in women with prenatal depressive symptoms. It should be noted that in healthy individuals (those without a diagnosis of MDD or without other major psychiatric or physical conditions) the results actually favored the placebo group.

Foods rich in vitamin D

Alternatively, you can increase your intake of vitamin D through food. Foods rich in vitamin D that therefore may improve your mood are:

• Fish, like salmon, tuna and swordfish
• Egg yolks
• Sardines
• Beverages fortified with vitamin D, often seen in orange juice and dairy milk²⁴

How to Eat to Improve Your Mood

It’s never too late to recognize how foods impact how we feel —not just in the moment, but also over time. To identify specific foods that make us feel bad, we can begin a “clean” diet for two to three weeks—that means no processed foods or sugar. Some people also go dairy-free and/or grain-free to identify food sensitivities.

Then, slowly introduce foods back into your diet, one by one, taking note of any changes in how you feel. Using a food journal will help make this process easier. If you’re taking prescription medications, make sure to note any changes in side effects too – as your diet can impact how well your medications work for you. When introducing more nutritious options, people often notice a change in mood, and cannot believe how much better they feel both physically and emotionally.

Food is one of many things influencing our wellness. Our brains function best when we eat a nutritious and balanced diet.

Our genes can impact how our bodies absorb and process nutrients, how we respond to stress (our immediate stress response as well), how we sleep, and even the number of good bacteria we have in our guts. Learn more about the connection between your genetics and your wellness in our Patient Learning Center.

Sources

1. Correlation between mood and food: A brief diet intervention can reduce symptoms of depression in young adults – A randomised controlled trial (2019)
2. Gut/brain connection: Microbiome and mental health in the modern environment (2016)
3. Percentage of serotonin produced in the gut: Microbes Help Produce Serotonin in Gut (2015)
4. Balance of good and bad bacteria: Gut feelings: How food affects your mood (2019)
5. Depression risk lowers by 25-35% with Japanese or Mediterranean diet: Nutritional psychiatry: Your brain on food (2020)
6. Symptoms produced by poor glycemic regulation: Is Your Mood Disorder a Symptom of Unstable Blood Sugar? (2019)
7. High fiber foods for controlling blood sugar spikes: Carbohydrates and Blood Sugar
8. Emotional effects of oxidative stress: Oxidative stress and anxiety (2009)
9. Preventing oxidative stress: Everything You Should Know About Oxidative Stress (2019)
10. Antidepressant nutrients: Antidepressant foods: An evidence-based nutrient profiling system for depression (2018)
11. Vitamin B6 and pharmacological treatment benefits: Pharmacological treatments for generalised anxiety disorder: a systematic review and network meta-analysis (2019)
12. Foods with vitamin B6: Vitamin B6
13. Background on magnesium: The Role and the Effect of Magnesium in Mental Disorders: A Systematic Review (2020)
14. Inconsistent evidence for magnesium’s antidepressant effects: Magnesium and depression: a systematic review (2013)
15. Magnesium resembling ketamine: Antidepressant-like activity of magnesium in the chronic mild stress model in rats: alterations in the NMDA receptor subunits (2014)
16. Magnesium and HPA axis: Magnesium deficiency induces anxiety and HPA axis dysregulation: modulation by therapeutic drug treatment (2012)
17. Thyroid link to anxiety and depression: Dysregulated thyroid hormones correlate with anxiety and depression risk in patients with autoimmune disease (2021)
18. Background on selenium: Zinc, Magnesium, Selenium and Depression: A Review of the Evidence, Potential Mechanisms and Implications (2018)
19. Food sources of selenium: 15 foods high in selenium ( (2021)
20. Flavonoids reduce depression symptoms: Exploring the Impact of Flavonoids on Symptoms of Depression: A Systematic Review and Meta-Analysis (2021)
21. Foods with flavonoids: Flavonoids
22. Vitamin D in the brain: Effects of vitamin D on mood and sleep in the healthy population: Interpretations from the serotonergic pathway (2020)
23. Meta-analysis of vitamin D and depression: The effect of vitamin D supplementation on depressive symptoms in adults: A systematic review and meta-analysis of randomized controlled trials (2022)
24. Foods with vitamin D: Vitamin D