Link between inflammation and brain fog

Link between inflammation and mental sluggishness shown

An estimated 12M UK citizens have a chronic medical condition, and many of them report severe mental fatigue that they characterize as ‘sluggishness’ or ‘brain fog’. This condition is often as debilitating as the disease itself.

In a study published in Neuroimage , they show that inflammation appears to have a particular negative impact on the brain’s readiness to reach and maintain an alert state.

Dr Ali Mazaheri and Professor Jane Raymond of the University’s Centre for Human Brain Health, are the senior authors of the study. Dr Mazaheri says: “Scientists have long suspected a link between inflammation and cognition, but it is very difficult to be clear about the cause and effect. For example, people living with a medical condition or being very overweight might complain of cognitive impairment, but it’s hard to tell if that’s due to the inflammation associated with these conditions or if there are other reasons.”


Illness is often accompanied by perceived cognitive sluggishness, a symptom that may stem from immune system activation. The current study used electroencephalography (EEG) to assess how inflammation affected three different distinct attentional processes: alerting, orienting and executive control. In a double-blinded placebo-controlled within-subjects design (20 healthy males, mean age = 24.5, SD = 3.4), Salmonella typhoid vaccination (0.025 mg; Typhim Vi, Sanofi Pasteur) was used to induce transient mild inflammation, while a saline injection served as a placebo-control. Participants completed the Attention Network Test with concurrent EEG recorded 6 h post-injection. Analyses focused on behavioral task performance and on modulation of oscillatory EEG activity in the alpha band (9–12 Hz) for alerting as well as orienting attention and frontal theta band (4–8 Hz) for executive control. Vaccination induced mild systemic inflammation, as assessed by interleukin-6 (IL-6) levels. While no behavioral task performance differences between the inflammation and placebo condition were evident, inflammation caused significant alterations to task-related brain activity. Specifically, inflammation produced greater cue-induced suppression of alpha power in the alerting aspect of attention and individual variation in the inflammatory response was significantly correlated with the degree of alpha power suppression. Notably, inflammation did not affect orienting (i.e., alpha lateralization) or executive control (i.e., frontal theta activity). These results reveal a unique neurophysiological sensitivity to acute mild inflammation of the neural network that underpins attentional alerting functions. Observed in the absence of performance decrements, these novel findings suggest that acute inflammation requires individuals to exert greater cognitive effort when preparing for a task in order to maintain adequate behavioral performance.


Here are some tips on reducing inflammation from sites that appear credible.

Foods that cause inflammation

Try to avoid or limit these foods as much as possible:

  • refined carbohydrates , such as white bread and pastries
  • French fries and other fried foods
  • soda and other sugar-sweetened beverages
  • red meat (burgers, steaks) and processed meat (hot dogs, sausage)
  • margarine , shortening, and lard

Anti-inflammatory foods

An anti-inflammatory diet should include these foods:

  • tomatoes
  • olive oil
  • green leafy vegetables , such as spinach, kale, and collards
  • nuts like almonds and walnuts
  • fatty fish like salmon, mackerel, tuna, and sardines
  • fruits such as strawberries, blueberries, cherries, and oranges

More tips:


This is very valuable information. Thank you.
Bookmarked it.

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There seem to be a lot of links between inflammation, gut bacteria, and food.

Here are two related articles from my browser tabs:

Sugar binges increase risk of inflammatory bowel disease

“We wanted to know how long it takes before a change in diet translates into an impact on health. In the case of sugar and colitis, it only took two days, which was really surprising to us. We didn’t think it would happen so quickly.”

What could drive such a significant change in such a short time? It turns out it’s all about gut bacteria and the impact food has on them.

Fibre-rich foods act as fuel for the “good” bacteria that live in the gut and produce short-chain fatty acids, which are critical for an efficient immune response. Eating high-sugar diets and decreasing intake of fibre feeds “bad” microbes, such as E. coli, that are associated with inflammation and a defective immune response.

Bacteria in the gut may alter aging process

The team showed that the increased neurogenesis was due to an enrichment of gut microbes that produce a specific short chain fatty acid, called butyrate.

Butyrate is produced through microbial fermentation of dietary fibres in the lower intestinal tract and stimulates production of a pro-longevity hormone called FGF21, which plays an important role in regulating the body’s energy and metabolism. As we age, butyrate production is reduced.


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I would like to know people experience with spicy and fried food.

For me I completely stopped eating fried food as I observed its connection to my brain fog and I never feel energetic after any fried meal.

I am still not sure about spicy food if it causes for me digesion problems or inflammation.

I quit eating fried food too. That page from Harvard Medical School lists fried foods as one of the things that can cause inflammation.

I’m not sure about spicy foods, but I found this article:

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I think moderation is the key regarding spicy food or anything actualy.

But Do you remember having brain fog after fried meal?

I’ve only had fried food once in many years and don’t remember. I went for a walk afterwards and don’t think I was trying to do anything cognitively difficult, so I might not have noticed.

I tried everything till I got to exercising well enough, and followed by a healthy recovery. Much more efficient than all the curcuma (huge dosages!)and all foods ive tried while struggling so hard in the hopes it would help.

Exercise, recovery! Exercise, recover … Sergeant!

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could you share your daily exercising routine ?

When I can go out it’s approximately 400 steps going uphill as fast as I can or minimum 2 hour walk as fast as I can with Afghan walk breathing in the following way :
3-1-3-1: breath in for three steps, hold breath for one step, breath out for three steps, hold breath for one step, start over.

if I can’t go out, I do a mixture of Tai Chi and stretching and aerobics in a Tabata (1-2minutes highest intensity) style routine. No specific hours, just a few times a day, everyday.

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That’s interesting.

Related to that, I was reading a few days ago that inflammation of the brain causes depression. It seems by this study that taking anti inflammatory, such as ibuprofen can reduce depression.

Brain fog is also a symptom of low cortisol ( often found in ME) I have massive brain fog as I don’t produce cortisol (Addison’s Disease). My saving grace is a good imagination but I do have a reduced ability to follow things.

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