People often embrace keto and low-carb diets seeking improved cognition, making brain fog on keto a frustrating experience. The ketogenic diet is often expected to fix brain fog, and many individuals report enhanced mental clarity, focus, and concentration in ketosis. However, this isn't universal. In most instances, keto brain fog is a temporary issue stemming from electrolyte deficiencies (particularly sodium) or the body's adjustment to a low-carb regimen.
What is Brain Fog?
Brain fog is a subjective term encompassing various cognitive impairments. It can manifest as:
- Difficulty concentrating or focusing
- Forgetfulness
- Feeling cloudy or "off"
- Feeling slow
- Inability to think clearly
Essentially, brain fog is a mild cognitive impairment that prevents you from operating at your full mental capacity. This can affect productivity, communication skills, and mood, impacting both personal and professional aspects of life.
Causes of Brain Fog
Brain fog has numerous potential causes, and keto-related brain fog is just one possibility. Experiencing brain fog while on keto doesn't automatically mean the diet is to blame. Other potential factors include:
- Lack of sleep
- Lack of exercise
- Nutritional deficiencies
- Underlying health conditions
Poor sleep, even just one night of insufficient sleep, can significantly impair cognitive function. Similarly, a sedentary lifestyle can negatively impact cognitive performance. Certain nutrient deficiencies, particularly vitamin B12 deficiency (common in older adults due to reduced stomach acid production), can also contribute to brain fog. Various health conditions are associated with brain fog, including:
Read also: Troubleshooting Carnivore Diet Diarrhea
- Head injury
- Fibromyalgia
- Diabetes
- Allergies
- Gut dysbiosis (SIBO or candida)
The gut-brain connection is particularly relevant, as an imbalanced gut microbiome can affect cognitive health. Gut dysbiosis, including Small Intestinal Bacterial Overgrowth (SIBO) or Small Intestinal Fungal Overgrowth (SIFO, often involving Candida), can trigger brain fog.
The keto diet may help with SIBO and SIFO by restricting the food source of problematic microbes (carbohydrates). Ideally, keto should improve cognitive function, not hinder it. So, can keto both cause and cure brain fog? The answer is a conditional yes, depending on the circumstances.
Keto and Brain Fog: A Complex Relationship
Brain fog on keto typically occurs during the initial transition from a high-carb to a low-carb diet, a period that can be challenging. However, once adapted, ketosis can offer cognitive benefits. Brain fog is often the most bothersome of the "keto flu" symptoms.
Brain Adaptation Period
Most cases of keto brain fog are temporary, lasting a week or less after starting the diet. The brain, despite being only 2% of body weight, consumes 20-25% of the body's fuel, making it a demanding organ. Glucose is the brain's preferred fuel source. When glucose is readily available, the brain primarily uses it. The body has backup systems like glycogen (stored glucose) and gluconeogenesis (glucose production from non-carbohydrate sources), but these may not fully compensate for the initial glucose deficit when drastically reducing carbs.
During the initial phase of keto, glucose supply to the brain decreases, leading to reduced energy. On a keto diet, the liver produces ketones from fat, serving as an alternative fuel for the brain. However, the shift from glucose to ketones isn't instantaneous; it can take days or weeks, with longer transition periods for those starting from higher-carb diets.
Read also: Restore your metabolism with reverse dieting
The remedy: Time. Usually, the brain fog resolves within a week or so of consistent keto dieting. This is related to insulin levels. When carb intake is restricted, insulin levels remain low and the kidneys release excess sodium. A whole-food keto diet is naturally low in salt (sodium chloride).
It's important to avoid panic if brain fog occurs during the first week of keto. It's often a normal, temporary symptom. If it persists, hydration issues should be considered. Adequate electrolyte intake, especially sodium and potassium, along with sufficient fluids, is crucial to replace what's lost on keto.
Once keto-adapted and properly hydrated, brain fog should subside, potentially leading to cognitive enhancement.
The Keto Flu: A Broader Perspective
The transition to a ketogenic diet (keto-induction) can trigger transient symptoms known as the "keto flu," which may deter continued adherence. Common symptoms include:
- Nausea
- Emesis (vomiting)
- Reduced appetite
- Hypoglycemia (low blood sugar)
- Acidosis
- Increased risk of kidney stones
- Altered liver biochemistry
- Skin rash
These symptoms typically appear within 2-3 days of starting a keto diet and usually resolve within 2-4 weeks. Approaches to reduce these symptoms include avoiding fasted initiation and supplementing with medium-chain triglycerides (MCT) and ketone salts.
Read also: Optimize your stationary bike routine
A ketogenic diet (KD) involves very low carbohydrate intake, moderate protein intake, and higher fat intake to maintain energy balance. This promotes fatty acid oxidation over glucose oxidation, mimicking a starvation state and increasing ketogenesis in the liver. Ketone bodies (β-hydroxybutyrate (βHB), acetoacetate (AcAc), and acetone) become alternative fuel substrates. The blood-brain barrier is permeable to ketone bodies, allowing them to cover up to 70% of the brain's energy needs when glucose is limited.
Nutritional ketosis (NK) is a physiological adaptation to low carbohydrate availability and differs from the pathological state of ketoacidosis, which results from metabolic dysregulation in conditions like alcoholism and uncontrolled type 1 diabetes. KDs are being studied for treating metabolic disorders like obesity, type 2 diabetes, cardiovascular disease, cancer, and dementia. They have been used for over a century to treat intractable epilepsy.
