The ketogenic diet (KD) has been around since the early 1920’s, primarily being used to help treat patients with epilepsy (1). It was demonstrated that this diet possessed a neuroprotective effect on the brain, which sparked a lot of interest.
The KD is classified as a high-fat, low-carbohydrate, moderate-protein diet that results in ketosis, a metabolic state that can also be achieved via prolonged fasting. The body ramps up ketogenesis when glucose levels drop in the body. Because the nervous system typically relies on glucose and can’t use fat for fuel, the liver starts to produce ketones (e.g., acetone, acetoacetate, and beta hydroxybutyric) as a secondary fuel source. Once in ketosis, the body switches from primarily burning glucose to relying predominantly on ketones and fats.
This elevation of ketones appears to serve a variety of benefits. In fact, recent evidence has shown the KD to improve both cognitive and motor function following brain trauma in rats (2). Additionally, the KD has been shown to reduce brain inflammation through attenuation of the immune response and increased oxidative stress in mice (3).
With regard to neurological conditions, one randomized, double-blind, placebo-controlled, parallel group study investigated the effects of a ketone supplement on Alzheimer’s disease. These researchers reported that after 45 and 90 days of treatment, patients demonstrated a significant improvement in Alzheimer’s-related symptoms (4). One of the proposed mechanisms behind the beneficial effects of the KD include improved mitochondrial function.
Based on the promising results of the KD on cognitive and neurological function, several groups of researchers started looking at the KD and its potential benefits for psychiatric-related disorders. Recently, a review published in the Journal of Frontiers in Psychiatry summarized the current status of the KD in psychiatry. These researchers collected 15 studies that assessed the effects of a KD in treating a variety of mental disorders, including anxiety, depression, bipolar disorder, schizophrenia, autism spectrum disorder (ASD), and attention deficit hyperactivity disorder (ADHD).
The review consisted of nine animal studies, four case studies, and two human studies. With regard to anxiety, ketone supplementation seemed to reduce anxiety-related behavior in rats. What’s more, preliminary data from both animal and human studies suggest that the KD may significantly reduce symptoms of depression. As far as research on bipolar disorder and ASD, the current body of evidence is split with one study demonstrating beneficial effects and another demonstrating no effect for both conditions. Lastly, for ADHD, one controlled trial in dogs with co-morbid epilepsy showed improved symptoms with the KD. These researchers conclude that while the data as a whole is promising, more research is needed before we can conclusively use the KD to treat mental disorders (4).
This review highlights some of the potential benefits of the KD in psychiatric-related disorders; however, more research is needed before it can be promoted by medical professionals. These researchers pointed out that the majority of research was conducted in animals or small sample sizes in humans, making it challenging to prescribe such an approach. This does not mean the KD serves no benefits for psychiatric-related disorders; rather, future research should focus on large sample sizes in humans to determine the efficacy of the KD for psychiatric-related disorders.
- Wheless JW. History of the ketogenic diet. Epilepsia (2008) 49(s8):3–5.doi:10.1111/j.1528 1167.2008.01821.x
- Zhao Z, Lange DJ, Voustianiouk A, MacGrogan D, Ho L, Suh J, et al. A ketogenic diet as a potential novel therapeutic intervention in amyotrophic lateral sclerosis. BMC Neurosci (2006) 7(1):29. doi:10.1186/1471-2202-7-29
- Hao J, Liu R, Turner G, Shi F-D, Rho JM. Inflammation-mediated memory dysfunction and effects of a ketogenic diet in a murine model of multiple sclerosis. PLoS One (2012) 7(5):e35476. doi:10.1371/journal.pone.0035476
- Bostock, E. C., Kirkby, K. C., & Taylor, B. V. (2017). The Current Status of the Ketogenic Diet in Psychiatry. Frontiers in psychiatry, 8.