Diet and Anxiety: The Unexpected Link Between Nutrition and Mental Health

The case of Ebony Dupas highlights a burgeoning area of health care: the potential connection between diet and mental health. By May 2024, Dupas knew she had a problem, reporting a mild anxiety about her sense of direction and purpose that rapidly escalated into a paranoia she could not shake or explain. Referred by her doctor, Dupas began consulting with several psychiatrists, all of whom considered diagnosing her with generalized anxiety disorder, bipolar disorder, or schizophrenia. Most wanted to prescribe medication right away, but one clinician ordered bloodwork first to see if something else might be going on.

That test revealed she was depleted in magnesium, a micronutrient essential for nerve and brain function. In Dupas’s treatment, her psychiatrist added magnesium and other micronutrients—L-theanine, B-complex vitamins, and omega-3s—along with a small dose of an SSRI. After a couple of weeks, Dupas said she felt clearer and more focused, with less paranoia. Her experience illustrates a broader question: could addressing micronutrient deficiencies support, or even augment, traditional mental health treatments rather than replace them?

Beyond this individual case, researchers say the link between diet and mental health is real but complex. The gut-brain connection means the same environment where food is digested is also where neurotransmitters are produced. The gut generates much of the body’s serotonin and a substantial portion of GABA, neurotransmiters targeted by antidepressants and anti-anxiety medications. As Uma Naidoo, director of nutritional and lifestyle psychiatry at Massachusetts General Hospital, notes, the brain and mental health are no longer seen as problems confined to the head.

Scientists have identified several micronutrients that may influence mood and anxiety, including magnesium, B vitamins, vitamin D, omega-3s, choline, and L-theanine. Yet public health data show that many Americans do not meet recommended intakes for these nutrients. Previous national surveys indicate that as much as 94 percent of the U.S. population does not get adequate vitamin D, 52 percent do not get enough magnesium, and 92 percent fall short on choline. While the connection between nutrition and brain health is clear, robust evidence showing how supplements affect mental health outcomes in humans remains limited and mixed. Studies vary in design, supplement form, dosage, and participant characteristics, which complicates drawing firm conclusions.

The heterogeneity of supplements reflects both the science and the marketplace. Magnesium, for example, is available as citrate, malate, glycinate, oxide, chloride, and more. How well each form delivers magnesium to the brain is still being studied. A 2024 review found that supplemental magnesium is likely useful in the treatment of mild anxiety and insomnia, particularly for people with existing deficiencies; however, the magnitude of benefit across studies is inconsistent, likely because of the many different forms and individual differences. Alexander Rawji, a psychiatrist and lead author of the review, cautions that magnesium should not be viewed as a benzodiazepine replacement and that supplementation should be part of a multipronged treatment approach.

Not all psychiatrists routinely assess diet or nutrition when evaluating patients, and this gap can mean missed opportunities to address simple contributors to mental health symptoms. Uma Naidoo emphasizes that, while nutrition can help, relying on supplements alone carries risks. A healthy, well-balanced diet is the best overall strategy for meeting micronutrient needs, and those seeking to add nutrients should consider whole foods as the first line of defense. Green leafy vegetables, nuts, and legumes can boost magnesium intake; eggs, milk, and whole grains support B vitamins; eggs, beans, and cruciferous vegetables provide choline; fatty fish and fortified foods support vitamin D; and green tea can supply L-theanine.

Public and clinical discussions continue to push for a more integrated view of health—one that recognizes that nutrition can influence brain function and mental health without discounting established treatments such as psychotherapy and pharmacotherapy. The evidence is growing, but researchers say more robust clinical trials are needed to determine how micronutrient strategies should fit into standard care and how best to measure their effects. Until then, nutrition remains a meaningful, evidence-informed tool within a broader treatment plan. Uma Naidoo summarizes the evolving perspective: the brain and mental health are interconnected with the body’s nutrition, not isolated from it.