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Coffee & Health

Can Coffee Cause Brain Fog?

What is a day without a steaming cup of coffee?

It’s not just about the stimulant that typically powers the whole body throughout the day. The combined effect of the taste and smell is incredibly soothing!

The daily coffee ritual feels good and irreplaceable until you start feeling chronic fatigue, restlessness, brain redundancy, among several other symptoms of brain fog. You begin to wonder, why? How?

coffee and brain fog

Oh my God! Could it be the coffee ritual?

Well, may and maybe not. You need to ascertain the fact before you jump to a conclusion.

The purpose of this article is to clear the coast about coffee and brain fog, guide you through how to overcome brain fog and maintain a healthy lifestyle.

Before we delve into the question of whether or not coffee can cause brain fog, a brief explanation of the term  “brain fog” is necessary.


What is Brain Fog?

Brain fog is a set of symptoms that affects the ability to think. Brain fog is not an established scientific or medical term but a common term used to describe varieties of cognitive deficiencies.

Brain fog is a cognitive dysfunction with symptoms like loss of memory, lack of concentration, haziness, and extreme fatigue. Dr. Dennis Lipton, an internist at Vail Health, described brain fog as a phrase that means the brain is not working properly.[1]

According to experts, brain fog can not be described as a disease in itself but might be a symptom of a bigger disease.[2]


With brain fog you often find yourself finding it difficult to concentrate and stay productive. You may feel confused, find it hard to think or express your thoughts in words.  Remembering things and processing information may become a herculean task.

While brain fog can be a result of a medical condition it is often associated with lifestyle


Can Coffee Cause Brain Fog?

Coffee is a brewed drink made from roasted coffee beans. People often turn to coffee to get an energy boost,  reduce physical fatigue, and stimulate mental alertness.

Despite several benefits of coffee, it also has adverse effects if consumed irresponsibly, due to its caffeine composition. Some of these effects can be directly linked to brain fog.

The chief ingredient in coffee that works the stimulating wonder is caffeine. Ironically this same ingredient is the major cause of the adverse effects of high coffee intake. According to Coffee & Health, caffeine is a major compound in coffee, a typical cup of coffee contains 75-100mg of caffeine [3]

If coffee is to be accused of causing brain fog, the culprit is caffeine.

What is caffeine and how does it affect the body?

Caffeine is a natural bitter substance found in different species of plants such as coffee, cocoa, and tea. Caffeine is a compound that works as a  stimulant for the central nervous system. A moderate intake of caffeine may enhance cognitive function and boost metabolism.

According to European Food Safety Authority (EFSA), a 75mg serving of caffeine can increase attention and stimulate alertness. Other benefits of caffeine include a lower risk of dementia and Alzheimer’s. It also reduces the tendency of suicide.


Now let’s connect the dot between  caffeine and brain fog

According to, Dr. Emily Huang, physical medicine and rehabilitation specialist in an interview with USNEWS,  ” There are numerous causes of brain fog, including sleep deprivation, poor nutritional habits, mental health issues, stress, depression, endocrine changes, lack of exercise, and dehydration.”[4]

Professor Con  Stough’s, a cognitive neuroscientist at Swinburne University, opined that lack of sleep and poor sleep quality are the biggest contributors to brain fog. [5]

While moderate consumption of caffeine can aid physical and mental performance, abuse of it can cause greater damage.

Asides from medical side effects, it is glaring that brain fog is closely related to sleep deprivation. Research has proven that sleep deprivation disrupts our brain cells. It affects their ability to communicate with each other, which leads to temporary mental dysfunction that affects memory and visual perception.

Although not everyone turns to caffeine (via coffee) to pull an all-nighter, the effect on the body system may remain the same if the level of consumption is not kept under control.

In a March 2014 Harvard Health Letter, sleep expert Dr. Lawrence Epstein, an instructor in medicine at Harvard Medical School stated that Poor sleep hurts thinking, whether it’s is due to a sleeping disorder or lack of sleep. [6]


How Caffeine Disrupts the Sleeping Pattern

Caffeine typically gains access into the bloodstream through the stomach and small intestine. Once it comes in contact with the central nervous system, it stimulates it.

