A study published in 2022 revealed a subtle but plausible link between nose picking and an increased risk of dementia.
If nose picking damages internal tissue, key species of bacteria would have a clearer path to the brain, and the brain would respond to their presence in ways similar to Alzheimer’s symptoms.
There are a lot of caveats here, not least that the supporting studies so far are based on mice rather than humans, but the findings definitely deserve further study — and could improve our understanding of how Alzheimer’s disease begins, which remains a mystery.
A team of researchers led by scientists from Australia’s Griffith University tested a type of bacteria called Chlamydia pneumoniaewhich can infect humans and cause pneumonia.
The bacteria are also found in the brains of most people with late-onset dementia.
Research shows that in mice, bacteria can spread along the olfactory nerves that connect the nose to the brain. What’s more, nerve infections can become more severe when the nasal epithelium (the thin tissue at the top of the nasal cavity) is damaged.
This caused the mice’s brains to deposit more beta-amyloid—a protein released in response to infection. Plaques (or clumps) of this protein are also found in high concentrations in Alzheimer’s patients.
“We are the first to prove this Chlamydia pneumoniae James St John, a neuroscientist at Griffith University in Australia, said as early as October 2022 when the study was released:
“We see this happening in mouse models, and the evidence could be scary in humans as well.”
Scientists surprised by its speed Chlamydia pneumoniae The virus takes hold in the mice’s central nervous system, and infection occurs within 24 to 72 hours. Bacteria and viruses are thought to use the nose as a quick route to the brain.
While it’s uncertain whether these effects are the same in humans, or even whether beta-amyloid plaques are a cause of Alzheimer’s disease, there are still promising clues to follow in the fight to understand this common neurodegenerative disease. Very important.
“We need to do this study in humans and confirm whether the same pathways operate in the same way,” St. John said.
“This is research that many people have proposed, but it hasn’t been done yet. What we know is that these same bacteria are present in humans, but we haven’t figured out how they get there.”
Picking your nose is not an uncommon thing. In fact, it’s possible that as many as 9 out of 10 humans do this… not to mention many other species (some more adept than others). While the benefits aren’t yet clear, studies like this should give us pause before making a choice.
Future studies of the same process in humans are planned, but until then, St. John and his colleagues believe that picking noses and plucking nose hairs is “not a good idea” because of the damage it can cause to protective nasal tissue.
One outstanding question the team hopes to answer is whether the increase in beta-amyloid deposits is a natural, healthy immune response that can be reversed when the infection is fought off.
Alzheimer’s is an extremely complex disease, as is clear from the vast amount of research done on it and the different angles scientists try to understand it from, but each study brings us closer to finding ways to stop it method.
“Once you get over 65, your risk factors go way up, but we’re looking at other causes as well because it’s not just age, it’s environmental exposure,” St. John said.
“We think bacteria and viruses are critical.”
The study was published in scientific report.
A version of this article was first published in November 2022.
