Not to go too off-topic here, but I've been reading some articles recently about insulin resistance and Alzheimer's. Unfortunately I can only view the abstracts, but there are some good articles here, here,
. Basically what they're saying is that insulin resistance, along with other factors that accompany diabetes like unwanted metabolites, can lead to a buildup of the type of plaque associated with Alzheimer's, and other neurological diseases. It can also mess with the equilibrium of certain needed chemicals that, when found in abundance in the blood, can have a detrimental effect on memory and cognitive function.
It's nothing fancy like a light helmet, but I figure a change in diet is a whole lot easier--and cheaper--to implement. All you really have to do is understand diabetes and what exactly a diabetic diet entails. If your relative is not insulin resistant (it doesn't even have to be diabetes), than that kind of throws this theory out the window. Unfortunately Alzheimer's is an incredibly complicated disease, and there are probably many underlying factors that can trigger it. I wish I knew more about it, but dietetics being my field of study I've only really looked at the insulin-resistance side of it.
If you like, I can give you some information about a diabetic diet and how insulin resistance works. I had many hours with diabetic patients during my internships. I'm working towards becoming a registered dietitian right now. I'm still a student, but I did do a good bit of work in the field when I got my 2-year degree.
It is said that your life flashes before your eyes just before you die. That is true, it's called Life. [The Last Continent]