"Nutrition and Alzheimer's disease: The detrimental role of a high carbohydrate diet", S.Seneff, G.Wainwright, L.Mascitelli, European Journal of Internal Medicine 22 (2011) 134–140.
"A ketogenic diet has been found to be therapeutic in AD patients [72,73]. It involves an extremely high fat diet, with up to 88% of calories derived from fats. This benefit may be likely due in part to the bioavailability of a plentiful supply of fats to repair damaged membranes. However, this diet leads to the generation of a significant concentration of ketone bodies in the blood serum, which can be used as an alternative fuel to glucose ..."
A very good and brief summary by Ted Hutchison is here (TUESDAY, 11 OCTOBER 2011).