Keto And Brain Fog: What's The Real Link?

The ketogenic diet is a popular eating pattern characterised by low carbohydrate and high-fat consumption. While the keto diet is often associated with weight loss and lower blood sugar levels, it also has several side effects, one of which is brain fog. Brain fog is a term used to describe a range of cognitive symptoms that affect an individual's mental processes, including mental fatigue, hazy thinking, and difficulty with concentration and memory. Starting a keto diet can lead to a decrease in glucose, the brain's primary energy source, resulting in brain fog. Additionally, the transition to a keto diet can cause dehydration and electrolyte imbalances, which are also contributing factors to brain fog. However, the good news is that these symptoms are usually temporary and can be alleviated by proper hydration, consuming bone broth or electrolytes, and increasing salt and water intake.

Keto flu: the body's natural response to carb withdrawal

The keto flu is your body's natural response to carbohydrate restriction. It is a cluster of side effects that occur within the first few weeks of starting a ketogenic diet. Symptoms include brain fog, fatigue and weakness, headaches and dizziness, irritability and mood swings, muscle cramps and soreness, digestive issues, insomnia and poor sleep quality, and chills and sore throat. These symptoms typically last from a few days to two weeks, and up to a month at most.

The keto flu is caused by several changes that occur when you cut out carbs:

• Water and Sodium Flush: When you consume fewer carbs, insulin levels drop, signalling your kidneys to release sodium from the body. This causes a loss of water weight as water shuttles sodium out of your body. The glycogen loss and low insulin levels cause dizziness, nausea, muscle cramping, headaches, and gastrointestinal issues such as diarrhea and constipation.
• T3 Thyroid Hormone Levels May Decrease: T3 is a hormone produced by the thyroid gland. Dietary carbohydrates and thyroid function are closely connected, so when you cut carbs, T3 levels can fall. In conjunction with another thyroid hormone, T4, these hormones regulate your body's temperature, metabolism, and heart rate. As your body adjusts to a ketogenic diet, lower hormone levels may leave you with brain fog and fatigue.
• Increased Cortisol Levels: A ketogenic diet tells your body that you're in starvation mode. In an effort to increase energy levels, your body triggers the release of stress hormones, including cortisol. If you experience irritability and insomnia, that's a clue that your cortisol levels have jumped. As you adjust to utilizing fat and ketones as a new fuel source, your cortisol levels should fall back to their old levels.

The severity of keto flu symptoms depends on your metabolic flexibility, or your body's ability to adapt to different fuel sources without experiencing uncomfortable symptoms. Metabolic flexibility is influenced by genetics as well as lifestyle habits. For example, if you ate a diet low in refined sugar and starches before starting keto, you'll likely experience only mild symptoms. On the other hand, a diet high in sugar and carbs may set you up for greater withdrawal symptoms, especially from sugar.

• Hydration: Water is key to kicking the keto flu, especially if you add some unrefined salt. Aim to drink half your body weight in ounces of water per day. For example, if you weigh 140 pounds, aim for 70 ounces of water per day.
• Bone Broth: Bone broth adds a serving of water to your diet and a dose of electrolytes – sodium and potassium – which will offset some of the discomfort you feel at a cellular level.
• Electrolyte Supplements: Replenishing your electrolytes is a great way to start feeling better fast. Focus on the key players – potassium, magnesium, and sodium. If you aren't getting enough of them from your diet, which can be difficult on a low-carb diet, incorporate them through supplements.
• Eat More Good Fat: Upping your fat consumption can speed up your adaptation phase – you'll start to burn fat instead of glucose more quickly. Try adding MCT oil, which goes straight to the liver after digestion, to your diet.
• Rest and Sleep: A sound night's sleep keeps your cortisol levels in check, which will likely lessen your flu symptoms. Aim for 7-9 hours of sleep per night.
• Mild Exercise and Meditation: The goal here is to reduce cortisol levels, so anything that relieves stress will help. Yoga or gentle walks can do the trick.
• Activated Charcoal: Activated charcoal works to detox your body of any toxins. As you adapt to burning fat for fuel, you'll shed extra body fat, and toxins are stored in this fat. Charcoal assists in swiftly ushering toxins out of your body.
• Exogenous Ketone Supplements: Exogenous ketones aid with fatigue and boost energy levels by raising ketone levels in your blood. Note that they are not a replacement for a proper keto diet.
• Increase Carb Intake: For some people, increasing fat simply won't curb keto flu symptoms. If this is the case, you may need to up your carb intake just a bit. This carb refeeding time gives your body the chance to adjust to burning fat, as it has some glucose (carbs) to utilize during the transition.

Brain fog: a symptom, not a disease

Brain fog is a vague term used to describe a range of cognitive symptoms that affect an individual's mental processes. It is not a recognised medical diagnosis but is often used to describe a feeling of mental cloudiness or lack of clarity. While it is not a disease in itself, brain fog can be a symptom of various underlying conditions, including serious diseases such as Hepatitis C infection, Lyme Disease, chronic fatigue syndrome, fibromyalgia, and even the early stages of liver failure. It can also be caused by harsh treatment regimes, such as chemotherapy, or lifestyle factors such as diet, environment, stress, and sleep deprivation.

