By Kimiya Oveisi
Whether enjoyed in a latte, Americano, or even a martini, espresso coffee provides an ultra-concentrated jolt of caffeine. But it might do even more for one’s alertness over the long run, according to new research.
In vitro laboratory tests shows espresso compounds can inhibit tau protein aggregation, which is one of the processes believed to be involved in the onset of Alzheimer’s disease.
Although the exact mechanisms that cause dementia are still unclear, a protein called tau plays a significant role. In healthy people, tau proteins help stabilize structures in the brain, but when certain diseases develop, the proteins can clump together into fibrils.
Scientists believe the ‘tangles’ are one of the key causes of dementia – slowing thinking and memory skills.
Some researchers propose that preventing this aggregation could alleviate symptoms. So, Mariapina D’Onofrio and colleagues at Verona University in Italy—where they drink a lot of espresso—wanted to see if compounds in the coffee could prevent tau clumping in lab experiments.
The researchers pulled espresso shots from store-bought beans, then characterized their chemical makeup using nuclear magnetic resonance spectroscopy. They chose caffeine and trigonelline, both alkaloids, along with the flavonoid ‘genistein’ and ‘theobromine’—a compound also found in chocolate—to focus on in further experiments.
These molecules individually, along with the full espresso extract, were incubated alongside a shortened form of the tau protein for up to 40 hours. As the concentration of espresso extract, caffeine or genistein increased, fibrils were shorter and didn’t form larger sheets, with the complete extract showing the most dramatic results.
Shortened fibrils were found to be non-toxic to cells, and they did not act as “seeds” for further clumping.
In other experiments, the researchers observed that both caffeine and the espresso extract could bind pre-formed tau fibrils.
Italians knock back some 30 million espressos each day in little cups, and multiple studies in the last decade showed that the drink could have beneficial effects thanks to its antioxidants and plant chemicals which dampen inflammation.
Regular consumption has been linked to reduced risk of premature death—protecting against heart disease, type 2 diabetes, liver disease, Parkinson’s and some cancers.
Prof D’Onofrio said: “Coffee extracts contain a large variety of bioactive compounds exhibiting health-beneficial effects. We were able to identify the most abundant constituents.
“We have presented a large body of evidence that espresso coffee is a source of natural compounds showing beneficial properties in ameliorating tau-related pathologies.”
Although much more research is needed, the team, which published their results in the American Chemical Society’s Journal of Agricultural and Food Chemistry, says that their preliminary in vitro findings could pave the way toward designing bioactive compounds that could protect against neurodegenerative diseases, including Alzheimer’s. An Espresso a Day Could Keep Alzheimer’s at Bay by Preventing Tau Clumping
