I’d been drinking Aspartame-sweetened sodas for fifteen years, and I hadn’t realized I had a problem with them, but last year I stopped drinking sodas for a while because I thought I might be pregnant, and I noticed that my brain fog lessened quite noticeably. Experimentally, I tried drinking sugared sodas rather than diet soda, and my brain fog continued to lessen.
The final evidence, to my mind, came one day when I ordered a Coke Classic at a fast-food restaurant and I was served a Diet Coke by mistake. I was thirsty, and fountain sodas usually taste odd to me at the best of times, so I downed most of it without thinking. By the end of the meal, I was having trouble making sense of my surroundings; I asked my husband for help and he had the sense to take a sip of the drink — that’s how we know it was diet soda.
It’s now been almost a year since I switched back. I still have some brain fog, but not nearly as much as I used to, and my short-term memory seems to be coming back; I can remember phone numbers again now.