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

Discussion in 'Health and Fitness' started by Frederick Foresight, Dec 7, 2022.

  1. https://www.cnn.com/2022/12/06/health/why-winter-colds-flu-wellness/index.html

    A chill is in the air, and you all know what that means — it’s time for cold and flu season, when it seems everyone you know is suddenly sneezing, sniffling or worse. It’s almost as if those pesky cold and flu germs whirl in with the first blast of winter weather.

    Yet germs are present year-round — just think back to your last summer cold. So why do people get more colds, flu and now Covid-19 when it’s chilly outside?

    In what researchers are calling a scientific breakthrough, scientists behind a new study may have found the biological reason we get more respiratory illnesses in winter. It turns out 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 virus and bacteria-fighting cells in the nostrils, according to the study published Tuesday 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 rhinologist Dr. Benjamin Bleier, director of otolaryngology 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.”

    A hornet’s nest
    To understand why this occurs, Bleier and his team and coauthorMansoor Amiji,who chairs the department of pharmaceutical sciences at Northeastern University in Boston, went on a scientific detective hunt.

    A respiratory virus or bacteria invades the nose, the main point of entry into the body. Immediately, the front of the nose detects the germ, well before the back of the nose is aware of the intruder, the team discovered.

    At that point, cells lining the nose immediately begin creating billions of simple copies of themselves called extracellular vesicles, or EV’s.

    “EV’s can’t divide like cells can, but they are like little mini versions of cells specifically designed to go and kill these viruses,” Bleier said. “EV’s act as decoys, so now when you inhale a virus, the virus sticks to these decoys instead of sticking to the cells.”

    Those “Mini Me’s” are then expelled by the cells into nasal mucus (yes, snot), where they stopinvading germs before they can get to their destinations and multiply.

    “This is one of, if not the only part of the immune system that leaves your body to go fight the bacteria and viruses before they actually get into your body,” Bleier said.

    Once created and dispersed out into nasal secretions, the billions of EV’s then start to swarm the marauding germs, Bleier said.

    “It’s like if you kick a hornet’s nest, what happens? You might see a few hornets flying around, but when you kick it, all of them all fly out of the nest to attack before that animal can get into the nest itself,” he said. “That’s the way the body mops up these inhaled viruses so they can never get into the cell in the first place.”

    A big increase in immune power
    When under attack, the nose increases production of extracellular vesicles by 160%, the study found. There were additional differences: EV’s had many more receptors on their surface than original cells, thus boosting the virus-stopping ability of the billions of extracellular vesicles in the nose.

    “Just imagine receptors as little arms that are sticking out, trying to grab on to the viral particles as you breathe them in,” Bleier said. “And we found each vesicle has up to 20 times more receptors on the surface, making them super sticky.”

    Cells in the body also contain a viral killer called micro RNA, which attack invading germs. Yet EVs in the nose contained 13 times micro RNA sequences than normal cells, the study found.

    So the nose comes to battle armed with some extra superpowers. But what happens to those advantages when cold weather hits?

    To find out, Bleier and his team exposed four study participants to 15 minutes of 40-degree-Fahrenheit (4.4-degree-Celsius) temperatures, and then measured conditions inside their nasal cavities.

    “What we found is that when you’re exposed to cold air, the temperature in your nose can drop by as much as 9 degrees Fahrenheit. And that’s enough to essentially knock out all three of those immune advantages that the nose has,” Bleier said.

    In fact, that little bit of coldness in the tip of the nose was enough to take nearly 42% of the extracellular vesicles out of the fight, Bleier said.

    “Similarly, you have almost half the amount of those killer micro RNA’s inside each vesicle, and you can have up to a 70% drop in the number of receptors on each vesicle, making them much less sticky,” he said.

    What does that do to your ability to fight off colds, flu and Covid-19? It cuts your immune system’s ability to fight off respiratory infections by half, Bleier said.

    You don’t have to wear a nose sock
    As it turns out, the pandemic gave us exactly what we need to help fight off chilly air and keep our immunity high, Bleier said.

    “Not only do masks protect you from the direct inhalation of viruses, but it’s also like wearing a sweater on your nose,” he said.

