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 basic research to clinical practice. Image credit: artem evdokimov / Shutterstock.com
The health benefits of KD
The KD is characterized by low carbohydrate, high fat, and moderate protein, accounting for 5–10%, 65–80%, and 20–25% of total energy, respectively. Several studies have shown the benefits of KD in the management of various pathological conditions.
For example, KD offers potential benefits for cancer treatment, cardiovascular health, and reducing inflammation. In addition, KD has been associated with both neuroprotective and anti-inflammatory effects that could prevent and co-treat a wide range of psychiatric disorders.
Conventional therapeutic approaches to managing mental health disorders include psychotherapy, pharmacotherapy, or both, each of which can have unwanted side effects for some individuals. Therefore, there is an urgent need to develop new therapeutic methods that lead to better outcomes and tolerability.
About the study
The present study included 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 effective and representative keywords to identify relevant animal and human studies.
Some of these keywords included “ketogenic diet AND stress,” “ketogenic diet AND psychiatric illness,” “ketogenic diet AND mental disorders,” “ketogenic diet AND neurobiological outcomes,” and “carbohydrate restriction OR calorie restriction.” Articles published in English were included in the analysis, while those published in peer-reviewed journals, reviews and editorials were excluded.
Study findings
Across various mental health disorders, CD interventions are associated with both similarities and dissimilarities in their therapeutic efficacy.
Overall, animal studies have shown that KD effectively alleviates 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 discrepancy in results could be due to differences in sample size, study design, participant characteristics, duration of intervention, and heterogeneity of depressive disorders among 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 CD interventions, not all studies have shown significant improvements. In addition to improving heterogeneity in study designs, the molecular mechanism by which KD exerts its anxiolytic properties also requires additional investigation.
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 chronically stressed KD-fed rats. Taken together, these results highlight complex associations between behavior, neuroendocrine pathways, and metabolism.
For schizophrenia, KD has been shown to provide beneficial effects in both animal and clinical studies.
There remains a lack of evidence regarding the effectiveness of KT in the treatment of bipolar disorder. Although some studies have reported a reduction in symptom severity and improvements in mood stability, the reliability of these findings needs to be established using more extensive randomized clinical trials.
Current research investigating the effects of CD on psychiatric illness has used a variety of 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 depressive symptoms, cognition, social and eating behaviors, and stress-related behaviors .
conclusions
While there is some evidence for a 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 need to mitigate methodological limitations of existing studies, optimize treatment protocols, and explore the molecular mechanisms through which KD may influence mental health disorders. Additional research is also needed to establish the safety and effectiveness of CD in psychiatric care.
Journal Reference:
- Chrysafis, M., Iakovides, X., Papadopoulou, S.K. et al. (2024) The potential effects of the ketogenic diet in the prevention and co-treatment of stress, anxiety, depression, schizophrenia and bipolar disorder: From basic research to clinical practice. Nutrients 16(11); 1546. doi: 10.3390/nu16111546
