Ed note: Maybe some day we’ll get answers on dementia. This is one of many intriguing avenues of research. Could the amyloid in Alzheimer’s be a reaction to an infection spreading from the nose. There are some indications that this pathway occurs in mice, but how about humans? It’s nice to know that researchers are looking for all possibilities.
A study published in 2022 revealed a tenuous but plausible link between picking your nose and increasing the risk of developing dementia.
In cases where picking at your nose damages internal tissues, critical species of bacteria have a clearer path to the brain, which responds to their presence in ways that resemble signs of Alzheimer’s disease.
There are plenty of caveats here, not least that so far the supporting research is based on mice rather than humans, but the findings are definitely worth further investigation – and could improve our understanding of how Alzheimer’s gets started, which remains something of a mystery.
A team of researchers led by scientists from Griffith University in Australia ran tests with a bacterium called Chlamydia pneumoniae, which can infect humans and cause pneumonia.
The bacteria has also been discovered in the majority of human brains affected by late-onset dementia.
It was demonstrated that in mice, the bacteria could travel up the olfactory nerve (joining the nasal cavity and the brain). What’s more, when there was damage to the nasal epithelium (the thin tissue along the roof of the nasal cavity), nerve infections got worse.
This led to the mouse brains depositing more of the amyloid-beta protein – a protein which is released in response to infections. Plaques (or clumps) of this protein are also found in significant concentrations in people with Alzheimer’s disease. (continued)