Sanjay Gupta, CNN medical correspondent and author of the new book Keep Sharp: Building a Better Brain at Any Age,

 You'll want to read the whole thing, I have almost all of this but spread out over 22,000 posts.

A good review of the book here:

Advice for keeping your brain at its best

One line from the review: this reader, for one, headed straight to the bathroom and threw out all the Benadryl in the medicine cabinet, brushed and flossed, Googled “turmeric recipes,” ordered a bottle of L-serine, then scaled a couple of San Francisco hills.