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The True Brain Fog Diet Based on Science

By Liam McAuliffe Updated on

Brain fog is tough to define, but we all know what it feels like. Those times when it’s harder than usual to accomplish even simple cognitive tasks. When we forget obvious details like appointment times and the names of people we’ve met before. When we generally have a hard time focusing and expressing ourselves. The brain fog diet is aimed at eliminating the dietary causes of brain fog and supporting mental clarity and cognitive power through food choices. 

Though brain fog is not an official medical condition, there is ample evidence that our diets have a lot to do with these symptoms. Some of the factors that link diet to brain fog include nutrient deficiencies and inflammation caused by chronically high blood sugar and plant toxins. 

In this article, we’ll take a deep dive into what causes brain fog and offer a detailed approach to an effective brain fog diet. 

Table of Contents

What is Brain Fog?

Brain “fog” isn’t just one thing. It’s a collection of symptoms that impair your ability to think clearly and effectively.

These annoying and even debilitating symptoms can make it hard to concentrate, to transition between tasks, and can impair both short and long-term memory.

Brain “fog” is common among people who have autism spectrum disorders (ASDs), celiac disease, chronic fatigue syndrome, fibromyalgia, mastocytosis (that abnormal growth of immune cells), and who are showing early signs of Alzheimer’s disease (AD) and other neuropsychiatric disorders.

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Symptoms of Brain Fog

The most common symptoms of brain fog, include

  • Difficulty focusing
  • Lapses in concentration
  • Confusion
  • Forgetfulness/Absentmindedness
  • Slow processing of information 
  • Struggling to put your thoughts into words
  • Mood swings

What Causes Brain Fog?

Researchers believe that brain fog is often caused by inflammatory molecules, including cytokines and histamine released from mast cells that cause chronic, brain-specific inflammation.

So, to formulate a true brain fog diet, we have to get clear about what dietary factors contribute to chronic inflammation. 

High Blood Sugar

The standard American diet is loaded with high-carb foods, including grains and added sugars. 

Constant consumption of high carb foods causes your blood sugar to spike and remain at high levels. Chronically high blood sugar leads to system-wide chronic inflammatory response.

Chronic inflammation in the brain imbalances important neurotransmitters like serotonin and can damage brain and nerve cells. All of which contribute to cognitive problems associated with brain fog. 

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Plant Toxins That Cause Brain Fog

Many common plant foods, including legumes, grains, leafy greens, and many fruits contain plant toxins and antinutrients that can contribute to brain fog by causing allergic/inflammatory responses and by impairing the absorption of brain-specific nutrients. 

Some of the most common plant toxins and antinutrients associated with brain fog include

  • phytates (phytic acid) found mostly in legumes and grains. Binds to dietary zinc and iron, causing deficiencies that can impair cognition.
  • Lectinsin legumes, grains, and nightshade vegetables. Studies have found that lectins exacerbate inflammation associated with IBS and autoimmune conditions.
  • Oxalates can cause systemic inflammation and have even been found to build up in small blood vessels in the brain.

What is the Brain Fog Diet? 

With the factors that cause brain fog in mind, let’s turn to what constitutes a true brain food diet. 

Nutrient Dense Foods

The foods that reduce brain fog and promote mental clarity will be loaded with true brain foods that provide a full spectrum of brain-specific nutrients and free from excess carbs and plant toxins. 

News flash: these are not grains, leafy greens, and berries. All of which are high in carbs and toxins, and remarkably low in important nutrients when compared to animal-based whole foods. 

The cornerstone of the brain fog includes the following nutrient-dense foods

Fresh Ruminant Meat From Beef, Bison, and Lamb

Meats from ruminant animals are the most nutritionally complete foods on earth, making them the center of the brain fog diet. 

