Scientists finally know why people get more colds and flu in winter!

[TNtoTaos]

OMG -- our Grannies were right, but not for the reason they all thought! This is a fascinating article! Time to get those masks out again, everyone!
Scientists finally know why people get more colds and flu in winter

 

[racetiger]

Why?
(My phone won't let me read the link.)

 

[contesstant]

Interesting for sure!

 

[marzNC]

This seems to be the key point. The study was reported in 2022 based on lab work with a few volunteers.

" . . .
In what they called a “breakthrough,” scientists uncovered the biological reason we get more respiratory illnesses in winter — the cold air itself damages the immune response occurring in the nose.

“This is the first time that we have a biologic, molecular explanation regarding one factor of our innate immune response that appears to be limited by colder temperatures,” said rhinologist Dr. Zara Patel, a professor of otolaryngology and head and neck surgery at Stanford University School of Medicine in California. She was not involved in the new study.

In fact, reducing the temperature inside the nose by as little as 9 degrees Fahrenheit (5 degrees Celsius) kills nearly 50% of the billions of helpful bacteria-fighting cells and viruses in the nostrils, according to the 2022 study published in The Journal of Allergy and Clinical Immunology.

“Cold air is associated with increased viral infection because you’ve essentially lost half of your immunity just by that small drop in temperature,” said study author Dr. Benjamin Bleier, director of otolaryngology translational research at Massachusetts Eye and Ear and an associate professor at Harvard Medical School in Boston.

“it’s important to remember that these are in vitro studies, meaning that although it is using human tissue in the lab to study this immune response, it is not a study being carried out inside someone’s actual nose,” Patel said in an email. “Often the findings of in vitro studies are confirmed in vivo, but not always.”
. . ."

 

[Olesya Chornoguz]

Thank you for sharing @TNtoTaos - very interesting. I went to read the original research article abstract in the Journal of Allergy and Clinical Immunology. I am a Ph.D. immunologist working in cancer immunology with 10+ years of experience post Ph.D. so I was very curious to understand a bit more of the article.

Couple of things:
This is an in vitro study - they took cells from people's noses and put them in a dish, so this may or may not fully represent what happens in human nose. It is a very cool study nevertheless and it is a very novel scientific finding - very exciting!

The main point that I took away from the abstract of the original research article is that cells of intranasal mucosa (cells that line our noses) secrete a bunch of extracellular vesicles (EV, tiny balls of fat with cargo inside) when exposed to viruses. The cargo in these EV is what inactivates the viruses. When it is cold the cells of intranasal mucosa secrete much less of the EV with the virus killing cargo, thus less protection from the viral infection in the colder temps. Hope that makes sense, happy to explain more if anyone has any questions.

 

[TNtoTaos]

This is an in vitro study - they took cells from people's noses and put them in a dish, so this may or may not fully represent what happens in human nose. It is a very cool study nevertheless and it is a very novel scientific finding - very exciting!

Yes, and they were clear about that. Certainly much more in vivo research needs to be done to expand upon these findings and see if the results hold up. But as you say, it's a very exciting finding that opens up an entirely new avenue to pursue.

The main point that I took away from the abstract of the original research article is that cells of intranasal mucosa (cells that line our noses) secrete a bunch of extracellular vesicles (EV, tiny balls of fat with cargo inside) when exposed to viruses. The cargo in these EV is what inactivates the viruses. When it is cold the cells of intranasal mucosa secrete much less of the EV with the virus killing cargo, thus less protection from the viral infection in the colder temps.

Exactly, and I thought it was especially relevant to those of us who exercise and socialize in the cold, as I, for one, always considered us to be less likely to spread and catch viruses from one another in the "great outdoors", LOL. Maybe not, eh?

But another point that I took from it is that perhaps we should be more diligent about wearing masks outdoors; while this is all very preliminary, keeping our noses warm outdoors is an easy and harmless behavior that might pay off in the long run. Food for thought...

Glad to hear your comments @Olesya Chornoguz -- I was interested in what you'd have to say!

 

[marzNC]

But another point that I took from it is that perhaps we should be more diligent about wearing masks outdoors; while this is all very preliminary, keeping our noses warm outdoors is an easy and harmless behavior that might pay off in the long run. Food for thought...

For keeping my nose warm, the Face Saver that keeps my cheeks and nose warm without covering my mouth is what I use when skiing pretty much all the time.

 

[MissySki]

Thank you for sharing @TNtoTaos - very interesting. I went to read the original research article abstract in the Journal of Allergy and Clinical Immunology. I am a Ph.D. immunologist working in cancer immunology with 10+ years of experience post Ph.D. so I was very curious to understand a bit more of the article.

Couple of things:
This is an in vitro study - they took cells from people's noses and put them in a dish, so this may or may not fully represent what happens in human nose. It is a very cool study nevertheless and it is a very novel scientific finding - very exciting!

The main point that I took away from the abstract of the original research article is that cells of intranasal mucosa (cells that line our noses) secrete a bunch of extracellular vesicles (EV, tiny balls of fat with cargo inside) when exposed to viruses. The cargo in these EV is what inactivates the viruses. When it is cold the cells of intranasal mucosa secrete much less of the EV with the virus killing cargo, thus less protection from the viral infection in the colder temps. Hope that makes sense, happy to explain more if anyone has any questions.

@Olesya Chornoguz does the original article discuss how long the cells are impacted or how long it takes to get back to full strength after a cold temperature exposure?

 

[TNtoTaos]

@Olesya Chornoguz does the original article discuss how long the cells are impacted or how long it takes to get back to full strength after a cold temperature exposure?

Good question. @Olesya Chornoguz is the article in J Clint All & Immun behind a paywall?

 

[Olesya Chornoguz]

Yes, and they were clear about that. Certainly much more in vivo research needs to be done to expand upon these findings and see if the results hold up. But as you say, it's a very exciting finding that opens up an entirely new avenue to pursue.

Exactly, and I thought it was especially relevant to those of us who exercise and socialize in the cold, as I, for one, always considered us to be less likely to spread and catch viruses from one another in the "great outdoors", LOL. Maybe not, eh?

But another point that I took from it is that perhaps we should be more diligent about wearing masks outdoors; while this is all very preliminary, keeping our noses warm outdoors is an easy and harmless behavior that might pay off in the long run. Food for thought...

Glad to hear your comments @Olesya Chornoguz -- I was interested in what you'd have to say!

Yes, they were clear about that it is in vitro research. I wanted to reiterate it.

I will not be wearing a mask outdoors, it is rare to be in crowded settings outdoors and I don't think I have ever gotten sick from being outdoors, even around other people. I think most transmission happens indoors, as one comes indoors from the cold and the temperature inside the nose is lower for a bit still that is maybe when the transmission is happening. I have anecdotal examples about transmission indoors, though do not have statistics, so that is a hypothesis.

Another open question that @MissySki mentioned is how long does this effect last after cold exposure? The abstract pf the article doesn't give an answer to that. For example, if the effect lasts for hours after the cold exposure, then again transmission of viruses most likely happens indoors. Again, this is a potential hypothesis.

@MissySki the article is behind the paywall, I only read the abstract. I may be able to get the access to the full version later at work and look at how long the effect of the cold exposure lasts.

 

[mustski]

Can I just add… I love all the smart ladies on this site! Following the discussion!

 

[Bookworm]

I wonder if my little nose is overcompensating by sending so much liquid out when its cold. When i bend my head down, "water" literally runs out.