Alzheimer's and Caffeine: It's Not Just Mice

I'm taking a break from the usual futile political analysis for something that may actually help someone somewhere.  You may have heard about this news when it was published in 2009:

[The] Florida ADRC study included 55 mice genetically altered to develop memory problems mimicking Alzheimer's disease as they aged. After behavioral tests confirmed the mice were exhibiting signs of memory impairment at age 18 to 19 months – about age 70 in human years – the researchers gave half the mice caffeine in their drinking water. The other half got plain water. The Alzheimer's mice received the equivalent of five 8-oz. cups of regular coffee a day. That's the same amount of caffeine – 500 milligrams -- as contained in two cups of specialty coffees like Starbucks, or 14 cups of tea, or 20 soft drinks.
At the end of the two-month study, the caffeinated mice performed much better on tests measuring their memory and thinking skills. In fact, their memories were identical to normal aged mice without dementia. The Alzheimer's mice drinking plain water continued to do poorly on the tests.

(The PDF version of the study is here.)
My father has had progressing symptoms of dementia (not formally diagnosed as Alzheimer's, though that's been both our assumption and his doctors') for several years, and it had gotten to the point where he was so cognitively impaired that he couldn't recall the names of just about anyone other than immediate family and he was sleeping 20+ hours a day.  On my most recent trip home my mother mentioned that he'd stopped drinking coffee, but while I was there we happened to give him a few cups—and we noticed an immediate and dramatic improvement in his awareness, alertness, short-term and long-term memory, level of engagement, and many other more subtle things as well.  It was like having my old dad back.
In researching a possible connection I came across the 2009 study mentioned above, and since then we've been making sure he has at least 5 cups of coffee a day (which translates roughly into the 500mg dose mentioned in the study).  It's continued to have a dramatic effect, which we see within a few minutes—"like watching a flower open in time-lapse", as my mother said—and lasts throughout the day as we supplement the coffee dosage.  I wouldn't have believed it until I saw it happen for myself; after years of watching my father drift further and further away from us, it's nothing short of miraculous.  Luckily for us he loves coffee (that's one of the things he seemed to have forgotten), but if that ever becomes a problem we'll try adding caffeine pills to his daily pharmaceutical regimen.
So if you know someone with symptoms of dementia, try giving them caffeine, and if you know someone who knows someone with symptoms of dementia, tell them to try giving that person caffeine.  There are no guarantees that it will have the same effect it did with my dad, of course, but it's so simple and low-risk there's no reason not to try it.  Seriously: tell everyone and anyone you know who might benefit from this, because it could literally change their lives.
If you do try this I'd be very interested to hear what kind of results you see, whether positive, neutral or negative.
(A little more on my father here, if you're interested.)
MORE INFO: Here's an excerpt from the abstract for a 2002 study:

Patients with AD [Alzheimer's disease] had an average daily caffeine intake of 73.9 ± 97.9 mg during the 20 years that preceded diagnosis of AD, whereas the controls had an average daily caffeine intake of 198.7 ± 135.7 mg during the corresponding 20 years of their lifetimes (P < 0.001, Wilcoxon signed ranks test). Using a logistic regression model, caffeine exposure during this period was found to be significantly inversely associated with AD (odds ratio=0.40, 95% confidence interval=0.25–0.67), whereas hypertension, diabetes, stroke, head trauma, smoking habits, alcohol consumption, non-steroid anti-inflammatory drugs, vitamin E, gastric disorders, heart disease, education and family history of dementia were not statistically significantly associated with AD. Caffeine intake was associated with a significantly lower risk for AD, independently of other possible confounding variables.

So consuming 198.7 ± 135.7 mg of caffeine a day may help you avoid Alzheimer's.