What's the solution? I've felt brain fog for 15 years.
When you notice something like that, stop eating it. You may be able to add it back in small quantities later, but for now, just stop.
When you've identified the major ones and stopped eating them, then take stock of where you are. Is it enough? Or do you want to go further?
We started being very careful what we eat because one of my daughters had extreme food sensitivities. I said "Nah, not me, I'm good". But I felt a lot better/less mentally foggy as well.
Fasting is useful for seeing how your mental state is while limiting external food resources (you're using internal fat reserves otherwise), otherwise intermittent fasting is the best option.
This measuring alone ensures that they get enough fats, which seem to be the main reason for brain fog in most people (combined with too much artifical sweets).
Also because of this extreme diet they completely throw all all processed food & artifical sugar/sweets.
I use my own experience with Igg food sensitivity testing and removing those foods to see how I felt after. After allowing my system to calm from the foods then reintroducing just one of the foods that I was conditioned to the discomfort of, it let me see how much discomfort/pain different foods that showed up on the Igg test that make me feel horrible.
Buddhist monks are not supposed to eat after noon, although some cheat by adding a lot of sugar to their evening tea or coffee. This is supposed to keep their minds sharp and clear and aid in meditation. It appears to be a well-tested rule.
Here's one (theoretically) similar example:
https://www.datagraver.com/case/relation-terrorism-attacks-a...
Aubrey de Grey?
1. Sleep study.
2. Vitamin D blood test.
3. Generally a conversation with your doctor who might suggest other tests.
However, the brain fog went away. Brain fog is a common reason people try gluten free or low carb (keto, Meng, etc).
Good luck.
I remember the study with the "rats in a sterile environment" vs "rats in a rich environment" where the latter group formed many more brain connections.
In the end, they found it wasn't the rich environment that caused the brain growth, it was the exercise wheel in it.
All the diets folks recommend are not really proven to help with things like autoimmune disorders (even though some folks swear by them). If it were that simple, it would be standard treatment and no one would go through the side effects that some of the medicines for autoimmune disorders have. I don't know how effective the diets and supplements are for other things, but I'd not trust it unless it came from the mouth of a medical doctor I trusted.
OR because insurances and governments aren't interested in not spending thousands of dollars per month per patient on autoimmune medicines when a simple diet change could do the same thing?
There are more players than doctors. Folks go to specialists all the freaking time for their disorders, but not all disorders need that. You'll probably be just fine going to the normal doctor for type II diabetes. You'll probably go to a neurologist for your MS. Not all disorders need something like the Mayo Clinic. When we suck, we simply suck and that includes the Mayo Clinic and similar clinics.
None of this changes the fact that there isn't evidence that diet helps in the long run for a lot of disorders. Staying generally healthy helps, sure, but saying anything else dupes folks into trying a bunch of weird, non-approved things and buying into snake oils.
Its that easy huh. I'm afraid you got it exactly backwards. Snake oil is the last resort of people who are not being helped by the medical system. People don't love going from one doc to another, being told that "its probably psychological". Countless tests are not great even if they don't bankrupt you. I'm not saying its easy! Most doctors aren't even remotely trained for this, and they don't have the time per patient. Its a difficult task.
What we need are special doctors for chronic diseases. There is a department at a German university (Heidelberg I think), which is being subsidised by the other things they do. They have good successes, helping people that could not be helped for years, but the waiting list is very very very long.
There are special doctors for some chronic diseases - like MS. Most folks go to a normal neurologist, and a few are lucky enough to have some specialists near them. I have nurses that are specialized that I see more than the neurologist as it helps the neurologist see more folks.
That said, not all chronic diseases and conditions need a specialist. Type 2 diabetes is a chronic condition. High blood pressure is a chronic condition (and not always caused by diet/exercise). Depression is chronic. The thing is that some of these are common enough that it is pretty easy for a doctor to know about them. If you are lucky, you see an internist, who specialises in adult general medicine.
Not all chronic diseases and conditions are things that are puzzling either. There is no reason for most folks to see these sorts of specialists, but I wish they were more available for folks that need them. This is a pretty slim portion of patients, though. Some diseases we don't know much about, and we need science to help. I've donated spinal fluid to help things along and I'll donate my body to science after whatever organ donation they'll let me do. I urge others to do similar stuff, and this is why I both want medical records digital and want them to be searchable by researchers. For everyone that doesn't specifically opt out, anyway.
Most of the tests you mention? Yeah, if you are going to see a specialist, they are going to do the tests. Medicine is a profession of puzzles. You take vague symptoms that could have many causes and do tests to rule things out.
Standard doses are way too small to be effective, and most of the science and anecdotes refer to small (1-3g) doses.
Buy hydrolyzed collagen supplements (take 30g per day at start for 1 week) and increase fat intake, simplest is beef tallow (ideally grassfed), eat 2x 5 table spoons of it per day for 5 days at start.
And cut all processed sugar and sweets.
Replace table sugar and fructose with glucose.