Ketogenic diet shows promise in treating anxiety, depression, and other mental health disorders, study finds

By Dr. Priyom Bose, Ph.D.Reviewed by Benedette Cuffari, M.Sc.May 23 2024

A recent Nutrients journal study reviews the potential beneficial effects of the ketogenic diet (KD) on anxiety, depression, stress, schizophrenia, and bipolar disorder.

Study: The Potential Effects of the Ketogenic Diet in the Prevention and Co-Treatment of Stress, Anxiety, Depression, Schizophrenia, and Bipolar Disorder: From the Basic Research to the Clinical Practice. Image Credit: artem evdokimov / Shutterstock.com

The health benefits of KD

KD is characterized by low carbohydrate, high fat, and modest protein, which make up 5-10%, 65-80%, and 20-25% of total energy, respectively. Several studies have demonstrated the benefits of KD in managing various pathological conditions.

For example, the KD offers potential advantages for cancer treatment, cardiovascular health, and inflammation reduction. Additionally, KD has been associated with both neuroprotective and anti-inflammatory effects that could prevent and co-treat a wide range of psychiatric disorders.

Conventional treatment approaches for the management of mental health disorders include psychotherapy, pharmacotherapy, or both, each of which may have undesirable side effects for some individuals. Therefore, there is an urgent need to develop novel therapeutics that lead to better outcomes and tolerability.

About the study

The current study involved an extensive literature review on the beneficial effects of KD on stress, schizophrenia, bipolar disorder, anxiety, and depression. To this end, scientific databases, including Scopus, PubMed, and Web of Science, were carefully searched using efficient and representative keywords to identify eligible animal and clinical human studies.

Some of these keywords included “ketogenic diet AND anxiety,” “ketogenic diet AND psychiatric diseases,” “ketogenic diet AND mental disorders,” “ketogenic diet AND neurobiological effects,” and “carbohydrates restriction OR calories restriction.” Articles published in English were included in the analysis, whereas those published in non-peer-reviewed journals, commentaries, and editorials were excluded.

Study findings

Across different mental health disorders, KD interventions are associated with both similarities and dissimilarities in their therapeutic efficacy.

Overall, animal studies demonstrated that KD effectively mitigated symptoms of anxiety, depression, stress, bipolar disorder, and schizophrenia. Although KD has shown beneficial effects against depression in animal studies, the available clinical evidence remains mixed.

This divergence in results could be due to differences in sample size, study design, participant characteristics, duration of intervention, and the heterogeneity of depressive disorders among human patients. Thus, randomized and controlled clinical trials, as well as large-scale studies, are needed to determine the potential of KD as a treatment for depression.

Similar differences between animal and clinical studies were observed regarding the anxiolytic effects of KD. Although clinical studies have reported lower anxiety following KD interventions, not all studies showed significant improvements. In addition to improving the heterogeneity in study designs, the molecular mechanism through which the KD exerts its anxiolytic properties also warrants additional research.

The relationship between KD and stress responses is complex. Although one study reported higher adrenal sensitivity and corticosterone levels in KD-fed rodents, another study documented improved cognitive performance and metabolic parameters in KD-fed rats subjected to chronic stress. Overall, these results highlight intricate associations between behavior, neuroendocrine pathways, and metabolism.

For schizophrenia, KD has been shown to offer beneficial effects both in animal and clinical studies.

There remains a lack of evidence on the efficacy of KD in treating bipolar disorder. Although some studies have reported mitigation of symptom severity and improvements in mood stability, the robustness of these findings must be established using more extensive randomized clinical trials.

Current research investigating the effects of KD on psychiatric diseases has utilized varied approaches. For example, while one study examined the complex relationship between sleep, psychiatric diseases, and brain metabolism, another study evaluated the effects of KD on depression symptoms, cognition, social and dietary behaviors, and anxiety-associated behaviors.

Conclusions

While there is some evidence of the beneficial role of KD in the treatment of mental health disorders, more research is needed to establish its clinical utility. A key limitation of the current study could be the presence of bias due to differences in the methodologies used in the reviewed studies and the limited availability of long-term follow-up data.

Thus, future studies must mitigate the methodological limitations of existing studies, optimize treatment protocols, and investigate the molecular mechanisms through which KD may influence mental health disorders. Additional research is also needed to establish the safety and efficacy of KD in psychiatric care.