Here are some reason why I think you guys might be getting brain fog. So many things can cause it.
One is toxicity issues. Poor liver function can do it. Normal blood testing wont tell the whole picture, you need a Functional Liver Detoxification Profile as it will be a metabolic issue, not that youve got Liver Disease or Cirosis. Its usually treatable with amino acids and balancing out vitamins and minerals and of course all of this leads to detoxification.
Another reason is straight out low testosterone which im sure some of you are onto already.
Another one relates to the liver problems somtimes and that is insulin resistance. Not diabetes. Changing your diet to cut out sugar and include more protein can really help with this one.
Just some ideas…There are so many people getting around with these problems because there are only a few doctors (the number is growing rapidly though) that know how to treat them. Its an option anyway if your out of ideas.