Mouse study suggests surprising link between nose picking and Alzheimer’s disease: ScienceAlert
A new study has found a weak but plausible link between nose picking and an increased risk of developing dementia.
In cases where nose picking damages internal tissues, critical types of bacteria have a clearer path to the brain, which responds to their presence in signal-like ways Alzheimer’s disease disease.
There are quite a few caveats here, not only that the research so far is based on mice, not humans, but the findings are definitely worth further investigation – and could improve our understanding of how Alzheimer’s disease begins, which remains something of a mystery.
A team of researchers led by scientists from Griffith University in Australia conducted tests with bacteria called Chlamydia pneumoniaewhich can infect people and cause pneumonia. Bacteria have also discovered in most human brains affected by late-onset dementia.
It has been shown that in mice bacteria can travel along the olfactory nerve (connecting the nasal cavity and the brain). Moreover, when the nasal epithelium (the thin tissue lining the roof of the nasal cavity) was damaged, the nerve infections worsened.
This caused the mice’s brains to deposit more amyloid-beta protein – a protein released in response to infections. Plaques (or clumps) of this protein are also found in significant concentrations in the people with Alzheimer’s disease.
“We are the first to show it Chlamydia pneumoniae it can go directly into the nose and into the brain where it can trigger pathologies that look like Alzheimer’s disease,” says neuroscientist James St John from Griffith University in Australia.
“We’ve seen this happen in a mouse model, and the evidence is potentially frightening for humans as well.”
Scientists were surprised at the speed with which C. pneumoniae occupied the central nervous system of mice, and infection occurred within 24 to 72 hours. It is believed that bacteria and viruses sees the nose as a fast way to the brain.
Although it is not certain that the effects will be the same in humans, or even that amyloid-beta plaques are the cause of Alzheimer’s diseasehowever, it is important to pursue promising leads in the fight to understand this common neurodegenerative condition.
“We need to do this study in humans and confirm if the same pathway works in the same way,” says Saint John.
“That’s research that’s been proposed by a lot of people, but it’s not done yet. What we know is that these same bacteria are present in humans, but we haven’t worked out how they get there.”
Picking your nose is not a very rare thing. Actually, it is possible even 9 out of 10 people do it… not to mention a bunch of other kinds (some a little more skilled but others). Although the benefits are not clear, studies like this should give us pause before choosing.
Future studies of the same processes in humans are planned – but until then, St John and his colleagues suggest that nose picking and nose hair pulling are “not a good idea” because of the potential damage to the nose’s protective tissue.
One outstanding question the team will seek to answer is whether the increased deposits of amyloid-beta protein are a natural, healthy immune response that can be reversed when the infection is controlled.
Alzheimer’s is an incredibly complicated disease, as is clear from a huge number of studies in him and many different angles scientists are trying to understand it – but each study brings us a little closer to finding a way to stop it.
“Once you’re over 65, your risk factor goes up, but we’re also looking at other causes, because it’s not just age – it’s also environmental exposure,” says Saint John.
“And we think bacteria and viruses are critical.”
The research was published in Scientific reports.