New study discovers why coffee can protect the brain, and it has to do with the kind of roast you drink

Although scientists already believed that drinking coffee could possibly reduce the risk of neurodegenerative conditions such as Alzheimer's disease, a new study by Krembil Brain Institute in Toronto, Canada suggests that the kind of roast you drink might determine how much protection your cup of joe might actually give you.
The study has identified the set of compounds in coffee – phenylindanes, produced during the roasting process – that are responsible for protecting the brain. The darker the roast, the more phenylindanes are produced. This suggests that dark roasted coffee, with or without caffeine, is the most beneficial for your brain.
According to Medical News Today:

It is the phenylindanes, rather than any other coffee-related compounds, that seem to inhibit the amalgamation of tau and beta-amyloid. These are toxic proteins, of which the excessive buildup in the brain is a key factor in neurodegenerative conditions such as Alzheimer's and Parkinson's disease.
'So phenylindanes are a dual inhibitor. Very interesting, we were not expecting that,' Dr. [Donald] Weaver [co-director of the Krembil Brain Institute] acknowledges.
It appears that a longer roasting time causes the coffee beans to produce more phenylindanes. This suggests that dark roasted coffee — whether regular or decaf — has the strongest protective effect on the brain.
'It's the first time anybody's investigated how phenylindanes interact with the proteins that are responsible for Alzheimer's and Parkinson's,' says Dr. [Ross] Mancini.
This study doesn't mean dark roasted coffee is a cure for Alzheimer's or Parkinson's, but it gives me a good excuse to drop the tea and start drinking espresso on a daily basis again.

Image: by Max Pixel – Creative Common Zero – CC0