If you are already a coffee drinker, it should be reassuring that after decades of research, no strong link can be found between coffee intake and cancer and, to the contrary, a number of health benefits seem to accompany coffee consumption. But, I’m not sure the evidence is powerful enough to recommend an increase in your daily habit. One reason is that we don’t know for sure that coffee consumption actually caused the health benefits observed in these studies. Some other, unmeasured factor could be responsible. Another reason is that the overall effect was small. And, it’s worth noting that some people are quite sensitive to the side effects of coffee.
Other studies have tried to pinpoint exactly what in caffeine is helping to halt the onset of these diseases. A 2014 study (14) found that caffeine blocks various tau receptors (a protein that contributes to brain cell degeneration). Another study found that caffeinated coffee increased GCSF (15) - a substance greatly decreased in Alzheimer’s patients - levels in the bloodstream.