As we all know,  the Central nervous system is made up of the brain, nerve, and spinal cord, caffeine typically works against the production of adenosine (a brain hormone) by the brain and conversely triggers the release of dopamine in the brain.

Dopamine is a chemical that controls, emotions, motivations, and movement. The combined effect of this activity keeps you awake, boosts your energy, and increases alertness.

Although these may lead to high productivity and aid other situations requiring increase alertness like night shifts,  it may adversely lead to sleep disturbance and deprivation especially for those who are caffeine intolerant.

As you continuously turn to caffeine for energy stimulation and alertness, you slowly drift into addiction.

This means your body has adjusted to it such that you will need to constantly increase your intake to get the desired concentration and alertness. Too much intake of caffeine may completely ruin your sleep pattern and bring about restlessness, headache, and anxiety.

You can also get sleep deprivation due to the swift action of caffeine. You can feel its effect as fast as 15minutes after consumption and it can take as long as 10 hours to get it out of your system.

Taking a high quantity of coffee in the evening will surely cut into your normal sleep time. Repeating this same circle may lead to insomnia and restlessness especially for those who are caffeine intolerant. As such, avoid taking caffeinated drinks in the evening.

Regardless of your reason for taking coffee, abuse of coffee consumption can lead to caffeine-induced brain fog. High intake of caffeine also has several other effects like diabetes, and high blood pressure.


How to Cure Brain Fog Without Giving Up on Your Cup of Coffee

Sequel to the above, you might be wondering why you have to keep up your coffee ritual despite the adverse effect it may have on your health.

Well, I advise you shouldn’t take such a decision in haste.

Consumption of coffee is not the cause of brain fog, rather the abuse of it. Despite the adverse effect of caffeine abuse, moderate consumption holds a lot of benefits that you can’t afford to miss out on. As such, we must find a way to get rid of your brain fog without discarding the coffee cup!

Shall we do that?

Let’s go!


Drink Coffee in Moderation

A 2017 review published in food and chemical toxicology recommends 400mg of caffeine per day for a healthy adult. Approximately 3-4 cups of coffee are safe for an adult. For pregnant women, NHS advises daily consumption to be cut down to 200mg daily. [7]

However, these conclusion needs to be taken with caution, as it all boils down to individual peculiarity and caffeine tolerance. You need to observe your body to know how it reacts to caffeine to decide the right quantity.

Also, take note of when you take coffee. Once ingested in the bloodstream, it may take up to 10 hours to get the caffeine out of the bloodstream. As such, it shouldn’t be taken close to bedtime.


Avoid Bad Coffee

Bad coffee is often toxic, it can cause jittery feelings and extreme fatigue.  Molds that grow on contaminated coffee beans produce mycotoxins which may lead to brain fog and other related health issues.

Research carried out on some commercial coffee showed the presence of metabolites caused by fungi- this poses great health risks.[8]

In the purchase of coffee extreme care should be taken.


Drink Plenty of Water

Staying hydrated is one of the cheapest ways of maintaining good health. Experts recommend drinking 6 to 8 glasses of fluid a day.[9]

Poor supply of water to the brain can cause numerous adverse effects, such as difficulty with focus, memory loss,  mental fatigue, and brain fog. Hydration level is one of the first things checked by neuroscientists when patients complain of brain fog-related symptoms.

Raising your hydration level can go a long way in clearing your brain fog. So when you feel some of its symptoms., increase your water intake and be intentional about it. It can help clear off the foggy feeling.



Research has shown that physical activities enhance cognitive health. Leaving the brain inactive for a long time can increase the risk of brain fog symptoms such as impaired memory,  confusion, and stress.

Exercise increases blood flow to the brain and has been proven to decrease stress, boost memory and improve sleep.

Harvard Health recommends both physical and mental exercise to abate the symptoms of brain fog[10]


See a Doctor

Lifestyle-induced brain fog is easily treated once you make reasonable adjustments. However, if the symptoms persist despite lifestyle changes consider visiting your doctor.

It might be symptoms of greater diseases. You should see your doctor if you notice your symptoms have started worsening significantly.

Brain fog can be a side effect of medical conditions and medications. It may be symptoms of depression or anxiety.



[2] diseases.

[3] caffeine.







[10] /


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