Nose Picking and Dementia: A Possible Connection
A 2022 study suggests a potential link between nose picking and an increased risk of dementia. When picking your nose leads to internal tissue damage, certain bacteria may find a clearer route to the brain. This could trigger responses similar to those seen in Alzheimer’s disease.
But there are significant caveats. Most notably, the research has primarily been conducted on mice, not humans. Despite this, the findings could deepen our understanding of Alzheimer’s, a condition that still puzzles many researchers.
A group of scientists from Griffith University in Australia explored the effects of a bacterium known as Chlamydia pneumoniae, linked to human infections, including pneumonia. Strikingly, this bacterium has been found in many human brains affected by late-onset dementia.
In their experiments, they observed that in mice, the bacteria could ascend the olfactory nerve, the pathway connecting the nasal cavity to the brain. Moreover, when the nasal epithelium, a thin tissue, was damaged, the nerve infections worsened.
This situation resulted in higher levels of amyloid-beta protein in the mice brains—a substance released during infections. Plaques of this protein are commonly found in people diagnosed with Alzheimer’s disease.
“We are the first to demonstrate that Chlamydia pneumoniae can travel directly from the nose into the brain and potentially instigate Alzheimer’s-like pathologies,” said neuroscientist James St John, highlighting concerns about the implications for humans.
The rapidity with which C. pneumoniae infects the central nervous system surprised researchers, with observable infection occurring within just 24 to 72 hours. This suggests that bacteria and viruses may view the nose as a direct access point to the brain.
While it remains uncertain whether the same effects occur in humans—or even if amyloid-beta plaques are a causal factor in Alzheimer’s—it’s crucial to explore promising avenues in understanding this widespread neurodegenerative illness.
“We need to validate this pathway in human studies,” St John noted, emphasizing the necessity for further research. “We know these bacteria exist in humans, but we haven’t determined how they get there.”
Nose picking isn’t exactly an unusual habit—estimates suggest that up to 90% of people may engage in it. While the benefits of this behavior are not entirely clear, insights from this study might make us think twice before indulging.
Looking to the future, researchers plan to investigate similar processes in humans. Until then, St John and his team advise against nose picking and hair plucking due to possible damage to protective nasal tissue.
One significant question the team aims to tackle is whether the increased levels of amyloid-beta protein are a natural immune response that can be mitigated post-infection.
Alzheimer’s is a multifaceted disease, evidenced by numerous studies and varied approaches to understanding it. Each new piece of research helps inch closer to finding ways to combat this condition.
“Once you hit 65, your risk factors rise significantly, but we’re also considering other factors besides age, including environmental exposures,” St John elaborated. “Bacterial and viral influences are vital in this context.”
The findings were published in Scientific Reports.
