Part 1: What Causes Brain Fog?

Nowadays, many diet and lifestyle factors can cause brain fog (the obscure brain lag that keeps you from being your most creative and productive). Without addressing the root causes, you may have found that some stimulants or nootropics can make brain fog worse.
Fact checked by Nattha Wannissorn

Brain fog reflects that your brain may not be healthy enough to function at its best. To address it, you need to take into account all of the reasons brain fog exists. Also, each case of brain fog is different, which is why we ensure that our stacks are personalized.

This article, part 1, will cover the different contributors to brain fog. In the next article, part 2, we will cover how Nootopia’s personalized nootropics can eliminate brain fog and catapult you into your apex performance.

Contributors To Brain Fog

man sitting with his hands over his head

To put an end to brain fog, you first have to know what causes it. Your brain needs appropriate nutrients, optimal brain metabolism, and healthy neurotransmitter levels. 

In addition, to function at a high level consistently, you need to keep inflammation and oxidative stress in check. Keep in mind that brain fog can also be a symptom of more severe conditions, so you want to consult your medical provider to rule these out first. 

Many people still feel brain fog despite being deemed healthy. While brain fog is very common, we believe that it’s far from healthy. The following are the primary contributors to brain fog and are areas that Nootopia addresses.

Low Acetylcholine

Acetylcholine (ACh) is a foundational neurotransmitter for memory, focus, and more. Outside the brain and central nervous system, ACh is the primary stimulating/excitatory neurotransmitter. However, in the brain, ACh functions more as a neuromodulator. The primary functions of ACh in the brain are:

  • Alters how sensitive or excitable neurons are to other signals
  • Modulates the release of other neurotransmitters 
  • Coordinates the collective firing of groups of neurons 

Neurons that release ACh are found throughout the entire central nervous system, affecting all areas of the brain. Healthy ACh function is particularly important for learning, memory, and attention, making it a primary target to get rid of brain fog. 

Low acetylcholine may also affect the vagus nerve, contributing to whole-body inflammation.


Neuroinflammation is inflammation present anywhere in the central nervous system (brain and spinal cord). As with inflammation in the rest of the body, it’s normal and natural to have some low and temporary inflammation in your brain. 

Chronic neuroinflammation however, is particularly detrimental to brain health and function. Brain fog is one symptom of neuroinflammation, due largely to the downstream effects of elevated immune system messengers (cytokines). 

Neuroinflammation chart
Source: Neuroinflammation: The Devil is in the Details

Other common manifestations of neuroinflammation include:

  • Damage to cells in and around the area of
    inflammation. Whatever function these neurons 

    carry out is then compromised.

  • Anxiety
  • Depression
  • Cognitive impairment
  • Decreased neural plasticity, or the ability of your nervous system to adapt and change in response to internal or external factors

Neuroinflammation can be caused by a single or a constellation of factors including:

  • Chronic stress
  • Emotional trauma
  • Physical trauma, such as head injury
  • Infection, both inside and outside the brain
  • Exposure to certain environmental toxins, like heavy metals
  • Mold exposure/mycotoxins
  • Normal aging
  • Leaky gut
  • Leaky blood brain barrier

Leaky Blood Brain Barrier

The blood-brain barrier (BBB) is the barrier between your bloodstream and your brain. It is a primary control point for determining what enters the brain and what is excluded. The BBB is very selective about what gets across. A healthy BBB has receptors to allow certain molecules to cross. Very small substances and fat soluble molecules typically will make it across the barrier as well.  

blood brain barrier

If the BBB becomes leaky, substances that would normally be excluded from entering the brain can cross. Other molecules that would have crossed in a controlled manner are now able to flood in as well. It is a lot like leaky gut, only of the brain.

Leaky BBB results in a host of neurologic dysfunctions and neuroinflammation. Inflammation increases BBB permeability, which increases neuroinflammation, which further increases leaky BBB. This creates a cycle of dysfunction.

Symptoms and health conditions associated with leaky BBB include:

  • Brain fog
  • Depression 
  • Neurodegenerative diseases (Alzheimer’s, Multiple sclerosis, etc.) 
  • Autism
  • Seizures 
  • Schizophrenia 

While researchers have uncovered many BBB breachers, they’re still trying to understand the exact processes. All of these factors are associated with leaky BBB and may contribute to its development.

  • Systemic (whole-body) inflammation
  • Heavy metal toxicity
  • Leaky gut 
  • Sleep-wake cycle disruption
  • Stress
  • Bacterial infection
  • High homocysteine levels
  • Blood sugar imbalance/hyperglycemia
  • Mold toxins (mycotoxins)

Low Brain Metabolism Or Poor Mitochondrial Function

When your brain cells don’t produce enough energy, it becomes difficult to think clearly and focus. Low brain metabolism causes poor mental performance and brain fog. 

