This vice is coffee, not decaf, but the regular caffeinated variety. So how does it work? In a study on mice, which are biologically similar to humans, researchers found that mice genetically "destined" to produce the mis-folded tau proteins seen in Alzheimer's disease did not produce enough of an enzyme known as NMNAT2. Because of this, they tested over 1,280 compounds to see if they had any effects on NMNAT2 production in brain cells. Caffeine was one of the most active substances in increasing NMNAT2, and when they tested it on the mice, they began to produce normal levels of the enzyme. Of course, this is just an animal study; we need human research to confirm these effects.
|Source: Julius Schorzman|
Caffeine is more than an intoxicant, in fact, there is a lot of science behind its effects against dementia - this is far from "wishful thinking" by busy doctors who want an excuse for their coffee habit. There is a strong inflammatory component of the development of Alzheimer's disease, and part of this is over-reactivity of the glial cells, which act as part of the brain's immune system. Caffeine's effects on the adenosine receptors in the central nervous system have been found to reduce this over-reaction, and so inhibit inflammation. The blood-brain barrier (BBB) has also been shown to play a role in Alzheimer's disease; if it is too "leaky", it can speed the buildup of harmful proteins. And yes, caffeine may protect BBB integrity, partly by calming the glial cells. Animal studies have shown that all of this reduction in inflammation may translate to the prevention of memory problems. Despite a lack of human clinical trials, all of this helps to validate the benefits of caffeine seen in population studies. In conclusion, it may not be best to completely give up coffee in order to improve your health, as moderate caffeine consumption could prevent you from nasty neurodegenerative diseases later.