Red meat, especially from grass-fed animals, is high in anti-inflammatory conjugated linoleic acid

Studies have found that CLA  “exerts profound anti-inflammatory effects”. [23 

A study on 23 young men who consumed 5.6 grams of CLA daily found that it significantly reduced inflammatory markers. [24]  

Red ruminant meats are also an unsurpassable source of B vitamins, including remarkably high levels of B12

B12, B3, folic acid, and B6 have been found to prevent mental decline and prevent depression and other psychiatric disorders. [11] [12] [13] [14] [15]

Red meat is also a robust source of selenium. This compound offers antioxidant protection that has been shown to reverse cognitive damage caused by stroke. Selenium is also associated with increases in learning ability and memory in aging brains. [25] [26]

A French study from 2018 looked at the impact that giving up various food groups had on the depressive symptoms of 90,000 people. 

The researchers found that incidences of depression increased as participants gave up red meat, poultry, fish, and dairy. The people who had given up at least three of four animal-based food groups were at a 250% increased risk of depression. [21]

Brain fog isn’t depression, but many of the symptoms overlap. The same animal nutrients that prevent depression likely reduce brain fog. 

Let’s get specific and look, for example, at the abundance of brain-specific nutrients provided by a single cut of ribeye steak. 

Brain Fog Busting NutrientsAmount Per 227 grams (8 oz)
Protein65 grams
Fat24 grams
Omega 3 fatty acids64 mg
Vitamin D 14 mcg (70%)
Vitamin B123.4 mcg (142%)
Vitamin B617 mg (100%)
Vitamin B3 (Niacin)19 mg (119%)
Vitamin B1 (Thiamin.3 mg (25%)
Folate (B9)26 mcg (7%)
Riboflavin.3 mg (23%)
Choline170 mg (31%)
Iron5 mg (68%)
Selenium72 mcg (131%)
Zinc12.2 mg (111%)
Copper.3 mg (33%)


Being called an “egghead” means you’re really smart, and that’s not a coincidence. 

Eggs are loaded with choline and lecithin. These two compounds are the building blocks for the neurotransmitter acetylcholine, which is directly linked to better learning and memory. [30]

Eggs are also a fantastic source of the underrated vitamin K2. This essential nutrient has been found to reduce inflammation, support mood and overall brain health, and may reverse age-related cognitive decline. [20] [21] [22]

The yolks of only two eggs from pasture-raised hens provide around 120 mcg of K2, accounting for a full 100% of your recommended daily intake. 

To get the most brain-fog-busting power from your eggs, choose pasture-raised eggs, eat the yolk, and cook them in ways that preserve their nutrients. 

Brain Fog Busting NutrientsAmount Per 100 grams (2 eggs)
Protein12 grams
Fat10 grams
Vitamin D (pasture-raised eggs)63%-500% if fortified
Vitamin K 120 mcg (100%)
Vitamin B122.7 mcg (108%)
Folate 47 mcg (24%) 
Choline285 mg (71%) 
Iodine 50 mcg (34%)
Selenium23 mcg (42%)

Seafood: Fatty Fish and Shellfish

Fish, especially fatty fish like wild salmon, arctic char, sardines, mackerel, and anchovies, are excellent brain fog diet foods thanks to their combination of complete proteins and essential Omega-3 fatty acids. 

A 2022 meta-analysis of nine studies with over 1300 participants found that ingestion of omega-3 fatty acids increases learning, memory, cognitive well-being, and blood flow in the brain.6

Let’s look at some of the nutrients in wild king salmon that make it a great addition to your brain fog diet. 

Brain Fog Busting NutrientsAmount per 100 grams. 
Omega-3 fatty acids780-1800 mg (120-300%)
Vitamin B12 7.4µg (308%)
B38.4mg (53%)
B6.3mg (21%)
B51gm (21%)
Vitamin A453.0IU (15%)
B1.2mg (13%)
B2.2mg (13%)
Vitamin D 526-1200 iu (66-160%)
Vitamin E1.5mg (10%)
Selenium31.0µg (56%)
Potassium 370.0mg (10%)

In addition to fatty fish, shellfish make for remarkably brain-healthy seafood choices. 