Some reasons for low brain metabolism include:

  • Decreased cerebral blood flow
  • Insulin resistance
  • Mitochondrial dysfunction
  • Low thyroid function
  • Hypoxia or low oxygen delivery to the brain, such as in sleep apnea or anemia

The metabolic pathways of brain cells also need adequate cofactors in order to produce enough energy. Some cofactors required for cellular energy production are B vitamins, CoQ10, and Alpha-lipoic acid (ALA).

High Oxidative Stress

Along with inflammation, oxidative stress is most likely the cause of brain fog.  Brain cells are particularly susceptible to oxidative stress because of their high oxygen use. Oxidative stress may be caused by other factors, such as leaky BBB and inflammation. However, most of the contributors to brain fog end up resulting in increased oxidative burden on the brain.

Oxidative stress damages mitochondria and triggers inflammation pathways. The lipid membranes of neurons can be damaged by oxidative stress as well. This causes cell dysfunction and potentially cell death. 

Oxidative stress can cause the mitochondria to slow down to protect your cells from more oxidative stress. It’s natural to have high oxidative stress at night in order to sleep. However, other persistent lifestyle-related oxidative stress can cause daytime fatigue and the “cloudy head” sensation common in brain fog.


Your brain needs some stress as stimuli to stay alive and grow. However, the inability to enter a parasympathetic state or constant stress reactivity can cause brain fog. 

Chronic, unmanaged stress leads to poor brain function all around. These may include emotional, social, and cognitive functioning. Stress decreases the capability of neurons to send signals appropriately. What’s worse is that stress causes a loss of neurons and can actually cause the brain to shrink. 

woman stressed full of tasks

Chronic stress and trauma can cause chronic activation of the sympathetic nervous system (fight or flight) and the hypothalamic-pituitary-adrenal (HPA) axis. This decreases cerebral blood flow to crucial areas of cognitive function such as the hippocampus. It can even cause the wrong kind of brain rewiring towards more stress reactivity.

Men are particularly vulnerable to memory impairment from chronic stress due to changes in the hypothalamus.

Nutrient Deficiencies 

Besides the vitamins and minerals that support mitochondrial function, there are other vital nutrients necessary for healthy brain function and eliminating brain fog. These are some of the most important nutrients for brain health.

Omega-3 Fatty Acids

The brain is made up of nearly 60% lipids (fats). Omega-3 essential fatty acids (EFA) provide healthy structure to neurons and keep cell membranes healthy and fluid. EFA’s also act as cell messengers and are involved in the production of neurotransmitters.

Omega-3’s may improve brain fog, including attention and memory.  

Healthy levels of omega-3 fatty acids are neuroprotective.


Magnesium is a cofactor in metabolic and neurotransmitter functions in the brain. Low or suboptimal magnesium levels are associated with poor cognitive performance.  People with higher magnesium levels have better attention and memory performance, and less likelihood of developing cognitive impairment.

Low magnesium levels may also predispose anxiety, depression, and decreased stress resilience. These each negatively impact cognition and contribute to brain fog.   

Vitamin B12

Vitamin B12 plays an irreplaceable role in the nervous system. As a vitamin cofactor, B12 is required for the production of the myelin sheath around nerves. This makes nerve conduction efficient and effective.

Low B12 manifests as a number of potentially irreversible nervous system symptoms, including:

  • Cognitive impairment
  • Numbness and tingling in extremities
  • Headaches
  • Tinnitus (ringing in the ears)

Vitamin D

Vitamin D promotes cognitive function, including learning and memory.

Low vitamin D levels can affect mood, and mood changes are associated with brain fog. Mood stabilization may be a primary means that vitamin D supports cognitive performance.  

Poor Sleep Or Lack Of Sleep

Everyone has experienced the way the brain functions on little or poor quality sleep. Sleep deprivation increases the risk for chronic disease. It causes brain dysfunction that results in impaired decision-making and increased risk for motor vehicle accidents.

Inadequate sleep impairs the signaling between neurons and leads to momentary “cognitive lapses.” These lapses impact memory and visual perception.

tearing a sheet with sleep wrote on it

Too Much Of The Wrong Stimulants 

Stimulants, such as caffeine, can have various effects from person to person. Your genetics have a lot to do with this. Some people can process and metabolize stimulants relatively efficiently, while others are poor metabolizers. 

If you have genetics that keep you from processing and eliminating stimulants well, they tend to cause jitters that inhibit cognitive function. This is why some people are sensitive to even small amounts of coffee, for example.

For these folks, too much stimulants may actually cause brain fog. Caffeine and other stimulants are also vasoconstricting and may decrease cerebral blood flow.


Brain fog is not a nootropic deficiency. To successfully eliminate brain fog and enable your brain to function in all cylinders, most people need a comprehensive approach that goes beyond conventional nootropics. Also, every case of brain fog is different, so a one-size fits all approach can work great for one person and worsen brain fog for another. 

Try our quiz here to find out what stack works best for you.

In our next article, part 2, we’ll cover how Nootopia’s personalized nootropic stacks uniquely help with brain fog.


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