- A recent study from the University of Verona in Italy asks whether espresso could possibly help reduce the risk of dementia.
- The preliminary research, which was conducted in vitro, in the laboratory, found an association between higher concentrations of caffeine and the inhibition of tau protein aggregates, a hallmark of Alzheimer’s disease and other forms of dementia.
- It remains unclear whether drinking coffee could actually keep dementia at bay for longer.
A high concentration of caffeine — which some might associate with drinking an espresso — might help reduce the risk of dementia, according to a study published in the ACS Journal of Agricultural and Food Chemistry.
In preliminary in vitro laboratory tests, researchers found that espresso compounds might inhibit tau protein aggregation, a process believed to be involved in the onset of Alzheimer’s disease, the most common form of dementia.
The scientists first pulled espresso shots from store-bought beans. Then, they characterized the chemical makeup and chose several molecules, including caffeine.
The test included the molecules and the complete extract. They were incubated alongside a shortened form of the tau protein for at least 40 hours.
As the caffeine concentration increased, tau fibrils did not form larger sheets, with the complete extract showing the most dramatic results. Ultimately, the fibrils were nontoxic to cells and did not act as seeds for further aggregation.
“This was an interesting study by a group of scientists in Verona, Italy, who are trying to help change espresso coffee use from a potential health risk to a health benefit,” explained Clifford Segil, a board-certified neurologist at Providence Saint John’s Health Center in Santa Monica, CA, not involved in the study.
“[The researchers] noted that, in test tubes, adding coffee brew to a protein called tau, made the tau protein stop from forming into something that has been shown to present in neurological diseases which cause memory loss and shaking,” Segil told Medical News Today.
“Tau is present in patients with Alzheimer’s dementia and Parkinson’s disease. In the present study, adding coffee brew to a simple form of the tau protein prevented the tau protein from aggregating, condensing, and seeding activity. The goal is to design a therapy for these diseases using a coffee brew extract base.”
– Clifford Segil
However, Segil also noted that it is unclear whether the study findings will actually lead to a new therapeutic strategy against neurodegenerative conditions.
“Unfortunately, many modern neuroscientists believe these tau proteins may be more akin to freckles, which are most often normal aging pigments, rather than an accumulation that causes neurological disease,” he noted.
“No medication affecting tau structure [has] […] shown any clinical benefits to clinical neurologists like me who treat patients with neurodegenerative diseases like [the] Alzheimer’s [form of] dementia or Parkinson’s disease,” Segil cautioned.
Coffee is a source of antioxidants in the form of polyphenols, which has led some researchers to suggest that it can bring various health benefits including lowering the risk of type 2 diabetes and some forms of cancer. It may also have beneficial effects on brain health.
That may be because antioxidants from a person’s diet can help protect against cellular aging. However, antioxidants alone are unlikely to offer full protection against any disease or health condition.
“Antioxidant substances that claim to be neuroprotective are plentiful,” Segil told MNT, “and in theory, they may actually be healthy, but claims [that a] coffee brew is going to protect someone from getting a neurodegenerative disease is challenging to agree has scientific merit.”
Nevertheless, the researchers who conducted the current study say that their preliminary in vitro findings could pave the way toward finding or designing other bioactive compounds against neurodegenerative diseases, including Alzheimer’s.
Dr. Joel Salinas, a neurologist at NYU Langone Health, not involved in the study, pointed out that this is very early research, and several other areas of investigation need to be explored.
“For example,” he told us, “causation has not yet been established — other studies have shown that drinking coffee [was associated with] an increased risk of dementia.”
“It could be a matter of finding dividing lines — how much coffee is preventative and how much is harmful,” Dr. Salinas hypothesized. “These [questions] must be answered before designing, or attempting to design, treatments for neurodegenerative diseases.”
Tau helps stabilize the internal skeleton of nerve cells (neurons) in the brain, according to the Alzheimer’s Association.
When tau proteins cling to other tau proteins, they form tau tangles, a hallmark sign of Alzheimer’s disease.
This accumulation of tau proteins can damage or kill brain cells in several forms of dementia, including Alzheimer’s and frontotemporal dementia. The tangles cause the internal skeleton to fall apart, causing problems with thinking and memory.
According to the National Institutes of Health, in addition to Alzheimer’s disease, tau proteins may contribute to disease in:
- Parkinson’s disease
- frontotemporal dementia
- Pick’s disease
- progressive supranuclear palsy
- corticobasal degeneration.
Scientists continue to look for ways to slow or stop tau cells from damaging healthy cells.
Diagnosing Alzheimer’s requires expensive imaging, which is not always available to patients.
That is why scientists are working on a way to detect Alzheimer’s in its early stages. Researchers at the University of Pittsburgh developed a test to detect a biomarker called “brain-derived tau.”
They say it outperforms current tests. It is specific to Alzheimer’s and looks at the levels of tau in the blood, which correlates to the severity of amyloid plaques and tau tangles in the brain.
The researchers plan large-scale clinical trials with various racial and ethnic backgrounds.