[1] https://newsnetwork.mayoclinic.org/discussion/mayo-clinic-mi...
Or is this a viral condition as others in the thread have mentioned? Perhaps these are not mutually exclusive?
Rhinovirus, the cause of the common cold, binds to vLDL receptors. vLDL incidentally being the primary risk factor for cardiovascular disease https://www.ncbi.nlm.nih.gov/pubmed/12857919
Influenza requires the cholesterol transport system to bud and spread http://news.mit.edu/2017/cholesterol-helps-flu-virus-escape-...
Hepatitis C virus relies on APO-E, our favorite alzheimers gene, to flourish, and APO-E genotype predicts if you will get liver cancer from Hep-B https://goo.gl/images/Hev5ev
T2D, CVD, and obesity, being characterized by hypercholesterolemia and mitochondrial dysfunction, are illnesses that are supportive of viral infections. They also promote AGE formation, which activates the innate immune system through a variety of RAGE receptors, Galectin-3 being potentially a central axis as it is also part of the senescent phenotype.
There are a number of pathways that seem to be downregulated by purigenic receptors, many of which are sensitive to adenosine. Caffeine blocks adenosine receptors and blocks signaling.
What could be happening here is suppressing inflammation, since evidently purine nucleotides activate some immune cells.
I'm not trying to hand wave over anything, but it's hard to justify comparing cause of death stats from nearly 100 years ago to current era when we've made so many strides in combating some previously fatal diseases that are now routinely treatable or even preventable.
Alzheimer's sucks. Dementia sucks. I've worked for/with people with Alzheimer's and it's never pretty. I lost my own Grandfather to dementia last year. Neither is pretty, and the both do the same damage: typically the person suffering from the disease isn't even aware, but all family and close associates suffer instead. It's brutal to all involved.