Discovery may help to track, combat Alzheimer's
January 1, 2021
A better understanding of Alzheimer’s disease
Some very good news to report when it comes to battling Alzheimer’s disease: A novel form of an Alzheimer’s protein found in the fluid that surrounds the brain and spinal cord indicates what stage of the disease a person is in, according to a study by researchers at Washington University School of Medicine in St. Louis. Tau tangles are thought to be toxic to neurons, and their spread through the brain foretells the death of brain tissue and cognitive decline. Tangles appear as the early, asymptomatic stage of Alzheimer’s develops into the symptomatic stage.
The discovery of so-called microtubule binding region tau (MTBR tau) in the cerebrospinal fluid could lead to a way to diagnose people in the earliest stages of Alzheimer’s disease, before they have symptoms or when their symptoms are still mild. It also could accelerate efforts to find treatments for the devastating disease, by providing a relatively simple way to gauge whether an experimental treatment slows or stops the spread of toxic tangles.
The study, which was published Dec. 7 in the journal Brain, may lead to significant advances in combating the disease.
“If we can translate this into the clinic, we’d have a way of knowing whether a person’s symptoms are due to tau pathology in Alzheimer’s disease and where they are in the disease course, without needing to do a brain scan,” said study senior author Dr. Randall J. Bateman, who is a professor of neurology at Washington University School of Medicine in St. Louis, Missouri. “As a physician, this information is invaluable in informing patient care, and in the future to guide treatment decisions,” Dr. Bateman said.
Alzheimer’s begins when a brain protein called amyloid starts forming plaques in the brain. During this amyloid stage, which can last two decades or more, people show no signs of cognitive decline. However, soon after tangles of tau begin to spread in the neurons, people start exhibiting confusion and memory loss, and brain scans show increasing atrophy of brain tissue.
Tau tangles can be detected by positron emission tomography (PET) brain scans, but brain scans are time-consuming, expensive and not available everywhere. Dr. Bateman and his colleagues are developing diagnostic blood tests for Alzheimer’s disease. The researchers analyzed cerebrospinal fluid from 100 people in their 70s. The researchers found that levels of a specific form (MTBR tau 243) in the cerebrospinal fluid were elevated in the people with Alzheimer’s and that it increased the more advanced a person’s cognitive impairment and dementia were.
A cup of hot chocolate may boost brain power
Grab a cup of hot chocolate the next time you have a taxing problem to tackle. Increased consumption of flavanols, which are a group of molecules which occur naturally in fruit and vegetables, may increase your mental agility, according to new research at the University of Birmingham in England. A team in the University’s School of Sport, Exercise and Rehabilitation Sciences has found that adults given a cocoa drink containing high levels of flavanols were able to complete certain cognitive tasks more efficiently than when drinking a non-flavanol enriched-drink.
The study participants underwent non-invasive brain imaging to measure blood oxygenation levels in the brain. Working with experts at the University of Illinois, the researchers showed that participants who had consumed the flavanol-rich drink produced a faster and greater increase in blood oxygenation levels in response to artificially elevated levels of CO2.
Flavanols, a sub-group of plant flavonoids, are present in cocoa, grapes, apples, tea, berries and other foods. They are known to have a beneficial effect on cardiovascular health, but their effects on brain health are not well understood. This study, published in Scientific Reports, involved cocoa, but flavanols are extremely common in a wide range of fruit and vegetables.
“By better understanding the cognitive benefits of eating these food groups, as well as the wider cardiovascular benefits, we can offer improved guidance to people about how to make the most of their dietary choices,” said lead study author Dr. Catarina Rendeiro, who is with the University of Birmingham’s School of Sport, Exercise and Rehabilitation Sciences.
In the cognitive tests, the researchers found significant differences in the speed and accuracy with which volunteers completed the higher complexity tasks. The volunteers who had taken the flavanol-enriched
drink performed the tasks 11% faster on average.
“Our results showed a clear benefit for the participants taking the flavanol-enriched drink, but only when the task became sufficiently complicated,” Dr. Rendeiro said.
John Schieszer is an award-winning national journalist and radio and podcast broadcaster of The Medical Minute. He can be reached at a href='mailto:email@example.com'>firstname.lastname@example.org.