Oysters provide more zinc than any other food. Studies have found that zinc reduces oxidative stress and inflammation associated with neurodegeneration. [16]

Mussels provide more brain-boosting B12 than any other food. 

Together, these shellfish provide a powerful complex of zinc, copper, vitamin D, vitamin B12, and selenium. All of these nutrients provide antioxidant protection against oxidative stress and inflammation, specifically in the brain. [31] [32]

Here’s a rundown of the brain fog diet nutrients provided by around six oysters. 

Brain Fog Busting NutrientsAmount Per 100 grams 
Protein7 grams
Fat2.5 grams
Vitamin D 320 iu (80%)
Vitamin B1219.5 mcg (324%)
Iron4.9 mg (62%)
Selenium63.7 mcg (91%)
Zinc90.8 mg (605%)
Copper4.5 mg (223%)

Full-fat Dairy Products and Ripened Cheeses

Numerous studies have found that cheese intake is associated with improvements in cognitive functioning and protection against age-related cognitive decline. 

So, if you can tolerate dairy, you’d be wise to make cheese part of your brain fog diet. 

A major study 2020 study published in the Journal of Alzheimer’s Disease, looked at data from 1,787 people between the ages of 46 and 77. The goal was to identify the dietary changes that would best prevent age-related cognitive decline. According to the data, cheese was by far the most cognitive protective food. [35]

One Dutch study found that a 30 g increase in Dutch cheese consumption was associated with a 33% lower probability of poor information processing speed. 8

A 2023 study published in the journal Nutrients found that among Japanese people over 65, regular cheese consumption is associated with better cognitive function. 9 

The many studied cognitive benefits of cheese are likely due to multiple factors, including the high vitamin k2 in many varieties, and the beneficial bioactive peptides formed in the ripening process. 

Blue cheese, in particular, has been found to provide between 2900 and 4700 different bioactive compounds [33] [34]

Indeed, a 2018 study on blue cheese found that its bioactive compounds offered protection against neurodegenerative disorders. [36]

One of the most powerful compounds in ripened cheeses is called spermidine. This compound has been shown to reduce inflammation, enhance the formation of memory cells, and stimulate autophagy– a process that removes and recycles damaged organelles and proteins in cells. This process reduces the risk of neurodegeneration, dementia, Parkinson’s, and Alzheimer’s.”[38] [39] [40] [41] [42] [43]

Let’s take a look at some of the cognition-boosting nutrients in blue cheese. 

Brain Fog Busting NutrientsAmount Per 100 grams
Protein 13.3 g
Fat43.3 g
Omega 3 fatty acids75 mg
Vitamin B51.7 mg (35%)
Vitamin B20.4mg (36%)
Selenium8.6µg (16%)
vitamin K236 mcg (30%)
Spermidine262 nmol/g

Low Carb and Low Toxin Fruits and Veggies

The animal-based foods above are the centerpiece of any true brain fog diet. Fruits and veggies simply do not compare when it comes to providing brain-specific nutrients. 

That said, fruits and veggies can provide variety and familiarity. To avoid plant toxins and antinutrients, a rule of thumb is to focus on roots and fruits, AKA berries and tubers. 

The True Brain Fog Diet: The Bottom Line

A true brain fog diet must center on foods that reduce inflammation while providing an abundance of brain-specific nutrients. These foods all happen to be from animal sources and not from the plant foods that many mainstream nutritional institutes promote. 

In fact, a recent study on the MIND diet (Mediterranean-DASH Intervention for Neurodegenerative Delay), essentially a plant-based version of the Mediterranean diet, failed to do any better than a control diet of mild caloric restriction on numerous outcomes, including cognition and hippocampal volumes.8

This is only surprising if you buy into plant-based dogma and actively ignore the significant, easily accessible findings published in mainstream journals confirming the cognitive protection and enhancement associated with nutrient-dense animal products. 

In short, a diet that has the greatest chance of burning away your brain fog is centered around ruminant meats, eggs, seafood, and full-fat dairy. At the same time, it eliminates all processed foods, including grains, added sugars, and seed oils. 

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