Why Does the Keto Diet Cause Brain Fog?

Over the past few years, the trendy ketogenic diet (keto for short) has been adopted by celebrities and health junkies alike. 

Not only has keto been linked to weight loss, but scientists have even suggested that a keto diet might boost brain function and serve as a possible treatment for Alzheimer’s disease. 

But embracing a keto lifestyle doesn’t come without a few drawbacks — and not just saying bye-bye to bread, either. Learn the possible side effects of a Keto diet and how they might lead to the keto flu or brain fog. 

The keto diet is characterized by its low carbohydrate and high fat content. It comes with a laundry list of potential health benefits, including weight loss and lower blood-sugar levels. 

What sets the keto diet apart from others is that it increases levels of ketones in the blood, a state known as ketosis. The metabolic effects of a ketogenic diet are similar to those experienced during starvation. 

When the body is deprived of glucose, the liver begins producing ketone bodies. Ketone bodies can cross the blood-brain barrier and are used by both neuronal and glial cells in the brain as a source of energy. By using fat as the primary energy source, the body increases its fat-burning capacity, which is why the keto diet is often associated with weight loss.

Ketone bodies can have an appetite-suppressing effect. Many people on a ketogenic diet report feeling less hungry and experience fewer cravings, which can lead to a reduction in caloric intake and further weight loss.

Read More: How Do Low-Carb Diets Work for Weight Loss?

The ketogenic diet, while beneficial for weight loss and other health conditions, can also have several side effects, especially during the initial phase as the body adjusts. Common side effects include:

• Lethargy

• Dehydration

• Acidosis

• Changes in behavior

• An increase in infections

• Constipation

• Vomiting

• Keto flu

Read More: How to Tell If Your Body Is In Ketosis

You may experience a cluster of side effects within the first few weeks of starting a ketogenic diet. These are frequently referred to as the ”keto flu.”

Keto flu symptoms typically vary but they may consist of:

• Fatigue and weakness: due to the body adjusting to burning fat for energy instead of carbohydrates

• Headaches and dizziness: possibly related to dehydration and electrolyte imbalances

• Irritability and mood swings: often attributed to sugar and carbohydrate withdrawal

• Muscle cramps and soreness: linked to electrolyte imbalances, particularly low levels of magnesium, potassium, and sodium

• Digestive issues: including constipation or diarrhea, as the body adjusts to a different dietary composition

• Insomnia and poor sleep quality: temporary disruption of sleep patterns during dietary transition

• Brain fog: likely due to changes in energy sources for the brain

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“Brain fog” is a term used to describe a range of cognitive symptoms that affect an individual's mental processes. It refers to mental fatigue, hazy thinking, and difficulty with concentration and memory but it is not considered an official medical diagnosis. It is used to articulate a feeling of mental cloudiness or lack of clarity. 

While there has been little research on what, exactly, causes keto flu and brain fog, the symptoms might be the body’s response to carb withdrawal. Typically, keto practitioners report that the symptoms are short-lived, and last only a few days as they transition away from carb-centric foods. 

Read More: In a World of Endless Choices, Why Is Decision-Making So Tiring?

When experiencing brain fog, you might notice various changes in your daily mental functions. These can manifest in several ways, affecting everything from your memory to your ability to concentrate. Here are some common signs that you might be facing such difficulties:

• Distractions seem to disrupt your focus more easily.

• Sometimes, you might feel as though you're in a dreamlike or trance state.

• You occasionally enter a room and forget the purpose of your visit.

• Multitasking poses a challenge for you.

• Often, you find yourself unable to recall the right words at the right moment.

• Remembering specifics from conversations can be difficult.

• Understanding new concepts or learning seems harder than it used to be.

• Absorbing new information isn't as easy as it once was.

Read More: 4 Things You Should Know About Cognitive Dissonance

Things like drinking plenty of water and increasing salt intake, while avoiding too much strenuous exercise, might help treat brain fog. Other ways to get rid of brain fog may include:

• Eat smaller, more frequent meals.

• Incorporate a variety of colorful vegetables into your diet.

• Think about gradually transitioning into the new diet.

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Brain fog manifests as a sense of mental confusion or lack of mental clarity. Common symptoms include difficulty concentrating, forgetfulness, a sense of mental fatigue, trouble processing information, and struggling to articulate thoughts. People often describe it as feeling "cloudy" or as if their thoughts are sluggish and not as sharp as usual.

Treatment for brain fog involves addressing the underlying cause. General strategies include improving sleep quality, managing stress, regular physical exercise, staying hydrated, and ensuring a balanced diet rich in nutrients. Cognitive exercises and mindfulness practices can also help. If brain fog persists, it's advisable to consult a healthcare professional to rule out any medical conditions.

The duration of brain fog varies depending on its cause. In many cases, it can be temporary, resolving with adequate rest or lifestyle changes. However, if it's linked to a medical condition or chronic stress, it might persist longer and require targeted treatment.

Yes, anxiety can lead to brain fog. Anxiety can disrupt cognitive functions, making it difficult to concentrate and process information. The mental exhaustion from chronic anxiety can also contribute to a foggy feeling in the brain.

Allergies can indeed cause brain fog. Allergic reactions often lead to inflammation and release of histamines, which can affect cognitive functions and lead to symptoms of brain fog. Additionally, the fatigue associated with allergic reactions can exacerbate this effect.

Stress is a common cause of brain fog. Chronic stress can impair cognitive functions, disrupt sleep, and lead to mental exhaustion, all of which contribute to the experience of brain fog. Managing stress through relaxation techniques and other stress-reduction strategies can be helpful in alleviating these symptoms.

Read More: Keto Diet Helps Fight the Flu in Mice, Study Shows

This article was originally published on Dec. 21, 2019 and has since been updated by the Discover staff with new information.