Thank you for your question! We have an article on the Alzheimers.net blog regarding the possible link between coconut oil and dementia that may be of interest to you. The link is: http://www.alzheimers.net/2013-05-29/...
The link above is useful and there's a link there to the woman whose husband had Alzheimer's and using coconut oil she brought him part-way back.
But I've read other research (sorry, I didn't keep a link) that suggests Tau is the bringer-of-Alzheimer's rather than Amaloid Beta.
And if I remember correctly, other research linked the ingestion of MCTs (Medium Chained Triglycerides) as a way to unclog the Tau protein in a nerve cell so the cell could rid itself of the waste that was being backed up by the non-working Tau. Medium Chained Triglycerides are a component of coconut oil and the oil remains liquid even in the fridge. I personally find as many ways as possible to ingest this oil and another important one... walnut oil, daily. The Walnut Oil is said to tamp down the production of IGF-1 (Insuline-like Growth Factor 1) which by doing so, could lengthen life span.
But another preventative I read about today is the simple act of fasting for at least 12 hours between your evening meal and your next day's meal. Additional 3 hour increments add exponentially to the effect.
I have personally tried to do 3 to four day fasts (a cup of tea daily + water) each major holiday. This regimen is purported to be the best practice to prevent cancer, heart disease, Alzheimer's, disease (through the rebuilding of the immune system through activation of haemotpoietic (blood) stem cells.