ANN/THE STAR – The nose really does know, as it turns out.
New research has revealed a physical link between chilly weather and the severity of colds, and it’s right under – or rather, inside – our noses.
Researchers at the Massachusetts Eye and Ear hospital and Northeastern University in the United States have discovered an immune response inside the nose that fights incoming infections – when it is warm enough.
The organ is a formidable frontline defender against the common cold and a host of other pathogens, except during cold weather, they said in a study published recently in the Journal of Allergy and Clinical Immunology.
“Conventionally, it was thought that cold and flu season occurred in cooler months because people are stuck indoors more where airborne viruses could spread more easily,” said study senior author and Massachusetts Eye and Ear Otolaryngology Translational Research director Dr Benjamin Bleier in a statement.
“Our study, however, points to a biological root cause for the seasonal variation in upper respiratory viral infections we see each year, most recently demonstrated throughout the COVID-19 pandemic.”
We inhale pathogens through our nose, or rub our nose and transfer germs from our hands to our nasal passages.
Then they work their way deeper into the body.
The researchers built on the findings of an earlier study done in 2018, which determined that cells at the front of the nose release billions of “extracellular vesicles” (EVs) – tiny sacs filled with fluid – that swarm the invaders.
“It’s akin to if you kick a hornets’ nest and all the hornets come out and attack,” Dr Bleier said.
The 2018 experiment was done on bacteria.
For the current study, Northeastern University Distinguished Professor of Pharmaceutical Sciences and Chemical Engineering Dr Mansoor Amiji tried it on viruses.
He then took it a step further, studying the effects of temperature on this immune response.
Using cultured cells from volunteers, the team found that the number of EVs dropped when the temperature inside the nose went down by as little as nine degrees.
With fewer EVs to bind to the virus particles and prevent entry, it was easier for an infection to root.
The researchers are hoping to use this information to beef up immunity or treat upper respiratory infections.
They also noted that wearing face masks can help by keeping the inside of the nose warm.