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Lifting the fog

By Rory Linehan

 Key Messages:

  • Brain fog is difficult to describe because little is known about its cause and there are a range of symptoms associated with it
  • Commonly it presents as reduced cognition, an inability to focus and a loss of memory
  • It is often correlated with chronic illness such as autoimmune disease
  • There are many theories behind its cause. A theory which is gaining increasing traction is the breakdown of the Blood-Brain-Barrier causing brain inflammation
  • I overcame brain fog and you can too

Brain fog …. It’s a term that’s used often in the functional medicine community and increasingly in the general medical community, but its meaning, like the condition itself, isn’t always very clear.

That’s because how one person experiences brain fog is often very different from another, it’s pathogenesis (cause) isn’t clear and for those with brain fog, impaired cognition means that just describing the condition can be a challenge unto itself.

In this two-part post, I’m clearing the skies and simplifying brain fog. I’ll break it down, explain what it is, how it happens, my experience with it and above all, what you can do to heal from it.

Breaking down brain fog

According to Lawrence Wilson MD, brain fog is a “feeling of mental confusion or lack of mental clarity”[1]. It may present as reduced cognition, an inability to focus, dizziness and/or as a loss of memory[2]. It is referred brain fog because it can feel like the person is stuck in thick fog, making it difficult to think, talk, listen or even see.

Brain fog is often a symptom of a larger chronic illness. According to a 2015 study[3], brain fog is closely linked to chronic illnesses such as chronic fatigue syndrome, autoimmune disease or postural tachycardia syndrome.

So what causes it? 

As the incidence of chronic illness in western populations increases[4], so is the attention the medical community is giving to brain fog. However, the despite the increased medical examination the exact cause(s) of the condition is unknown.

Brain fog may be due to inflammatory molecules such as histamine from mast cells according to a 2015 study[5]. However an increasingly prevalent hypothesis is that it occurs due to the breakdown of the Blood-Brain-Barrier (BBB) and systematic brain inflammation.

According to Dr William Cole[6], a break-down in intestinal permeability (leaky gut) precipitates the breakdown of the BBB which can eventually lead to brain fog.

We know those with chronic illness often have compromised gut health (as Hippocrates said, all disease begins in the gut!).

Dr Cole explains that Inflammatory proteins in these individuals (such as zonulin), often permeate the gut, enter the blood stream and start attacking the BBB. Once they breakdown the BBB, they cause brain inflammation which can cause anything from ADD to depression, to brain fog.


I was scared to even be asked a question… 

Personally, I have battled brain fog and I I have conquered it. I know from experience just how debilitating the condition can be.

When my chronic illness was at its worst (you can read more about that here) I vividly remember sitting in a meeting at work. My head was so “foggy” I could barely remember my colleagues’ name in the room, let alone keep my train of thought or speak. I remember how scared I was during that meeting that I would be asked a question and I would simply be unable to articulate a response. I felt deflated, depressed and hopeless. Above all I was afraid of what future I could have if that was my brain at 24.

Thankfully, I wasn’t asked a question during that meeting and even more rewarding, I claimed back by mental cognition and so can you! In part two of this post I’ll detail how. Stay tuned!

Rory Linehan is the blogger behind the Paleo PI. Rory developed acute Mononucleosis in his late teens and slowly watched his health unravel over the following years. He developed rosacea, ocular rosacea, lethargy, brain fog, bloating and depression. He spent years troubleshooting his health to no avail until finding the Paleo Autoimmune Protocol (AIP). The AIP gave Rory his life back, restoring his mood and energy as well as giving him a new lease on life for which he is eternally grateful. Rory troubleshoots the final pieces of his health jigsaw at the Paleo PI. The site helps others reclaim their health by providing people the tools to troubleshoot their health through his unique three pronged approach: Nutrition, Lifestyle and Mindset. You can connect with Rory at The Paleo PI website through his Facebook page or on Twitter.








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