    Patel agreed: “The warmer you can keep the intranasal environment, the better this innate immune defense mechanism will be able to work. Maybe yet another reason to wear masks!”


    In the future, Bleier expects to see the development of topical nasal medications that build upon this scientific revelation. These new pharmaceuticals will “essentially fool the nose into thinking it has just seen a virus,” he said.

    “By having that exposure, you’ll have all these extra hornets flying around in your mucous protecting you,” he added.
     
    proftradingjourney likes this.
  2. That's why I wear a Kayne mask when I go out for a walk in the cold. LOL. Actually, I do wear a ski mask when it's below 20 degrees or so because sucking in cold air triggers my Afib.
     
  3. Still taking cold showers and doing the breathwork per WHM? If so, just curious for how long and at what water temperature? I used a meat thermometer to measure (on the water, not myself). It's just under 11C, which is under 52F. I'm good for a bit over 2 minutes. I expect the water will continue to get colder as the winter wears on. Fortunately, I started in the fall, so I have been acclimatizing myself to the assault of winter water.
     
  4. I am still doing the breathwork daily and have started up the cold showers again about 2 months ago after a good 6 month layoff. I take my warm shower as usual,then go to hot for about one minute. At that point I begin to dial back the temp towards cold which takes about one minute until it's full cold water. What that exact temp is I don't know. I stay in that 2 to 3 minutes. Sometimes that's it, sometimes I go back to hot for a minute or so. Just depends on my mood. Yes, the water will get colder in the winter and it's never something I am enthusiastic about which I think is the point. I do think it keeps my skin a bit tighter, but have no real measure for that
     
  5. I go from warm straight to full cold. It’s quite the waker-upper. I also wear a watch to make sure I remain in place for a full 2 minutes and 15 seconds. I have a sequence I follow to occupy my mind for the duration, and that’s how long it takes.

    I have a feeling that if I didn’t wear the watch I would overestimate the time I spent in there. Speaking of which, if anyone ever tells you that you have only 5 minutes to live, then I think you’ll agree that spending it in a cold shower will make it seem much, much longer.
     
    CaptainObvious likes this.
  6. Pekelo

    Pekelo

    Freaking scientists, they could have just asked me. In the winter:

    1. People spend more time indoors in close contact.
    2. Less vitamin D and generally less other vitamins too in the body.
    3. Thanksgiving, Christmas, New year's Eve, Superbowl all super spreader events.

    In Florida it is opposite, because of the summer heat people spend more time indoors in AC.
     
    Last edited: Dec 7, 2022
  7. Overnight

    Overnight

    What about folks in Africa who live at the equator, where it is as direct sunlight as you can get all year round (So vitamin D is not a problem), and never gets cold? Did they do a study on those folks?
     
  8. Pekelo

    Pekelo

    Apparently, they don't have a flu season:

    https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3324878/

    Q: Do African countries need the same level of flu vaccination as believed to be beneficial in non-tropical parts of the world?

    A: Most countries don’t have a clear idea of what the influenza disease burden is like. If you take the countries in sub-Saharan Africa, because they are located either side of the Equator, it’s difficult for them to decide which vaccine to choose: the northern hemisphere or the southern hemisphere.

    All this is based on having other competing health priorities like malaria, TB, HIV, and even if you look at just my country Ghana, for example, when you take the stats that are reported, you have ‘acute respiratory illness’ and within that category you can have broncho-pneumonia, pneumonia, severe pneumonia, but you don’t have a proportion attributable to influenza.

    Our expanded program of immunization has hitherto not considered rolling out an influenza vaccine.

    ...because many countries in Africa don’t know the burden of influenza.
     
  9. Overnight

    Overnight

    Right. So they don't know how many people there are dying from the flu, because they do not test for it.

    That is brilliant science. Let's just take that HIV research money and line our pockets, and not test for the flu. Let's not gather data on a disease that has killed millions of people over the past 100 years.

    Great science. Show me the money.
     
  10. Pekelo

    Pekelo

    I took it that it was not a significant threat there. It sure exists, but not on the endemic level and there is no seasonality to it. They have much bigger problems too.
     
    #10     Dec 8, 2022