New research on why people get colds in the winter: cold noses!

[Rebeccare]

I was just reading about a fascinating study in which scientists theorize that the temperature of your nose explains why people tend to get more colds when it's cold out: https://hms.harvard.edu/news/why-upper-respiratory-infections-are-more-common-colder-temperatures

The key is an element of our immune system within our noses that helps protect us against inhaled pathogens:

a 2018 study led by Bleier and Mansoor Amiji, Distinguished Professor of Pharmaceutical Sciences at Northeastern University, uncovered an innate immune response triggered when bacteria are inhaled through the nose. Cells in the front of the nose detected the bacteria and then released billions of tiny fluid-filled sacs called extracellular vesicles, or EVs, into the mucus to surround and attack the bacteria. Bleier, director of otolaryngology translational research at Mass Eye and Ear, compares the release of this EV swarm to “kicking a hornets’ nest.”

The 2018 study also showed that the EVs shuttle protective antibacterial proteins through the mucus from the front of the nose to the back along the airway, which then protects other cells against the bacteria before they get too far into the body.

In a study which was just published, scientists looked at how the temperature of the nose affected this response. They found that the immune response was greatly reduced in people who had been in colder weather for a relatively short amount of time:

The researchers then tested how colder temperatures affected this response, which is especially relevant in nasal immunity given that the internal temperature of the nose is highly dependent on the temperature of the outside air that is inhaled through it. They took healthy volunteers from a room temperature environment and exposed them to 39.9 F (4.4 C) temperatures for 15 minutes and found that the temperature inside the nose fell by about 41 F (5 C). They then applied this reduction in temperature to the nasal tissue samples and observed a blunted immune response. The quantity of EVs secreted by the nasal cells decreased by nearly 42 percent and the antiviral proteins in the EVs were also impaired.

Interestingly enough, this makes a good case for masking that has nothing to do with blocking out viruses or bacteria: wearing a mask helps keep the nose nice and warm, which helps ensure that the immune response remains robust. Speaking for myself, for the past year I've been wearing a mask outside whenever it's below 40F simply because it makes my nose and cheeks feel like they're wearing a warm winter coat!

 

[keepontruckin]

I wonder if this could help explain why my daughter's pain gets worse as the fall comes in with cooler weather. Her immune system is not as robust then . But her pain gets better in the spring.

 

[Wishful]

Speaking for myself, for the past year I've been wearing a mask outside whenever it's below 40F

There's a problem with that for those of us who wear glasses: they fog up. When I had to wear a mask last winter, there were times when I simply couldn't see where I was walking. Very inconvenient.

FWIW, somewhere below -35C, glasses start frosting up, which is even more annoying, since fog will evaporate on its own if you change where your breath goes, or have a breeze.

 

[Rufous McKinney]

There's a problem with that for those of us who wear glasses: they fog up.

if you have Sjogren's- your eyes are screwed. I am not operational in a mask. Makes me get real ill very very quickly and then yes of course the fog up.

 

[Wishful]

Here's an idea for someone to develop: masks that block the moist air from going up to the glasses. Find some way that doesn't look too ridiculous, please.

 

[BrightCandle]

If you use a N95/FP3 mask they seal all the way around and thus when fitted correctly do not leak air into your glasses, so you don't steam up. If you do steam up there is a fitting issue. There are also commercial reusable masks now like Flo that have filters that should reach N99 standards (haven't yet been approved tested) that seal with silicone and hence get a nice tight seal that fits well and all air goes through the filter.

 

[Nord Wolf]

Interesting. I'm not sure it explains why so many people in warmer climates (places that tend to get very mild or no real winter) also get the common cold seemingly as much as people in colder climates.

 

[Rufous McKinney]

If you use a N95/FP3 mask they seal all the way around and thus when fitted correctly do not leak air into your glasses, so you don't steam up.

it happens every time I wear one, despite tightening the metal brackets.

 

[Nord Wolf]

If people are just concerned about keeping their noses and airways warm during winter, why deal with masks at all? What happened to the good olde fashioned scarf? They keep the neck warm as well as the lower face, and they don't look absurd. They also breathe better than masks. For anyone not smooth shaven a mask seal is useless anyway... no matter how tight fitting. But nothing beats a scarf for keeping the lower face and neck warm in the cold And if this article holds any truth, a scarf will allow the old nose to do its germ killing job by keeping it warm.

 

[Wishful]

I'm not sure it explains why so many people in warmer climates (places that tend to get very mild or no real winter) also get the common cold seemingly as much as people in colder climates.

One possibility: in cold air, the mucus droplets freeze or evaporate and possibly inactivate the virus, while in warm air, they linger longer.