The ketogenic diet shows promise in reducing the symptoms of bipolar disorder and schizophrenia and reversing metabolic syndrome, results of a new pilot study show.
Participants who adhered to the high-fat, low-carb diet experienced a 30% reduction in psychiatric symptoms and an average 10% reduction in weight.
“We’re seeing huge changes,” first author Shebani Sethi, MD, of Stanford University in Stanford, California said in a press release. “Even if you’re on antipsychotic drugs, we can still reverse the obesity, the metabolic syndrome, and the insulin resistance. I think that’s very encouraging for patients.”
The findings were published online in Psychiatric Research.
Neuroprotective Effect?
The pilot study included 21 participants with schizophrenia (n = 5) or bipolar disorder (n = 16) who were aged 18-75 years. All were currently taking psychotropic medications. Participants were overweight (body mass index [BMI] ≥ 25) and had gained more than 5% of their body mass while taking psychotropic medication, or they had at least one metabolic abnormality, such as insulin resistance or dyslipidemia.
At baseline, participants received a physical and psychiatric evaluation and 1 hour of instruction on how to implement the keto diet, which included 10% carbohydrate, 30% protein, and 60% fat.
Investigators monitored blood ketone levels at least once a week and defined participants as keto-adherent if their levels were 0.5-5 mM for 80%-100% of the times they were measured.
Health coaches checked in with participants for about 5-10 minutes each week to answer diet-related questions.
Psychiatric assessments, which included mood rating and global functioning scales, were completed at baseline, 2 months, and at the end of the 4-month study.
The research team tracked participants’ adherence to the diet by weekly measurement of blood ketone levels.
By the end of the trial, 14 patients had been fully adherent with the diet, six had been semi-adherent, and only one had been nonadherent. Higher ketone levels, suggesting greater adherence, correlated with better metabolic health.
As measured by the Clinical Global Impression-Schizophrenia and Clinical Global Impression for Bipolar Disorder–Overall Severity, participants experienced a 31% reduction in symptom severity (P < .001). Overall, 43% (P < .02) of participants achieved recovery as defined by the Clinical Mood Monitoring Form criteria: 50% of the adherent group and 33% of those who were semi-adherent.
Metabolic Benefits
Initially, 29% of participants had metabolic syndrome and more than 85% had co-occurring medical conditions such as obesity, hyperlipidemia, or prediabetes. By the end of the study, none met criteria for metabolic syndrome.
On average, participants experienced a 10% reduction in weight and BMI. Waist circumference was reduced by 11%, fat mass index dropped by 17%, and systolic blood pressure decreased by 6%. In addition, metabolic markers including visceral fat, inflammation, A1c, and insulin resistance also improved. All outcomes were significant at P < .001 except for systolic blood pressure, at P < .005.
There was also a 20% reduction in triglycerides and a 21% increase in low-density lipoprotein cholesterol (both at P < .02).
The study’s limitations include its small sample size, the lack of control arm, and short duration.
“Mental health and physical health are interconnected and addressing metabolic issues can complement psychiatric treatment to enhance overall well-being. Understanding the
mechanisms and potential synergies between psychiatric treatment and metabolic improvements can also inform the development of more effective interventions,” the researchers wrote.
The study was funded by the Baszucki Group, Kuen Lau Fund, and the Obesity Treatment Foundation. The authors declare no competing interests.
A version of this article appeared on Medscape.com.