Low Dose Methylene Blue. 
Low dose methylene blue also acts on the tau protein. But it has also been 
shown to increase mental activity and reduce mental tiredness. Studies have 
shown it to be effective for memory improvrment even at low doses. Here is a 
link to one study:
es_brain_oxidative_metabolism_and_memory_retention_in_ratshttp://www.biomedexperts.com/Abstract.bme/14724055/Methylene_blue_improv
"Together the findings suggest that low-dose MB enhances spatial memory 
retention in normal rats by increasing brain cytochrome c oxidase activity."

And:
Extinction Memory Improvement by the Metabolic Enhancer Methylene Blue
http://learnmem.cshlp.org/content/11/5/633.full:

Right now I dilute methylene blue to 0.1% and take two drops in the morning and 
two drops in the evening. That dosage is derived from a study done by 
researchers at Children's Hospital & Research Center Oakland.
http://www.sciencedaily.com/releases/2008/08/080818101335.htm
And from other sources. A company is trying to patent methylene blue as an 
Alzheimer's drug and their testing uses much larger doses, 65 mg three times 
daily:

Rember for Alzheimer's: Methylene Blue's Comeback
http://pipeline.corante.com/archives/2008/07/31/rember_for_alzheimers_methylene_blues_comeback.php 

I don't know of anyone trying to treat Alzheimer's with the lower dosage but it 
may work and should at least act as a preventative. If you read the comments to 
the Rember link I provided, commenter 44 says:

"44. jtwiz7 on August 31, 2008 7:40 AM writes...After Dorothy and Denise's 
comments, I discussed it with wife and after ten days,there's a new person in 
our house."

I am corresponding with him currently. His wife has Alzheimer's and the MB is 
helping her greatly. She was using 150 mg twice a day and has changed to 65 mg 
thrice daily.

For those interested in Kentucky lore here is an interesting Kentucky story 
involving methylene blue:
THE BLUE PEOPLE OF TROUBLESOME CREEK
http://www.rootsweb.ancestry.com/~kyperry3/Blue_Fugates_Troublesome_Creek.htm/

Virgin Coconut Oil. 
Virgin coconut oil has many benefits in addition to helping with Alzheimer’s. I 
don’t have a study to reference here but here is a link to a testimonial:Doctor 
says an oil lessened Alzheimer's effects on her husband

http://www.tampabay.com/news/aging/article879333.ece

A quality coconut oil tastes delicious in my opinion and is worth including in 
my opinion. A coconuttery/buttery spread can be made by mixing half butter with 
half coconut oil or the oil can be used in cooking.