A classical KD typically has a macronutrient mass ratio of 4:1 (fat to non-fat), and a carbohydrate intake limit of 50g per day is commonly used to induce ketosis. Research suggests promising neuroprotective effects of KDs, potentially benefiting Alzheimer's disease, Parkinson's disease, multiple sclerosis, Huntington's disease, autism spectrum disorder, stroke, motor neuron disease, malignant glioma, migraine headache, and traumatic brain injury. KDs can also improve weight loss and insulin sensitivity in obesity, type 2 diabetes, and polycystic ovary syndrome.
Ketone bodies may also regulate the nervous system. They act as ligands for G protein-coupled receptors, influencing cellular responses and signaling in lipid metabolism and cellular growth pathways. Additionally, ketone bodies can regulate neuronal excitability by decreasing neuronal firing, increasing GABA synthesis, and reducing glutamate release. They can also exert neuroprotection via autophagy upregulation, cerebral blood flow stimulation, epigenetic regulation, and anti-inflammatory effects.
Clinical applications of KDs extend to autosomal dominant polycystic kidney disease (ADPKD) and cancer. In ADPKD, lowering glucose availability via a KD may combat cyst development. In cancer research, there's renewed interest in targeting the Warburg effect, where cancer cells upregulate anaerobic glycolysis even with sufficient oxygen. The KD is being explored as a means of restricting tumor glucose supply, with research also focusing on the role of ketone bodies in epigenetic alterations in tumor cells and the effect of lowered insulin levels on oncogenic signaling pathways.
A potential obstacle to adopting a KD is the experience of adverse symptoms in the first few weeks, the "keto-flu." Documenting and understanding these symptoms and their mechanisms can help prevent or relieve these temporary side effects.
Specific Keto-Flu Symptoms and Their Duration
Reported symptoms of "keto-flu" include:
- Headache
- Lightheadedness
- Fatigue
- Lethargy
- "Brain fog"
- Decreased exercise capacity
- Mood changes
- Constipation
- Muscle cramps
- Diarrhea
- Halitosis (bad breath)
Other reported symptoms include nausea, emesis, hypoglycemia, acidosis, kidney stones, and skin rash.
Halitosis: Experienced by 38% of people on a KD compared to 8% on a low-fat diet.
Gastrointestinal Issues: Constipation is reported in 15-63% of the pediatric population and is a common side effect in adults. Nausea (27-42%) and vomiting (5-36%) are also common in children. Diarrhea is reported in some studies involving children (3.6-20%) and adults (2%).
Decreased Energy: Fatigue, weakness, asthenia, or lethargy are reported in 17-28% of children and 18% of adults.
Light-headedness and Dizziness: Relatively common in adults (15-21%) but not reported in pediatric studies.
Headache: Relatively frequent in adults (8-25%) but not reported in the pediatric literature. Fussiness is reported in pediatric studies (6%).
"Brain Fog": Reduced cognitive performance reported in 10% of healthy adults and described as a "common symptom" by others.
Reduced Exercise Performance: Impairment seems to last 3-4 weeks, with a return to normal exercise capacity and performance upon "keto-adaptation."
Mood Changes: Irritability reported in pediatric patients (6.7-10%). Studies show improvements in mood from the start to the finish of the diet, although some studies report lower energy levels during keto-initiation.
Practical Strategies to Minimize Keto Brain Fog
- Ease into the Diet: Gradually reduce carb intake instead of making drastic changes abruptly. Start with a typical low-carb diet and allow the body time to adjust.
- Hydration is Key: Drink plenty of water to combat headaches and boost energy levels. Determine your minimum daily water intake by dividing your body weight (in pounds) by two to get the number of ounces needed.
- Electrolyte Replenishment: Add electrolytes like salts, potassium, and magnesium to your diet to prevent cramps and nausea. Keto diets can deplete electrolytes due to the restriction of electrolyte-rich foods.
- Adequate Fat Intake: Ensure sufficient intake of healthy fats, as low calories can exacerbate keto flu symptoms. Avoid simultaneously reducing both carbs and fats. Increasing fat consumption can accelerate the transition to fat-burning for fuel.
- Prioritize Sleep: If experiencing difficulty sleeping, consider an Epsom salt bath to relax muscles and improve electrolyte absorption. A keto-friendly herbal tea can also promote deeper sleep.
- Light Exercise: Engage in light exercise to relieve muscle pain and tension.
- Consider Exogenous Ketones: Supplementing with exogenous ketones can provide an immediate source of energy for the brain during the adaptation period.
Addressing Underlying Causes
It's crucial to identify and address any underlying causes of brain fog, such as:
- Nutritional Deficiencies: Ensure adequate intake of essential nutrients, especially B vitamins.
- Sleep Deprivation: Prioritize sleep hygiene and address any sleep disorders.
- Stress Management: Implement stress-reduction techniques like meditation or yoga.
- Gut Health: Support gut health through diet and, if necessary, address any gut dysbiosis issues.
The Broader Context of Ketogenic Diets
Ketogenic diets can be useful for short-term goals like weight loss or temporary metabolic resets. However, it's important to remember that the brain still needs glucose. Instead of drastically cutting carbs, focus on smarter carb choices.
Transitioning from a standard American diet, rich in simple carbs, trans fats, and saturated fat, is a big change in how cells use energy. There is no need to go online and buy any expensive supplements. Despite its name, this is not like the flu. You will not develop a fever and the symptoms can hardly ever make you incapacitated. Make sure you drink plenty of water. Eat more often and make sure you have plenty of colorful vegetables.
Benefits of Keto Beyond Brain Fog
- Weight Loss: Reducing carbohydrate intake can aid in weight loss, especially in the initial weeks.
- Blood Sugar Control: Keto can lead to fewer and less severe blood glucose fluctuations.
- Elimination of Processed Foods: Going keto often involves eliminating processed foods containing sugar, gluten, artificial sweeteners, and other potentially harmful ingredients.