Written by Dr. Inez Van Roy on
November 23, 2021
Written by Dr. Inez Van Roy on:

Medically Reviewed by our Medical Affairs Team

You might have landed on this article because you are experiencing more mist or clouds in your head than you like. That cloudy feeling in the brain is what people refer to as brain fog. Some try to resolve this issue by changing their food choices and adding in more aerobic exercise.

If you want to achieve ketosis mental clarity (and burn fat) by eating different foods, then a keto diet might provide you with an easy guideline. 

For others, however, keto will not have a positive effect; it might be leaving you tired and weaker than before. So, keep on reading to find out what a ketogenic diet can do for you.

What is ketosis?

Ketosis is a metabolic state. Your body contains an elevated amount of ketone bodies but maintains acid-base homeostasis. This process initiates when the body can’t use glucose (or sugar) as the main source of energy.

In this case, your liver decides to use fatty acids (fat) as fuel so you can keep going. Ketone production is a source of energy by metabolizing these fatty acids, cue a high-fat diet (and the possible consequences of this way of eating). 

Your body can obtain this state by prolonged exercise, in which this activity has used up the available sugars. By fasting, there wouldn’t be any glucose available either (as there is no intake).

A low-carbohydrate diet (like the ketogenic diet) can also put your body in ‘nutritional’ ketosis.

The effects of keto are that you will most likely lose your extra body weight. Further, it is also an easy way to maintain glucose levels by eating fewer carbohydrates.

Lastly, the reason you are here—does it really improve brain fog? Read on to know more about this topic.

What is the difference between a keto diet and a low-carb diet?

The ketogenic diet drew strong attention in 1921 as a natural way to contain seizures in epileptic patients. Today, the ketogenic diet is mostly used as a fast weight loss solution. This diet is known to be a combination of a very low-carb diet while being full of fats.

They recommend keeping your carbohydrates between 5 to 10% of your total consumed calories. This boils down to about 20 to 50 grams of carbohydrates a day on a 2000 kcal diet.

The biggest portion of your caloric intake should be fat (about 55 to 60% of your daily calories). The rest should be protein. To put this in context, most starchy vegetables, grains, fruits, bread, or sweets will not be on the menu when following a ketogenic diet. 

Other low-carb diets usually don’t define the macronutrients division so clearly. You will be allowed more than 10% of carbs and will not focus on eating so many fats. There will be more freedom to function properly in your daily life. You will most likely lose weight with both diets.

Does ketosis help with focus?

Ketosis could potentially support your cognitive function. Ketone bodies pass the blood-brain barrier. This provides more adenosine triphosphate (super fuel) than glucose.

Keto could also improve cognitive function by increasing the size and efficacy of mitochondria in the brain. Mitochondria are the powerhouse for the brain cells, and as such should be protected from oxidative stress. 

Your body can keep going even with a caloric deficit during ketosis. This is because the ketone bodies keep our powerhouse in good shape and provide them with super fuel that glucose can’t provide.

Lastly, the ketone bodies also help clean up your system. They decrease free radical damage and enhance antioxidant capacity. 

What are some of the implications of a keto diet on mental performance?

For those with certain brain fog issues, the cause could be cognitive decline due to age. For example, the elderly show a pattern of reduced ability to use glucose as a source of energy in the prefrontal cortex and the hippocampus. 

Eating keto could help with brain aging by providing the energy needed to support your mental performance

In one study, rats fed on a ketosis diet seemed to increase the networks that transport ketones.

Keto also increases the vesicular GABA transporter and also decreases glutamate transporters. This resulted in an enhancement of cognitive abilities.

However, these effects are difficult to replicate with healthy and young individuals—that might be due to the ceiling level with younger participants.

Does a ketogenic diet cause brain fog?

When starting a keto diet, you most likely will go through some adverse effects. You will surely experience brain fog. You might go through what people refer to as the “keto flu.”

The keto flu comes with nausea, vomiting, headache, and fatigue. You might feel dizziness, insomnia, constipation, and too weak to exercise. These symptoms mostly reside after a few days or weeks (if you are unlucky). Just as with another flu, you should focus on drinking plenty of fluids and taking in enough electrolytes. 

