A sugar-filled Starbucks latte habit can run up a tab on both your bank account and long-term health. But there is plenty of evidence to support that coffee on its own to start each day — no creamers or sweeteners — can do wonders for you. And according to a brand new study, dark roast coffee, in particular, can be especially beneficial for your brain health.

“Phenylindanes in Brewed Coffee Inhibit Amyloid-Beta and Tau Aggregation” was conducted by researchers at Krembil Brain Institute in Toronto. Their study concluded that dark roast coffee contains phenylindanes, compounds which may reduce your risk of Alzheimer’s and Parkinson’s. Phenylindanes are capable of inhibiting beta-amyloid and tau, two protein fragments that come together and disrupt your neural pathways and are common in Alzheimer’s and Parkinson’s. This was apparently the first time researchers ever studied how phenylindanes interact with the proteins responsible for both diseases.

"Coffee consumption does seem to have some correlation to a decreased risk of developing Alzheimer's disease and Parkinson's disease," says Dr. Donald Weaver, Co-director of the Krembil Brain Institute. "But we wanted to investigate why that is -- which compounds are involved and how they may impact age-related cognitive decline.”

"The caffeinated and de-caffeinated dark roast both had identical potencies in our initial experimental tests," says Dr. Ross Mancini, another researcher from the project. "So we observed early on that its protective effect could not be due to caffeine.”

So why and how is the production of these phenylindanes specific to dark roast coffees?

“Dark roast coffee extracts are more potent inhibitors of Aβ oligomerization (IC50 ca. 10 μg/mL) than light roast coffee extract (IC50 = 40.3 μg/mL), and pure caffeine (1) has no effect on Aβ, tau or α-synuclein aggregation,” the report says. It’s simply that dark roast coffee has the greatest potential for producing phenylindanes in the roasting process than anything else. And the quality of the bean itself matters as well. Coffee beans are actually highly susceptible to molding, and mold toxins in coffee are a major trigger of toxic protein formation in the brain associated with Alzheimer’s. This means cheap, low quality coffee is not likely to do you much good as far as brain health is concerned. A recent study found that just under 92% of green coffee beans were contaminated with mold, and green coffee is unprocessed, which is the most opportune time for mold to grow. Many large processing facilities don’t actually clean their tanks between batches of coffee beans. The mold then grows in the bottoms of these tanks and contaminates the next batch of beans.

"What this study does is take the epidemiological evidence and try to refine it and to demonstrate that there are indeed components within coffee that are beneficial to warding off cognitive decline,” Mancini says about the study. “It's interesting but are we suggesting that coffee is a cure? Absolutely not.”