What Causes Brain Fog? (And How to Prevent It!)

What Causes Brain Fog? (And How to Prevent It!)

Happy Spring! 

Let’s chat about one of the most prominent symptoms I have been treating in my practice over the past 3 years - brain fog. Brain fog is a common side effect of the COVID-19 virus and vaccines. Interestingly, some people suffer from it more severely than others. The question is: is it viral load or lifestyle factors that contribute to the severity of brain fog?


The most common non-viral causes of brain fog are poor sleep, low blood sugar, hormonal shifts (specifically menopause), low functioning thyroid, dysbiosis (improper gut microbiome), inflammation and dehydration. The compounded factor of COVID-19 can exacerbate these causes and really worsen symptoms. My first advice is always to look into these conditions first.


Following that, here are my tips for reducing brain fog:


  • Drink 2L of Water/Day
  • Hydration is key in maintaining a properly functioning body, especially when it comes to the brain. There are certain medical theories that correlate Alzheimer’s to dehydration. The brain is made up of over 70% water –  so the need for water is paramount. I suggest a minimum of 2L/day.


  • Reduce Alcohol Consumption
  • This is a tricky one for most, but even 1 drink at night affects sleep quality and alertness the next day. The foggy effects of alcohol on the brain are not only during consumption but affect motor function and cognition over time as well. Cutting alcohol to 1 drink/week (or zero) will positively impact brain fog.


  • Food Sensitivities
  • If your body is sensitive to a particular food and can’t digest it, sluggishness and brain fog are common side effects. Your sensitivity to foods can be determined by a blood test (requisitioned by an ND), and avoidance of those foods is recommended until reintroduction is safe.


  • Take High-quality Probiotics
  • Leaky gut is common –  and once molecules seep from the GI tract into the blood, the body shows symptoms of being unwell and brain fog is commonly seen. A strong human strain probiotic can replenish the gut microbiome which will decrease a permeable gut. My recommendation is the HMF strain by Seroyal.


  • Brain-supportive Herbs
  • There are fabulous herbs out there to sharpen acuity. My favorites are Bacopa, Lion’s Mane Mushroom, Ginkgo Biloba and Rohodiola. All can be taken individually or in various combination supplements.


    I hope this helps and is supportive in clearing the cobwebs!


    Be well,

    Dr. Kate