It’s difficult to conduct research studies that definitely prove cause and effect associations between what we consume and brain function. It’s intuitive that this would be true, though.

My experience supports this. My daughter has a seizure disorder, and until a few years ago she seizured through progressively higher numbers and doses of anti-seizure meds. Then we changed her diet, mainly eliminating processed sugars. Almost immediately the seizures stopped and she is now on a low dose of one med. And, when in the hospital three years ago she had seizures triggered by IV glucose. So, high glycemic sugars clearly affect her brain adversely.