The Keto Diet and Brain Fog

The keto diet, characterised by its low carbohydrate and high-fat content, has been linked to brain fog, particularly during the initial phase as the body adjusts to burning fat instead of carbohydrates for energy. This period of adjustment is often referred to as the "keto flu" and typically lasts from a few days to two weeks but can extend to a month in some cases. Symptoms of the keto flu include physical and mental fatigue, irritability, headaches, dizziness, digestive issues, insomnia, and of course, brain fog.

The keto flu is believed to be caused by a combination of factors, including a drop in insulin levels, which signals the kidneys to release sodium and water from the body, leading to dehydration and electrolyte imbalances. Additionally, hormonal changes, specifically a decrease in T3 thyroid hormone levels, and increased cortisol levels, may contribute to the brain fog experienced during the keto flu.

Strategies to Combat Brain Fog on Keto

There are several strategies that can help alleviate brain fog during the transition to a keto diet:

• Proper hydration: Drinking plenty of water and ensuring adequate electrolyte intake, especially sodium, can help combat dehydration and electrolyte imbalances.
• Bone broth: Consuming bone broth provides additional water and electrolytes, such as sodium and potassium, which can help offset cellular-level discomfort.
• Electrolyte supplementation: Taking supplements of potassium, magnesium, and sodium can help address deficiencies and alleviate symptoms such as muscle cramps, dizziness, and fatigue.
• Increase healthy fat intake: Consuming more healthy fats, especially medium-chain triglycerides (MCTs), can speed up the adaptation phase and provide an alternative energy source for the brain.
• Rest and sleep: Getting sufficient and quality sleep helps to regulate cortisol levels, reducing flu symptoms and improving overall well-being.
• Mild exercise and meditation: Engaging in gentle physical activity or stress-relieving practices can help reduce cortisol levels and improve mental clarity.
• Exogenous ketone supplements: Taking ketone supplements may aid in boosting energy levels and enhancing mental clarity by raising ketone levels in the blood.

When to Seek Professional Help

While brain fog is often a temporary side effect of the keto diet, it is important to monitor your symptoms and seek professional advice if they persist or become concerning. Additionally, if you suspect an underlying medical condition may be contributing to your brain fog, it is always best to consult with a healthcare professional for personalised guidance and treatment.

How ketosis works: the body's transition from burning sugar to fat

The ketogenic diet is a popular, low-carbohydrate, high-fat diet that has been embraced by celebrities and health enthusiasts alike. It is characterised by its ability to induce a metabolic state known as ketosis, where the body burns fat instead of glucose as its primary energy source. This transition from burning sugar to burning fat can lead to a range of short-term side effects, including the infamous "keto flu" and its accompanying brain fog. Understanding how ketosis works and the body's transition process is crucial for comprehending the causes of these side effects and finding ways to mitigate them.

Ketosis and the Body's Energy Sources

The human body is incredibly adaptable, and its ability to switch between different fuel sources is a testament to that. Normally, the body's preferred source of energy is glucose, which is derived from carbohydrates in our diet. However, when we significantly reduce our carbohydrate intake, as is the case with the keto diet, the body has to adapt and find alternative energy sources. This is where ketosis comes into play.

During ketosis, the body increases its production of ketone bodies, which are produced by the liver using fatty acids. These ketone bodies become the primary energy source for both neuronal and glial cells in the brain, as they can cross the blood-brain barrier. By using fat as the main energy source, the body increases its fat-burning capacity, often leading to weight loss, one of the primary motivations for adopting the keto diet.

The Transition Phase: From Sugar to Fat Burning

The transition from burning sugar to burning fat doesn't happen overnight. It takes time for the body to adjust and build up the necessary pathways for efficient ketone utilisation. During this transition phase, several changes occur in the body and brain, which can lead to the infamous keto flu and brain fog.

One of the main changes is the drop in blood glucose levels. With a significant reduction in dietary carbohydrates, the brain is temporarily deprived of its main energy source, leading to a state of energy deprivation and, consequently, brain fog. Additionally, the body starts using its glycogen reserves, which are stored with water. This leads to a rapid loss of water weight and can contribute to dehydration, further exacerbating brain fog.

Another crucial aspect of the transition is the increase in ketone body production and utilisation. While the body starts producing ketones promptly, the utilisation of these ketones by the brain takes time. Enzymes and transporters involved in ketone metabolism need to be upregulated, and this process can take days or even weeks. During this adaptation phase, the brain may not be fully equipped to utilise ketones efficiently, resulting in a temporary energy deficit and cognitive impairments.

