Headline after headline has been written about a 2024 study, published in the scientific journal Biomolecules, which suggests that “neuroinflammation may also play an — at least partial — role in [Alzheimer’s] pathogenesis.”
The paper proposes that one factor that could cause this inflammation is “accidental exposure of the olfactory mucosa to hands contaminated with soil and faeces when picking one’s nose.”
Given that almost all of us admit to indulging in the admittedly gross habit from time to time, should we all be panicked about incoming dementia diagnoses?
Well, according to Dr. Zachary Rubin, a paediatrician, allergist, and immunologist, probably not.
Why not?
The paper itself doesn’t say that Alzheimer’s is caused by nose-picking ― it just suggests that the habit “may” lead to the introduction of pathogens that could, potentially, cause a condition linked to the disease.
Speaking in a TikTok video, the doctor revealed that the “study” the headlines refer to is actually a narrative review.
That means that it’s “not actually a prospective cohort study looking at groups of people who pick their nose commonly compared to those who don’t, and whether or not they develop Alzheimer’s later in life.”
He added that of the 55 million or so people diagnosed with Alzheimer’s right now, many of them tend to have amyloid beta plaques “as well as neurofibrillary tangles, which may be the result of chronic neuroinflammation” as the study says.
So yes, people who get more infections may be more likely to develop Alzheimer’s ― though it can be hard to distinguish correlation with causation there.
The authors of the study suggest that picking one’s nose “may” introduce the kind of bacteria that will, in the long term, cause inflammation that could eventually be linked to dementia ― but they don’t outright prove either that picking your nose leads to the kind of issues they’re referring to, or that those issues definitely cause Alzheimer’s.
So, while it’s good to remind people of the importance of washing their hands and limiting their nose-picking sessions where possible, the paper “does not prove that nose-picking causes Alzheimer’s,” Dr. Rubin suggests.
He’s not alone
Speaking to USA Today, Heather M. Snyder, Ph.D., vice president of medical and scientific relations at the Alzheimer’s Association said that there’s currently no definitive evidence of a cause-and-effect relationship between nose-picking and dementia.
However, she added, the study authors had tapped into an increasingly growing field of research.
“Increasingly, we know the immune system plays an important role in the underlying biology of Alzheimer’s – there are an increasing number of clinical trials targeting immune-related mechanisms,” she said.
It’s a good idea to wash your hands thoroughly before picking your nose, and it may be worth your while keeping the picking sessions to a minimum ― but until we have further evidence, you may be fine for the occasional nostril evacuation.