My Dr. put me on a Paleo diet just to eliminate junk. It does help a little & really helps IBS issues - just not so much with the brain fog.
I wish that I could say that I have had something that I can control that helps, but I don't. I have found right before and during flares my brain fog is much worse. I try to make sure that I'm getting enough sleep, eating, hydrating and all that stuff.
you know my son made a comment to me about that and alot of stomach issues from meds lately and he said mom you really need to drink more water and Im not very good at that but I did push alot of ICE TEA yesterday and I slept so good last night and was the first time in 2 months I didnt wakeup from stomach pain and upset and I actually feel better this morning and less brain fog, and I really contribute it to getting more fluids in me and wonder if I wasnt dehydrated,, I have put pushing fluids on my daily list because my brain feels much clear today!
I have found that my vitamin D was very low causing sever memory loss. Have DR check blood results for your D level maybe prescription D would help you!
I've been low carb as well......lost 47 lbs. I still have brain fog as well!
I have suffered from brain fog for years due to my thyroid disease. I even had to explain it to thr SSI lady when I was starting to get my SSI. With RA your meds plus the chronic fatigue add to the brain fog. It is a real problem and I live with it. I tell them to forgive me if I forget something. They know me and smile or laugh with me.