Mitigating Brain Fog During the Transition

While brain fog and other keto flu symptoms are usually transient and resolve within a few days to weeks, there are strategies to mitigate their impact:

• Proper hydration: Drinking plenty of water is crucial to combat dehydration, which can worsen brain fog.
• Electrolyte supplementation: Sodium, potassium, and magnesium deficiencies are common during the keto transition and can contribute to brain fog. Supplementing with these electrolytes can help alleviate symptoms.
• Increasing fat intake: Consuming more healthy fats, especially medium-chain triglycerides (MCTs), can speed up the transition to burning fat. MCTs are readily converted into ketones, providing an immediate energy source for the brain.
• Adequate rest and mild exercise: Getting enough sleep and engaging in mild physical activities like yoga or gentle walks can help reduce stress levels and lower cortisol, which may contribute to brain fog.
• Exogenous ketone supplements: Taking ketone supplements can help bridge the gap between carb depletion and natural ketone production, providing an immediate boost in energy levels and cognitive function.

The role of ketones: how they can improve brain function

Ketone bodies are an important energy source for the brain, especially when glucose is sparse. Ketones are produced by the liver when the body is deprived of glucose, such as during fasting or when on a low-carbohydrate diet. The brain's utilisation of ketones depends on their concentration in the blood, and so ketogenic diets, ingestion of ketogenic medium-chain fatty acids, or exogenous ketones can facilitate significant changes in the brain's metabolism.

Ketones and neurodegeneration

Ketogenic diets have been used to treat epilepsy since the 1920s, and there is growing interest in their potential to treat other disorders such as cancer, diabetes, cardiovascular disease, and neurodegeneration. Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease are all characterised by disruption of the brain's energy metabolism, and so ketogenic interventions may slow disease progression or delay disease onset.

Ketones entering the brain

Ketone bodies enter the brain via monocarboxylate transporters, which are distributed throughout the brain. The uptake of ketone bodies across the blood-brain barrier is carrier-dependent and related to concentrations in the circulation. The transport capacity of ketone bodies over the blood-brain barrier is upregulated by fasting, which may also be the case in humans.

Ketone catabolism in neuronal and glial cells

Once ketone bodies have been transported into the brain, they are converted back into acetyl-CoA, which enters the tricarboxylic acid cycle for ATP generation. The conversion occurs inside the mitochondria, where beta-hydroxybutyrate is transformed into acetoacetate. Acetoacetate is then catabolised into acetoacetyl-CoA, which is then converted back into two acetyl-CoAs, ready to enter the tricarboxylic acid cycle.

Glial-neural compartment mode for ketone body supply to neurons

Glycolysis in astrocytes results in the production of lactate, which acts as an energy source for neurons. Fatty acids may also cross the blood-brain barrier, reaching astrocytes closely connected to neuronal structures. In astrocytes, degradation of fatty acids results in the release of ketone bodies to neighbouring neurons.

The effect of ketone bodies on brain metabolism

In humans, both acute and chronic increases in ketone body availability to the central nervous system cause massive changes in cerebral fuel metabolism. Acute increases in ketone availability lead to a decrease in cerebral glucose consumption, suggesting that ketone bodies can be utilised immediately as an alternative fuel to glucose. During prolonged fasting, a more pronounced shift from glucose to ketone body metabolism is reported, with ketone bodies supplying more than 50% of the brain's energy.

Ketone bodies and cognition

A number of approaches to increase ketone body availability have been applied in elderly individuals and in diseases affecting cognition. These include acute interventions of beta-hydroxybutyrate infusion or a single meal/drink of medium-chain fatty acids, and long-term treatments with continued medium-chain fatty acid supplementation.

Ketone bodies in other neurodegenerative diseases

In addition to Alzheimer's disease, ketogenic diets have been shown to have neuroprotective effects in animal models of Parkinson's disease, amyotrophic lateral sclerosis, and Huntington's disease.

Preventing brain fog: tips for reducing the risk of brain fog

Brain fog is a vague term used to describe a range of cognitive symptoms that affect an individual's mental processes. It is not a medical diagnosis but can be very disruptive to daily life. It is often associated with the keto diet, especially during the initial transition phase. Here are some tips to help reduce the risk of brain fog:

• Stay hydrated: Drink plenty of water and increase your salt intake, especially during the first week of starting a keto diet. This can help prevent dehydration and electrolyte imbalances, which are common causes of brain fog.
• Gradual transition: Instead of abruptly cutting out carbs, try a gradual transition to the keto diet. This may involve starting with a high-carb Paleo diet and slowly reducing carb intake until you find a comfortable level.
• Nutrition: Ensure you are consuming enough calories and the right balance of nutrients. Include plenty of colourful vegetables, and consider taking supplements such as magnesium and potassium to address any deficiencies.
• Sleep and exercise: Get adequate sleep and practice stress management techniques such as meditation. Exercise regularly, but avoid strenuous exercise during the initial transition to keto.
• Avoid common triggers: Identify and avoid any specific triggers that may contribute to brain fog. For example, if you are sensitive to gluten, eliminating it from your diet may help improve brain fog.
• Monitor your health: Keep track of your symptoms and how they change over time. If brain fog persists or becomes a concern, consult a healthcare professional to rule out any underlying medical conditions.

Frequently asked questions