“Brain theft.” The habit of nasal gnawing may be a cause of serious illness

A study conducted in mice by researchers from Griffith University found a small link between nasal necrosis and the accumulation of proteins associated with the brain stealing disease.

The researchers said that tampering with the nose may lead to damage to the internal protective tissues, making it easier for dangerous bacteria to reach the brain.

The brain, in turn, responds to this intrusion in a way that reflects the conditions resulting from the devastating Alzheimer's disease, which gradually affects the brain functions and memory of those affected, and becomes more serious over time.

During the study, the team at Griffith University in Queensland, Australia, conducted tests on bacteria called Chlamydia pneumoniae, a rare type of germ that can cause respiratory infections such as pneumonia.

They also discovered these bacteria in the brains of people with late dementia.

Research conducted in 1998 found these bacteria in 17 out of 19 brain samples evaluated.

The scientists said at the time: “Some indirect evidence appears to suggest that infection with the organism may be linked to dementia.”

Now, researchers at Griffith University have found that the bacterium Chlamydia pneumoniae “used the nerve running between the nasal cavity and the brain as a pathway to invade the central nervous system.”

The researchers added that when there was damage to the thin tissue lining the nose, called the nasal epithelium, nerve infections were more serious.

Cells in the mice's brains responded to the bacteria by depositing more amyloid beta proteins, a "hallmark of Alzheimer's disease."

The Alzheimer's Association says a key component of this brain-stealing disease is the buildup of plaques, which form when beta-amyloid proteins clump together.

Study co-author and head of the Clem Jones Center for Neurobiology and Stem Cell Research, Professor James St John, said: “We are the first to show that Chlamydia pneumoniae can reach directly into the nose and into the brain, where it can cause Alzheimer’s-like diseases. "We've seen this happen in a mouse model, and the evidence is likely to be frightening for humans as well."

The researchers noted the speed with which the bacteria invaded the central nervous system of the mice, taking between 24 and 72 hours.

“The time frame for infection of the central part by K. pneumoniae was much faster than previously shown,” they wrote in the study published in the journal Scientific Reports.

They pointed out that the olfactory nerve located in the nose provides a short path for bacteria and viruses to the brain.

It is not clear from the study whether this process would also occur in humans. Furthermore, Alzheimer's disease occurs through a series of complex mechanisms.

Professor St John said: “We need to apply this study to humans and confirm whether the same pathway works in the same way. It is research that many have suggested, but it is not yet complete. "What we know is that these same bacteria exist in humans, but we haven't figured out how they got there."

In future studies, the team also seeks to look into whether increased amyloid beta protein deposits are a normal immune response that can be reversed when fighting infection.

Smoking causes brain shrinkage that may cause dementia

A study conducted by researchers at Washington University School of Medicine in St. Louis found that smoking likely leads to brain shrinkage.

The results say that quitting smoking can prevent further loss of brain tissue, but stopping smoking does not return the brain to its original size.

The researchers explained that human brains naturally lose volume with age, but smoking effectively causes the brain to age prematurely.

The findings, published inthe journal Biological Psychiatry: Global Open Science, help explain why smokers are at greater risk of age-related cognitive decline and Alzheimer's disease. .

Lead researcher Laura J. “Until recently, scientists ignored the effects of smoking on the brain, partly because we focused on all the terrible effects smoking has on the lungs and heart,” said Dr. Perot, MD, professor of psychiatry. But when we started looking at the brain more closely, it became clear that smoking is really bad for the mind.”

Scientists have long known that smoking and small brain size are linked, but they have never been sure of the cause. There is a third factor to take into consideration: genetics.

According to scientists, both brain size and smoking behavior are genetic. Nearly half of a person's risk of smoking can be attributed to his or her genes.

To untangle the relationship between genes, brains and behaviour, Beirut and the study's first author Yunhu Zhang, a graduate student, analyzed data from the UK Biobank, a publicly available biomedical database containing genetic, health and behavioral information on half a million people, most of whom are... European origin.

A subset of more than 40,000 UK Biobank participants underwent brain imaging, which can be used to determine brain size.

In total, the team analyzed de-identified data on brain size, smoking history and genetic risks of smoking in 32,094 people.

Each pair of factors has been shown to be related to each other: smoking history and brain size, genetic risk of smoking and smoking history, and genetic risk of smoking and brain size.

Moreover, the association between smoking and brain size is dose-dependent. The more packs a person smokes daily, the smaller the size of his brain.

When the three factors were taken into account together, the association between genetic risk for smoking and brain size disappeared, while the association between each of these factors and smoking behaviors remained.

Using a statistical approach known as mediation analysis, the researchers found that genetic predisposition leads to smoking, which leads to decreased brain size.

Unfortunately, the downturn appears to be irreversible. By analyzing data on people who quit smoking years ago, researchers found that their brains remained permanently smaller than the brains of people who had never smoked.

“You can't undo damage that's already been done, but you can avoid causing more damage,” Zhang said. Smoking is a modifiable risk factor. "One thing you can change to stop your brain aging and putting yourself at increased risk of dementia is to quit smoking."