Brain Fog: What is it? Plus Symptoms, Causes, Cures & Supplements

Brain fog is not a medically recognized term, but is a commonly used phrase that sums up feelings of confusion, forgetfulness, and a lack of focus and mental clarity.

Having brain fog is fairly common, but it’s not normal.

When you feel foggy, unfocused, and like you just can’t think, your brain is sending an important signal that there’s an issue in your life that needs to be addressed.

The causes of brain fog generally fall into one of two main categories — either it’s lifestyle-related or a side effect of a medical condition or medication.

In this article, we take an in-depth look at the eight main causes of brain fog.

And we give you specific steps to get your brain back on track quickly.

Brain Fog Cause #1: You Are Eating the Wrong Foods

One of the first things you may think when your brain gets foggy is “Was it something I ate?”

And often you’d be right.

Here are some of the many ways the food you eat could be behind your fuzzy thinking.


Refined carbohydrates like sugar and high fructose corn syrup send your blood sugar level skyrocketing up, then crashing down.

And since your brain uses glucose as its main source of fuel, this puts your brain on a roller coaster ride — first too much, then too little glucose.

Low brain glucose leads to brain fog, mood swings, irritability, tiredness, mental confusion, and impaired judgment.

Chronically high blood glucose levels lead to insulin resistance and diabetes, both of which have been linked to Alzheimer’s.

The average American consumes 156 pounds of added sugar per year.

Don’t be one of them!

Brain Fog: What is it? Plus Symptoms, Causes, Cures & Supplements

Low-Fat Diets

The low-fat diet fad has backfired, making us the fattest people who have ever walked the earth.

Your brain is largely comprised of fat, about 60% by dry weight, and low-fat diets have been as disastrous for our brains as they’ve been for our waistlines.

According to Datis Kharrazian, PhD, DHSc, author of Why Isn’t My Brain Working?, when you don’t eat enough dietary fat, the brain starts to literally digest itself for the raw materials it needs to create essential brain chemicals.

Neurologist Dr. David Perlmutter, author of the bestselling book Grain Brain, found that nothing was worse for his patients’ brains than a low-fat diet.

Glucose is usually the brain’s main fuel source, but our brains are quite happy to burn fat which he calls “super fuel” for the brain.

That’s why he recommends eating a diet roughly 50% fat from healthy sources like nuts, avocados, coconut oil, olive oil, wild salmon, eggs, and grass-fed meat.

Note that this list does not include vegetable oils like sunflower, safflower or canola oil.

Canola oil especially is high in pro-inflammatory omega-6 fatty acids which contribute to brain inflammation.

Chronic brain inflammation can be an underlying cause of brain fog, ADHD, anxiety, depression, and memory loss, as well as serious neurological diseases such as stroke and Alzheimer’s.

And you don’t need to be concerned about dietary cholesterol being bad for your brain.

Your brain contains a lot of cholesterol and too little of it increases your risk of suicide, depression, and dementia.

You read that right.

Avoiding dietary cholesterol puts your brain at risk.

Brain Fog: What is it? Plus Symptoms, Causes, Cures & Supplements

Food Allergies

Consuming foods you’re allergic or sensitive to can certainly put you in a mental fog.

The average American gets two-thirds of their calories from wheat, corn, and soy, and these are among the most common food allergies.

The other top allergy-causing foods are dairy, eggs, shellfish, peanuts, and tree nuts.

If you suspect that you react adversely to any foods you normally eat, cut them out of your diet for a week or two and notice how you feel.

Keep in mind that these foods are often lurking in processed and restaurant foods, so avoiding them is tricky. has compiled an extensive list of hidden sources of top food allergens.

Go to their food allergens page and select the food in question.

You’ll find comprehensive information on foods to avoid, plus unexpected sources.

“Wheat Brain”

Wheat is a class unto itself as a brain fog culprit.

Mayo Clinic found that celiac disease, an autoimmune disorder triggered by gluten, goes hand in hand with dementia.

But it’s not only people diagnosed with celiac disease that suffer from brain fog when they eat wheat.

According to Dr. Davis, the wheat we eat today bears little resemblance to the “the staff of life” consumed by our ancestors.

Gluten, a protein in wheat that makes dough stretchy, is considered the worst culprit, but there are over 1,000 other proteins in wheat that can trigger negative reactions as well.

Wheat has been found to worsen brain disorders like schizophrenia, autism, and ADHD.

If you decide to cut wheat out of your diet, expect to experience some unpleasant, but temporary, withdrawal symptoms.

Gluten breaks down into byproducts that bind to morphine receptors just as opiates do.

Food Additives

Anytime you eat processed food, restaurant food, or fast food, you are almost certainly getting more salt, sugar, fat, and food additives than you might think.

Two of the worst kinds of additives for your brain are MSG and artificial sweeteners.

MSG (monosodium glutamate) is a known neurotoxin found in most processed foods.

Generally the saltier the food, the more MSG it will contain, with some of the worst offenders including canned soups, salty snacks, and ramen noodles.

Alarmingly, MSG is ubiquitous yet is not required to be put on food package labels!

Innocuous-sounding ingredients like “seasoning,” “spices,” or “natural flavors” can contain hidden MSG.

When you see the words “hydrolyzed protein” or a variation thereof, that food almost certainly contains MSG.

This is common in “healthy” foods like veggie burgers.

MSG can cause brain fog and other brain-related symptoms including headaches, mood swings, dizziness, anxiety, and depression.

Another group of additives to stay away from is artificial sweeteners.

They haven’t made anyone thinner but they’ve caused a lot of other health problems.

Aspartame is made from three brain-damaging chemicals — aspartic acid, phenylalanine, and methanol.

Original studies were falsified to hide the fact that animals fed aspartame developed seizures and brain tumors, but it received FDA approval anyway.

Sucralose is no better.

It’s made from bonding sugar to chlorine, making it a toxic chlorocarbon.

Common neurological side effects besides brain fog include headaches, migraines, dizziness, anxiety, depression, and tinnitus.


Drinking enough water seems like common sense, yet 75% of Americans are thought to be chronically dehydrated.

Your brain is 75% water by volume and even mild dehydration will affect your ability to think clearly.

It takes only 2% dehydration to affect your attention, memory and other cognitive skills.

Ninety minutes of sweating can shrink the brain as much as one year of aging!

The effects of dehydration on the brain can be so noticeable that they mimic the symptoms of dementia.

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