The brain is complex organ, and Alzheimer's is a complex disease: a wide range of strategies produce results that look promising while not addressing the root cause. Indeed, distinguishing symptoms from root causes in Alzheimer's is still an ongoing concern. Here is a potential strategy I have not seen mentioned before: "scientists working with laboratory mice have discovered that complete or partial removal of an enzyme that regulates fatty acid levels lessened the memory and learning deficits of Alzheimer's ... The most striking change we discovered in the Alzheimer mice was an increase in arachidonic acid and related metabolites in the hippocampus, a memory center that is affected early and severely by Alzheimer's disease ... an enzyme called group IVA phospholipase A2 (or PLA2) released arachidonic acid [in] the brain ... removal or even partial reduction of PLA2 prevented memory and learning deficits and other behavioural abnormalities in the Alzheimer mice." It is worth noting that PLA2 is upstream in biochemical signaling processes that lead to inflammation - I suspect this has more to do with inflammation than fatty acids per se.

Link: http://www.medicalnewstoday.com/articles/126012.php