A couple of days ago I found out this intriguing study: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0012244 and http://www.telegraph.co.uk/health/healthnews/7989889/Vitamin-B-is-revolutionary-new-weapon-against-Alzheimers-Disease.html
The study shows that the rate of brain shrinkage can be greatly reduced by the use of large amounts of vitamins B6, B12 and Folic acid, resulting in an improved evolution for Alzheimers patients. I wonder if this study is pointing toward a new type of support for the paleo diet, since most standard western diets are quite limited in terms of vitamin B. Also it seems to imply that Alzheimers is a condition derived from a nutritionally deficient diet. What do you say?