Research confirms: People who love picking their noses are more likely to suffer from Alzheimer's disease!

What happens to people who pick their noses for a long time?

Countless public accounts have published articles on this topic, and the content can be summarized as follows: there is a risk of infection, a risk of bleeding, and the nostrils will not grow larger.

These views... are certainly not wrong.

But a paper published in Scientific Reports some time ago showed that picking your nose can actually increase the risk of Alzheimer’s disease, also known as senile dementia[1]. How could this be?

01

Alzheimer's disease is a global problem

Alzheimer's disease is more common in the elderly, and is a disease with memory impairment, cognitive impairment, and neurodegenerative lesions as its main symptoms. Patients generally begin to develop symptoms from a significant decline in memory function, gradually developing into multiple neurological disorders and loss of self-care ability.

Alzheimer's disease not only affects the patient's quality of life in his or her later years, but also brings more care pressure to his or her family.

Countless scientists around the world are working hard to conquer this disease, but the specific cause and pathogenesis are still unclear. Therefore, there is no cure for the disease, and we can only work on delaying the progression of the disease, alleviating some symptoms, and improving the quality of life.

Although the specific cause of the disease is unknown, the medical community has discovered some characteristic pathological phenomena.

The brains of patients will have diffuse neuritic plaques, extracellular amyloid deposition, neurofibrillary tangles, and hyperphosphorylated tau protein aggregation in cells. These characteristics provide direction and ideas for the study of the pathogenesis.

02

From nose picking to Alzheimer's

As the most characteristic pathological component of Alzheimer's disease, beta-amyloid is actually an antimicrobial peptide. [2] It is released by nerve cells in response to specific inflammatory factors . Alzheimer's patients have beta-amyloid deposits in their brains, which means that they have experienced a large amount of inflammatory response in their brains.

Naturally, scientists looked for answers along the lines of inflammation and infection.

Indeed, some studies have found that up to 90% of Alzheimer’s patients have residual Chlamydia pneumoniae DNA in their brains, while only about 5% of normal people have Chlamydia pneumoniae in their brains. [3-5]

It appears that Chlamydia pneumoniae is closely related to the onset of Alzheimer's disease.

Further research has found that Chlamydia pneumoniae can bypass the blood-brain barrier and directly invade the brain by infecting the olfactory nerve and trigeminal nerve. This can trigger a long-term inflammatory response, which can then induce or promote the onset of Alzheimer’s disease. [1] Therefore, if you pick your nose with dirty hands that carry a certain amount of pathogenic bacteria, Chlamydia pneumoniae may actually infect your brain, increasing the risk of developing Alzheimer’s disease!

03

Significance of this finding

For ordinary people, this discovery may not be good news.

An anonymous survey found that almost everyone picks their nose.

Most people pick their nose about four times a day, but a few may pick their nose more than six times a day. [6] The prevalence of nose picking means that everyone is at risk of being infected with Chlamydia pneumoniae, which increases the risk of developing Alzheimer’s disease.

But the solution is simple:

1. Pay attention to hygiene, clean your nose before picking it, and use clean and gentle tools to clean your nasal cavity. Even if you are not trying to prevent Alzheimer's disease, you should also prevent other sources of infection;

2. Be as gentle as possible to reduce damage to the nasal mucosa;

3. Maintain good indoor ventilation to reduce the concentration of pathogens in the environment, thereby reducing the risk of infection;

4. Pay attention to the air humidity to avoid excessive dryness of the nasal cavity, which may damage the barrier.

This discovery has special significance for medical staff and scientific researchers.

On the one hand, it reveals the relationship between Chlamydia pneumoniae and Alzheimer's disease, providing evidence and ideas for further research, treatment and prevention; on the other hand, the unique and rapid path of Chlamydia pneumoniae into the brain provides a new possibility for intracerebral medication. Some brain diseases are not lacking in effective drugs. However, due to the existence of the blood-brain barrier, drugs often cannot reach the location in the brain where they need to act.

For many years, scientists have been looking for drug carriers that can cross the blood-brain barrier, and the infection route of Mycoplasma pneumoniae may provide new possibilities for intra-brain drug administration.

Then again, since picking your nose is a sport that everyone loves, the absolute risk is not very high.

But if you pick it out and eat it, the risk will increase sharply.

Because it is very likely that you will be disliked by everyone, which will harm your mental health.

References:

[1] Chacko A, Delbaz A, WalkdenH, et al. Chlamydia pneumoniae can infect the central nervous system via theolfactory and trigeminal nerves and contributes to Alzheimer's disease risk. SciRep.2022;12(1):2759.Published 2022 Feb 17.doi:10.1038/s41598-022-06749-9

[2] Soscia SJ, Kirby JE, Washicosky KJ, et al. The Alzheimer's disease-associated amyloid beta-protein isan antimicrobial peptide.PLoS One. 2010;5(3):e9505.Published 2010 Mar 3.doi:10.1371/journal.pone.0009505

[3] Balin BJ, Gérard HC, ArkingEJ, et al. Identification and localization of Chlamydia pneumoniae in the Alzheimer's brain. Med Microbiol Immunol. 1998;187(1):23-42.doi:10.1007/s004300050071

[4] Schumacher HR Jr, Gérard HC, ArayssiTK, et al. Lower prevalence of Chlamydia pneumoniae DNA compared with Chlamydiatrachomatis DNA in synovial tissue of arthritis patients. Arthritis Rheum.1999;42(9):1889-1893.doi:10.1002/1529-0131(199909)42:9<1889::AID-ANR13>3.0.CO;2-W

[5] Balin BJ,Little CS,HammondCJ,et al.Chlamydophila pneumoniae and the etiology of late-onset Alzheimer'sdisease.J Alzheimers Dis. 2008;13(4):371-380. doi:10.3233/jad-2008-13403

[6] Andrade C, Srihari BS. Apreliminary survey of rhinotillexomania in an adolescent sample.J Clin Psychiatry.2001;62(6):426-431.doi:10.4088/jcp.v62n0605

Author｜Feidao Duanyu popular science author

Review｜Qiao Jiange, deputy chief nurse of geriatric department, Shanghai Fifth People's Hospital, Fudan University