The Ketogenic Diet and Mental Health
The ketogenic diet is a high-fat, moderate-protein, and very low-carbohydrate diet. The goal is to shift your body into a state of ketosis, where it primarily burns fat for energy instead of carbohydrates. Normally, your body uses glucose (from carbohydrates) as its primary energy source. When you drastically reduce carb intake, your body doesn't have enough glucose to fuel itself, so it begins to break down fat into ketones—small molecules that can be used for energy instead. This process is known as ketosis.
The ketogenic diet was first developed in the 1920s as a treatment for epilepsy. Researchers at the Mayo Clinic were looking for a way to mimic the effects of fasting, which at the time was an established method for reducing seizure frequency. However, it was difficult to maintain for patients, and as a result, the diet was designed to replicate the biochemical effects of fasting by inducing ketosis.
Fast-track to the last 5-10 years and we’re now seeing scientific investigations explode shifting the the focus more on severe psychiatric conditions, such as bipolar disorder, schizophrenia and depression.
What is it about the keto diet that is so therapeutic for brain health specifically?
The ketogenic diet has been shown to reduce something called ‘excitotoxicity’ in the brain, which can happen when a specific neurotransmitter - glutamate - is excessively stimulated and the brain is unable to clear it efficiently. Under normal conditions, glutamate is released into synapses (the space between neurons, or brain cells) to transmit signals to neighbouring neurons, and once it has exerted its function it is then broken down and cleared.
This excessive stimulation can lead to a cascade of problems, such as neuronal death, increased oxidative stress, inflammation and mitochondrial damage (think of the mitochondria as the batteries of our cells), which can go on to cause a myriad of brain-related symptoms (mania, low mood, hyperactivity, poor cognition) and has been linked with diagnoses, such as Alzheimer’s Disease, Parkinson’s and MS.
The keto diet supports brain health and prevents excitotoxcity by doing the following things:
Reduces oxidative stress: Burning ketones as an energy source is less likely to cause oxidative stress compared to glucose. Excitotoxicity, is exacerbated by high glucose levels and metabolic dysfunction.
Reduces Glutamate Excitotoxicity: The ketogenic diet reduces the activation and release of glutamate, helping to modulate neurotransmitter activity and reduce the harmful effects of excessive glutamate release.
Improves Mitochondrial Function: Ketones support mitochondrial efficiency. Mitochondria are responsible for generating energy in brain cells, and their dysfunction can contribute to excitotoxicity. A more efficient mitochondrial system reduces oxidative stress and helps cells manage energy demands more effectively, which can protect neurons from the damaging effects of excitotoxicity.
Anti-inflammatory Effects: Chronic inflammation in the brain can worsen excitotoxicity. The ketogenic diet has been shown to have anti-inflammatory effects, which can reduce neuroinflammation and protect against the harmful processes that lead to neuronal damage. This is partly due to the ketones' ability to influence the brain's immune response, decreasing the release of pro-inflammatory cytokines that contribute to excitotoxicity.
Increases GABA Activity: The ketogenic diet can enhance GABA (gamma-aminobutyric acid) activity in the brain. GABA is the main inhibitory neurotransmitter and counteracts excitatory signals, such as those mediated by glutamate. Think of GABA as the neurotransmitter that helps us relax and wind down. By promoting GABAergic activity, the keto diet helps to balance the excitatory-inhibitory neurotransmitter system, reducing the risk of excitotoxicity.
Neuroprotective Effects: Ketones have direct neuroprotective effects. For example, ketones have been shown to activate pathways that promote neuronal survival and stress resilience. This helps neurons withstand the cellular damage caused by excitotoxicity, supporting brain health and reducing the likelihood of long-term damage.
What factors can contribute to excitotoxicity in the brain?
Environmental toxins, such as heavy metals, pesticides, solvents, and air pollution, can contribute to excitotoxicity by increasing oxidative stress and inflammation in the brain, which can significantly disrupt the balance of neurotransmitters in the brain, particularly glutamate.
We also know that there are endogenous toxins (toxins made in the body) that can contribute to excitotoxicity. For example, conditions that cause chronic inflammation, and therefore the prolonged release of pro-inflammatory cytokines, such as autoimmune diseases or infections, can enhance glutamate release and receptor activity, which contributes to excitotoxic damage.
Important note on interactions between psychiatric medications and the keto diet
If you’re on a psychiatric medication, it’s important to understand how the keto diet will impact how your body metabolises the medication.
SSRIs and SNRIs
For example, it is well known that being on the keto diet has an anti-depressant like effect on the brain, and so therefore it may alter levels of serotonin. This means that if you’re on an SSRI or SNRI, you may need to alter the dosage at some point.
Antipsychotics / Antiepileptics
We also know that the ketogenic diet can increase lithium toxicity in those taking lithium, a mood stabiliser frequently used on those with bipolar disorder.
Another medication use in psychotic disorders is valproate or depakote - two anticonvulsant medications of which effectiveness may reduce whilst on the keto diet due the fact that it’s main ingredient - valproic acid - is a fat. As the keto diet is high fat, the body gets more efficient at burning fat and so therefore you may end up with lower levels of the medication in the blood, which raises the risk for breakthrough seizures.
ADHD medications
The ketogenic diet can influence the metabolism of medications in the liver, particularly by altering enzyme activity in the cytochrome P450 system, which is responsible for metabolizing many drugs, including Adderall - a drug used to treat ADHD. This could potentially affect how Adderall is processed in the body. The ketogenic diet has been shown to reduce levels of this medication by 50-60%.
Final words…
If you’re thinking of trying the ketogenic diet, it is highly advisable to first let your psychiatrist know (if you’re on medication) and it’s important to work with a practitioner who can guide and orient you. This is because the diet can be tricky to follow, most often in the initial stages when the body is adapting and you may experience side effects. If you want to have a chat about whether the keto diet is the right approach for you, please do not hesitate to get in touch below.
