Ketogenic diet improves health in schizophrenia and bipolar disorder

In a recently published study in the journal Psychiatry Research, a team of researchers assessed the effects of a ketogenic diet (KD) on metabolic and psychiatric health in people with schizophrenia or bipolar disorder who have existing metabolic abnormalities.

Millions of people around the world suffer from severe mental illnesses such as schizophrenia (24 million) and bipolar disorder (50 million). Current treatments often result in resistance or metabolic side effects, leading to treatment failure. Traditional antipsychotics may shorten life expectancy despite their long-term benefit in schizophrenia. The ketogenic diet, effective in treating epilepsy, offers an alternative source of energy for the brain by reducing neuronal excitability and inflammation. Emerging evidence suggests that metabolic dysfunction underlies psychiatric illness. Given the high risk of metabolic syndrome in people with severe mental illness, further research into the potential of KD to improve metabolic and psychiatric outcomes is essential.

The study involved 23 people aged 18 to 75 years, all of whom were taking psychotropic medications and met criteria for being overweight or having metabolic abnormalities. Twenty-one people completed the study (5 with schizophrenia and 16 with bipolar disorder). Participants received educational materials, cookbooks, resources and a personal trainer.

KD consisted of 10% carbohydrates, 30% protein and 60% fat, with the goal of achieving blood ketone levels of 0.5 to 5 mM. Compliance with the diet was monitored by the level of ketosis. Blood samples were analyzed to assess metabolic markers, and vital signs, body composition and psychiatric assessments were recorded at baseline, two and four months. Remote participants self-reported data and visited local facilities to conduct assessments. The study also assessed the potential side effects of KD compared to psychiatric medications and was approved by the Stanford University Institutional Review Board and registered with ClinicalTrials.gov (NCT03935854).

Statistical analyzes were performed using standard methods in Microsoft Excel, and data were recorded in Research Electronic Data Capture (REdCap). Paired t-tests were used to compare initial and final measurements, and McNemar's test and chi-square analysis were used for nominal data. The study was exploratory in nature and was not powered for significance, but p values

Data analysis included twenty-three participants, 5 with schizophrenia and 16 with bipolar disorder. 14 participants fully adhered to the CD, 6 partially adhered, one did not adhere.

Initially, 29% of participants met criteria for metabolic syndrome. At the end of the study, none of the participants met these criteria (p < 0.05). Main metabolic outcomes included a mean 10% reduction in weight (p

Psychiatric outcomes showed a 31% improvement on the Clinical Global Impression Severity Scale (p < 0.001). The recovery rate increased from 33% at baseline to 75% at the end of the study, with 100% recovery observed in the full diet group. Overall, 43% of participants achieved recovery (50% among fully adherents, 33% among partially adherents), and 79% showed significant improvement in symptom severity (92% among fully adherents, 50% among partially adherents). Among participants with bipolar disorder, 69% showed an improvement in severity of more than 1 point, and the recovery rate increased from 38% to 81%. All fully adherent participants with bipolar disorder had recovered or were in recovery by the end of the study. Psychiatric improvements included a 17% increase in life satisfaction (p

Common side effects of KD, such as headache, fatigue and constipation, were reported at the beginning, but decreased to minimal levels after the third week. Qualitative feedback from participants highlighted significant improvements in anxiety, mood stabilization, and overall quality of life, with some expressing profound personal transformations.

A study of people with schizophrenia and bipolar disorder who received KD along with psychiatric treatment showed significant improvements in psychiatric and metabolic parameters. Psychiatric results showed a 31% improvement in mental illness severity, with 79% of symptomatic participants showing significant improvement, especially among those on the diet. Metabolic outcomes included reductions in weight, waist circumference, systolic blood pressure, fat mass index, BMI, visceral adipose tissue, HbA1c, and triglycerides. Overall KD side effects decreased after three weeks. These results suggest that KD is a viable and effective adjunctive treatment to improve the psychiatric and metabolic health of this population.