In cases where messing with the nose damages internal tissues, important types of bacteria have a clearer pathway to the brain, which responds to their presence in ways similar to signs of Alzheimer’s disease.
There are a lot of caveats here, not the least of which is that the supporting research to date has been based on mice rather than humans, but the findings certainly deserve more research — and could improve our understanding of how Alzheimer’s disease begins, which remains a mystery.
A team of researchers led by scientists from Griffith University in Australia conducted tests on bacteria called chlamydia pneumoniae, which can infect humans and cause pneumonia. The bacteria have also been detected in the majority of the brains of humans with late-onset dementia.
It has been shown that in mice, the bacteria can travel through the olfactory nerve (to join the nasal cavity and brain). Moreover, when there is damage to the nasal epithelium (the thin tissue along the roof of the nasal cavity), nerve infections worsen.
This caused the mice’s brains to deposit more amyloid beta – a protein released in response to infection. Plaques (or clumps) of this protein have also been found in high concentrations in people with Alzheimer’s disease.
We are the first to show that chlamydia pneumoniae “It can reach directly into the nose and into the brain where it can cause Alzheimer’s-like diseases,” says neuroscientist James St. John of Griffith University in Australia.
“We’ve seen this happen in a mouse model, and the evidence is potentially scary for humans as well.”
Scientists were surprised by how quickly it was done pneumococcus It settled in the central nervous system of mice, with infection occurring within 24 to 72 hours. It is believed that bacteria and viruses see the nose as a highway to the brain.
While it is not certain that the effects will be the same in humans, or even that beta-amyloid plaques are a cause of Alzheimer’s disease, it is nonetheless important to pursue the promising results in the fight to understand this common neurodegenerative condition.
“We need to do this study in humans and see if the same pathway works the same way,” says St. John.
“It’s research that has been suggested by many people, but it’s not yet complete. What we do know is that these same bacteria are found in humans, but we haven’t determined how they got there.”
Nose picking is not uncommon. In fact, 9 out of 10 people could do it…not to mention a host of other types (some a bit more skilled than others). While the benefits are not clear, studies like this one should give us pause before making a choice.
Future studies of the same processes are planned in humans — but until then, St. John and colleagues suggest that sucking your nose and plucking your nose hair is “not a good idea” because of the potential damage it does to the protective nasal tissue.
One prominent question that the team will be looking to answer is whether or not increased deposits of amyloid-beta protein is a normal, healthy immune response that can be reversed when fighting infection.
Alzheimer’s disease is an incredibly complex disease, as evidenced by the sheer number of studies about it and the many different angles scientists take in trying to understand it — but every piece of research brings us a little closer to finding a way to stop it.
“Once you’re over 65, your risk factor really goes up, but we’re also looking for other causes, because it’s not just age — it’s environmental exposure as well,” says St. John.
“And we think bacteria and viruses are critical.”
The search was published in Scientific Reports.