A New Alzheimer’s Risk Factor May Have Been Uncovered: Nose-Picking

When you were a child, your parents or teachers may have gently reminded you not to pick your nose. Despite these admonitions, many people continue this activity into later life. It turns out those adults may have been onto something, though. Avoiding the activity may be better for your brain, according to a new study.

Research recently published in the journal Biomolecules investigated whether nose-picking may contribute to neuroinflammation linked to Alzheimer’s. The research team, from Western Sydney University, say that while amyloid beta protein is one of the hallmarks of the disease, there is strong evidence that neuroinflammation may be linked to amyloid plaque formation.

This neuroinflammation may be helped along by viruses and bacteria entering the body through the nose and olfactory system, which has a close link to the brain and plays a role in early Alzheimer’s. Past research has found that viral infections may impact the olfactory system in such a way that accelerates Alzheimer’s.

At the same time, research has linked a variety of pathogens with Alzheimer’s, including herpes simplex virus type 1, the chickenpox-causing varicella zoster virus, and Chlamydia pneumoniae, which causes pneumonia and bronchitis. These can lead to chronic infections in areas like the nasal epithelium before ultimately moving to the brain.

The study authors write, “While the exact triggers of neuroinflammation in AD remain under discussion, recent evidence suggests that infectious agents, such as viruses, fungi, and bacteria, may play a role in causing neuroinflammation and the accumulation of senile plaques and neurofibrillary tangles. More recently, even COVID-19 has also been linked to cognitive decline in infected patients. The olfactory system presents an intriguing target for investigation due to its proximity to the brain and its early involvement in AD progression.”

So how may these viruses get into the olfactory system? The researchers say nose-picking could be one culprit, if the finger in question is contaminated. The behavior is often instinctive, however, undertaken subconsciously to clear out a nasal obstruction.

In the paper, the team showed that people who pick their noses were more apt to have certain harmful pathogens in their nasal area, which could later find their way into the central nervous system. The researchers pointed to studies showing nosepickers were more to have Staphylococcus aureus and S. aureus in their nostrils, and that they were more apt to contract COVID-19, which primarily gets into the body through the nasal mucous membrane.

Due to these separate areas of research, the team believes that neuroinflammation might be caused in part by pathogens entering the brain through the olfactory system.

They write, “Understanding the potential role of olfactory pathogen entry in AD-associated neuroinflammation opens up new avenues for prevention. Among all the entry routes, the improvement of hand hygiene might be an easy prevention step, as learned from the COVID-19 epidemic. One of the lessons learned from COVID-19 is the value of hand hygiene through frequent hand washing and the use of hand sanitizers, and we suggest these routine hygienic procedures be mandatory routine procedures for the incurable nose-picker.”

So before you clear something out of your nostril after reading this story, you may want to head over to the sink first.