the brain thrives on three nutrients - fat, glucose (sugar), and minerals. it needs all three to work at optimum levels. best sources of minerals are kelp, fresh greens (sometimes), and black strap molasses.
this is a mineral supplement i take everyday and absolutely love it.
if nothing else take a big spoonful of frontier brand kelp with some fresh squeezed lemon juice at least once or twice a day. i guarantee you will think better.
oh, and i do agree wit the above suggestions, all of them are great.
Liver Flushing and other cleansings can strip the body of minerals, they MUST be replaced.