Diet and Mental Health: Nutrients for Brain and Mood

Written by Dr. Ryan Kneessi, ND

Quick answer: Mental health has many causes, including genetics, life experiences and environment, and diet is one piece. A diet heavy in processed foods can contribute to nutrient deficiencies, gut imbalance and chronic inflammation, all linked with mood. Omega-3s, B vitamins, vitamin D, magnesium, zinc, iron and antioxidants support brain function. Food supports, but does not replace, mental health care.

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Key takeaways

Low levels of key nutrients and an imbalanced gut microbiome can both affect neurotransmitters and brain energy.

Omega-3s, B vitamins and vitamin D each play a role in brain cell structure and mood.

If you are struggling with your mood, the article encourages talking to your provider, and it stresses never stopping psychiatric medication without your prescriber.

How diet affects mental health

Nutrients for brain and mood

Omega-3s (DHA, EPA) support brain cell membranes, and B vitamins (B6, folate, B12) support neurotransmitter production. Vitamin D matters because there are receptors throughout the brain, and magnesium supports nerve transmission.

Zinc supports learning and memory, iron supports brain energy and neurotransmitters, and antioxidants protect brain cells from oxidative stress.

Getting help

If you’re struggling with your mood, talk to your provider or a mental health professional. Never stop psychiatric medications without your prescriber. In a crisis, call or text 988.

Healthy aging lens

A nutrient-dense diet, movement, sleep and social connection all support brain health across the lifespan.

When to see a naturopathic doctor

It may be time to see a naturopathic doctor if you have a chronic inflammatory, autoimmune or digestive condition, or if you have diabetes, kidney disease or take medications affected by diet changes. The same is true if you are pregnant, breastfeeding, or have a history of disordered eating, or if you want a plan tailored to your labs, symptoms and goals.

See a medical provider promptly for severe abdominal pain, signs of an allergic reaction such as swelling or trouble breathing, or fainting.

What the research shows

The first randomized trial of diet change for depression was the SMILES trial by Jacka and colleagues in 2017. Sixty-seven adults with moderate to severe depression, most already in therapy or on medication, received either seven sessions with a dietitian focused on a Mediterranean-style diet or the same number of social support sessions for 12 weeks. Depression scores improved more with diet support, and 32% reached remission compared with 8% in the social support group. The trial was small, and participants knew which support they were getting, so the results need confirmation.

Inflammation is one proposed link between food and mood. In a 2012 randomized, double-blind trial by Kiecolt-Glaser and colleagues, 138 sedentary, overweight adults with an average age of 51 took 1.25 or 2.5 grams a day of omega-3 fats or a placebo for 4 months. The inflammatory marker IL-6 fell by 10% to 12% with omega-3s while it rose by 36% with placebo, but depressive symptoms, which were low to begin with, did not change. This shows an effect on inflammation, not on mood itself.

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Questions to bring to your clinician

These questions can help you get the most out of your next visit.

Are there nutrients we should test that could be affecting my mood or focus?

Which nutrients matter most for my mood and brain health?

Could my diet be affecting how I feel mentally from day to day?

How should food-based support fit alongside any mental health care I receive?

Frequently asked questions

Can diet affect mental health?

Yes, diet is one of several factors that influence mood.

Which nutrients support mood?

Omega-3s, B vitamins, vitamin D, magnesium, zinc and iron.

Can food replace medication?

No. Diet supports, but doesn’t replace, mental health care.

Should I test for deficiencies?

Ask your provider about testing if you have symptoms.

Sources

Jacka FN, O'Neil A, Opie R, et al. A randomised controlled trial of dietary improvement for adults with major depression (the 'SMILES' trial). BMC Med 2017. PMID: 28137247. https://pubmed.ncbi.nlm.nih.gov/28137247/
Kiecolt-Glaser JK, Belury MA, Andridge R, et al. Omega-3 supplementation lowers inflammation in healthy middle-aged and older adults: a randomized controlled trial. Brain Behav Immun 2012. PMID: 22640930. https://pubmed.ncbi.nlm.nih.gov/22640930/
Firth J, et al. The Effects of Dietary Improvement on Symptoms of Depression and Anxiety: A Meta-Analysis of Randomized Controlled Trials. Psychosom Med 2019. PMID: 30720698. https://pmc.ncbi.nlm.nih.gov/articles/PMC6455094/
Tardy AL, et al. Vitamins and Minerals for Energy, Fatigue and Cognition: A Narrative Review of the Biochemical and Clinical Evidence. Nutrients 2020. PMID: 31963141. https://pmc.ncbi.nlm.nih.gov/articles/PMC7019700/
Cryan JF, et al. The Microbiota-Gut-Brain Axis. Physiol Rev 2019. PMID: 31460832. https://pubmed.ncbi.nlm.nih.gov/31460832/
Dantzer R, et al. From inflammation to sickness and depression: when the immune system subjugates the brain. Nat Rev Neurosci 2008. PMID: 18073775. https://pmc.ncbi.nlm.nih.gov/articles/PMC2919277/
Eyles DW, et al. Distribution of the vitamin D receptor and 1 alpha-hydroxylase in human brain. J Chem Neuroanat 2005. PMID: 15589699. https://pubmed.ncbi.nlm.nih.gov/15589699/
MedlinePlus: Mental Health

This article is for educational purposes only and is not medical advice. It does not replace an individual evaluation. Talk with your healthcare provider before starting supplements or changing medications, especially if you are pregnant, nursing, or managing a health condition.