JAMA: Low-Carbohydrate Diet Helps Ease Schizophrenia Symptoms

A ketogenic diet helps reduce symptoms of depression and schizophrenia, but not anxiety disorders. This conclusion was reached by researchers at St. Michael’s Hospital in Toronto. The findings were published in JAMA Psychiatry.

The authors analyzed data from 50 studies involving more than 41,000 adults from 15 countries. The sample included people with mental health conditions — schizophrenia, major depressive disorder, bipolar disorder, generalized anxiety disorder, and PTSD — as well as participants without psychiatric diagnoses, including patients with obesity. Their conditions were assessed using validated clinical scales.

The ketogenic diet — a dietary regimen high in fats, moderate in protein, and very low in carbohydrates — has long been used as a therapy for treatment-resistant epilepsy. Under such a diet, the brain switches from using glucose to ketone bodies, which affects mitochondrial function, inflammation levels, oxidative stress, and neurotransmitter signaling in the brain.

The new study showed that participants following a ketogenic diet experienced a moderate reduction in depressive symptoms. However, no similar association was found for anxiety disorders. Additional subgroup analyses also did not identify factors that consistently enhanced the diet’s influence on anxiety symptoms.

A ketogenic diet or similar dietary patterns also helped reduce psychotic symptoms and stabilize mood in people with schizophrenia or bipolar-spectrum disorders.

The authors emphasize that ketogenic nutrition may be considered as an additional tool in the treatment of mental health conditions, especially when biochemical ketosis can be maintained. However, the mechanisms underlying these positive effects still require confirmation in long-term clinical studies.