As we can read, these symptoms are close to what we would describe as brain fog and a feeling of weakness.

If your symptoms don’t clear up, the diet might not be for you. If the keto diet negatively influences your cognitive performance, the possible consequences are:

  • impaired brain growth 
  • a deficiency in spatial learning 
  • and impaired memory function. 

Also, some researchers believe that people eating a low-carb diet might have more risk for malnutrition. As a consequence, your diet might not provide enough brain energy. Remember that this happens on a case-to-case basis since each individual has unique nutritional needs

Does ketosis improve brain function?

Depending on your prior state, ketogenic diets could improve brain health.

Ketosis or low-carb diets with a high-fat content could mostly benefit those with brain disorders. In animal research, we see improvement for healthy (young) animals, older rats, and sick rats. A study found better motor coordination and cognition recovery. These are results more difficult to prove for humans.

Still, for those with the following conditions, you and your doctor can go over the research together. Together you can consider if this could be part of your treatment plan.

Ketosis can improve epilepsy (fewer seizures and less severe seizures). 

Eating keto might also improve the brain health and brain function of those with Alzheimer’s disease and those with ALS (Lou Gehrig’s disease). 

Researchers point out that negative consequences of eating keto are possible. These are explained above.

What does the research say on ketosis mental clarity?

As explained above, ketosis might provide some neuroprotective properties. This is most obvious for individuals with a neurological or mental illness.

While a typical Western diet is filled with heavily processed foods and sugars. This diet could prevent brain fog by providing antioxidant effects against oxidative stress.

Still, their advantages are more than just antioxidants. There are other systems at play. Keto also bypasses the traditional way in which we produce energy for the body and brain. This theoretically could be the reason we see some of these claimed advantages.

Ketosis Mental Benefits

Research shows that ketosis can aid in cognitive function. Regarding mental health, the generalisations are more difficult to make. Most studies are done on animals and seem to be more difficult to replicate on humans.

In animals, ketogenic diets could improve resilience in the face of anxiety-inducing stimuli. We are not sure yet how ketogenic diets alleviate your anxiety symptoms.

Some researchers theorize it might have to do with its effect on the GABAergic mechanism, which plays a big role in anxiety.

Rats and mice also seem less depressed while following ketogenic eating patterns. 

Women suffering from schizophrenia might also feel a reduction in symptoms after 2 weeks of eating keto. A mouse study found similar results. However, a case study confirms that not everyone notices these improvements. 

Also, in mice and rats with ASD (autism spectrum disorder) researchers found a reduction in symptoms after eating keto. While one case study found the same response, another study with 30 children couldn’t confirm these results. 

Lastly, there is also a trial done with dogs who have ADHD and comorbid epilepsy. Symptoms for both illnesses improved after eating keto. 

While these animal studies show that eating keto can be positive, others also show that the impact on humans might be insignificant.

Concluding Thoughts

A keto diet can have a positive impact on your health. However, it also has a very high impact on your way of life. This diet needs you to keep a strict eye on what you eat. If not, it will not give you the effects you are hoping for, and there’s a probability that even if you do follow keto strictly, results are not guaranteed.

When transitioning from your regular diet to keto, you probably will experience the keto flu symptoms. You will feel sick the first days to weeks. You might feel weak and more fatigued than before. 

If you are already struggling with your mental performance, then ketosis probably won’t deliver a short-term solution. Maybe after the keto flu, you might get your desired results. You will probably consume fewer calories and food groups. This might make your cognitive performance worse due to malnutrition.

For those who do want to try this diet, there are research studies that show positive effects on our brain health. Mostly those with pre-existing conditions seem to profit from this alternative energy production.

Healthy individuals don’t seem to notice significant differences. Mild ketosis might boost brain function. You might see an increase in fat burning and have better control over your blood glucose levels. 

It is advisable to let a nutritionist or doctor set up your ketogenic plan. It will probably be low in processed foods and refined sugars. Another reason to ask for help is that this diet could also cause high cholesterol, malnutrition, dehydration, and more.

If you want to learn more about natural ways to fight brain fog and maintain mental clarity, discover more educational resources in our blog. Want to join the conversation? Let us know your opinion in our community.

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