4 ms·

There is this old grandma theory that "don't run outside with wet hair, you'll catch a cold". Then we learned that viruses cannot spread like that, and so that

There is this old grandma theory that "don't run outside with wet hair, you'll catch a cold". Then we learned that viruses cannot spread like that, and so that old theory is basically invalid. But some time ago I read somewhere that this theory might still hold true somehow, because our nose stores all kinds of viruses, and they might burst out when we are weakened. Maybe someone more knowledgeable about this might chime in here ;).

kzrdude 5y ago
I think that saying is a bit unfairly mailgned. For making fire, there is the rule of three, the triangle, and you need all sides to keep combustion going: - Heat - Fuel - Oxygen knock one out and it falters. We should describe infections the same way. Needed for infection: - Virus/pathogen - Outer defenses penetration (skin/mucous membranes) - Immune system defeat Seeing it that way, it doesn't have to be so mysterious. Some viruses are dormant or almost omnipresent. The infection may be triggered by other conditions changing, including factors that affect your immune system status or efficiency of your outer protections!
AnxietyJello 5y ago
I thought the reasoning behind this saying was that when your body is cold your immune system needs to work harder to fend off Viruses and it was still true in that sense? Is that not the case?
roenxi 5y ago
The lesson in medical science is that being guided by anything short of actual evidence lets in a lot of pseudoscience. In this particular case; there might be a correlation but that doesn't tell us much. There are so many possible reasons even without asking an expert for possible explanations: 1) The atmosphere is in an unusual state (lots of fast moving water droplets, probably with a lot of backscatter as they hit the ground fast or bounce off leaves). Maybe bacteria use that as a travel mechanism. 2) Maybe an immune system defence is weakened by high humidity. 3) Maybe wet weather causes changes in behaviour unrelated to being wet, but that lead to higher disease transmission and the correlation is being misintepreted. 4) Maybe the bacteria really like rain and multiply like crazy when it is wet. 5) Maybe some people have an unrelated non-infectious illnesses that are triggered by the cold, damp weather and that is being misinterpreted as a cold. 6) Maybe grandmothers just say that because it seems like good advice and they don't like water being traipsed through the house. There are enough different options there that any correlation is not actionable. Leaving aside whether any correlation even exists.
astrobe_ 5y ago
The benign herpes virus "hides" in the body and can "surface" again from time to time. Wikipedia (I don't link cause unpretty images): "Worldwide rates of either HSV-1 or HSV-2 are between 60% and 95% in adults. HSV-1 is usually acquired during childhood. Rates of both increase as people age." "Following a primary infection, the virus enters the nerves at the site of primary infection, migrates to the cell body of the neuron, and becomes latent in the ganglion" "The causes of reactivation are uncertain, but several potential triggers have been documented. A 2009 study showed the protein VP16 plays a key role in reactivation of the dormant virus. Changes in the immune system during menstruation may play a role in HSV-1 reactivation. Concurrent infections, such as viral upper respiratory tract infection or other febrile diseases, can cause outbreaks. Reactivation due to other infections is the likely source of the historic terms 'cold sore' and 'fever blister'. Other identified triggers include local injury to the face, lips, eyes, or mouth; trauma; surgery; radiotherapy; and exposure to wind, ultraviolet light, or sunlight."
lordnacho 5y ago
Isn't this how shingles / chickenpox works?
loceng 5y ago
The body's immune system may be keeping viruses in check, in part why after the COVID mRNA vaccine there's been a reported uptick of other viruses being able to take hold - e.g. bypassing and brute forcing to overly focus on directions of mRNA seems to have unintended consequences, and I'm also curious how or if these "unrelated" illnesses were observed for and kept track of in the official clinic trials or not.
usrusr 5y ago
In sports, there's a parallel to the old grandma theory that is usually called the "open window theory" (somewhat difficult to google in english, much easier in german where the english term "open window" only exists as a loan word for this particular meaning) which says that after a tough training, some defenses aren't as strong as they usually are. That theory is not entirely uncontested, but if it holds some truth the same mechanism could very well be at play in the wet hair scenario. (Note how even your wording of the grandma theory is surprisingly in line with infection principles: the wet hair makes you "catch" a cold, from someone else, not directly causing the cold)

kzrdude 5y ago

I think that saying is a bit unfairly mailgned. For making fire, there is the rule of three, the triangle, and you need all sides to keep combustion going: - Heat - Fuel - Oxygen knock one out and it falters. We should describe infections the same way. Needed for infection: - Virus/pathogen - Outer defenses penetration (skin/mucous membranes) - Immune system defeat Seeing it that way, it doesn't have to be so mysterious. Some viruses are dormant or almost omnipresent. The infection may be triggered by other conditions changing, including factors that affect your immune system status or efficiency of your outer protections!

AnxietyJello 5y ago

I thought the reasoning behind this saying was that when your body is cold your immune system needs to work harder to fend off Viruses and it was still true in that sense? Is that not the case?

roenxi 5y ago

The lesson in medical science is that being guided by anything short of actual evidence lets in a lot of pseudoscience. In this particular case; there might be a correlation but that doesn't tell us much. There are so many possible reasons even without asking an expert for possible explanations: 1) The atmosphere is in an unusual state (lots of fast moving water droplets, probably with a lot of backscatter as they hit the ground fast or bounce off leaves). Maybe bacteria use that as a travel mechanism. 2) Maybe an immune system defence is weakened by high humidity. 3) Maybe wet weather causes changes in behaviour unrelated to being wet, but that lead to higher disease transmission and the correlation is being misintepreted. 4) Maybe the bacteria really like rain and multiply like crazy when it is wet. 5) Maybe some people have an unrelated non-infectious illnesses that are triggered by the cold, damp weather and that is being misinterpreted as a cold. 6) Maybe grandmothers just say that because it seems like good advice and they don't like water being traipsed through the house. There are enough different options there that any correlation is not actionable. Leaving aside whether any correlation even exists.

astrobe_ 5y ago

The benign herpes virus "hides" in the body and can "surface" again from time to time. Wikipedia (I don't link cause unpretty images): "Worldwide rates of either HSV-1 or HSV-2 are between 60% and 95% in adults. HSV-1 is usually acquired during childhood. Rates of both increase as people age." "Following a primary infection, the virus enters the nerves at the site of primary infection, migrates to the cell body of the neuron, and becomes latent in the ganglion" "The causes of reactivation are uncertain, but several potential triggers have been documented. A 2009 study showed the protein VP16 plays a key role in reactivation of the dormant virus. Changes in the immune system during menstruation may play a role in HSV-1 reactivation. Concurrent infections, such as viral upper respiratory tract infection or other febrile diseases, can cause outbreaks. Reactivation due to other infections is the likely source of the historic terms 'cold sore' and 'fever blister'. Other identified triggers include local injury to the face, lips, eyes, or mouth; trauma; surgery; radiotherapy; and exposure to wind, ultraviolet light, or sunlight."

lordnacho 5y ago

Isn't this how shingles / chickenpox works?

loceng 5y ago

The body's immune system may be keeping viruses in check, in part why after the COVID mRNA vaccine there's been a reported uptick of other viruses being able to take hold - e.g. bypassing and brute forcing to overly focus on directions of mRNA seems to have unintended consequences, and I'm also curious how or if these "unrelated" illnesses were observed for and kept track of in the official clinic trials or not.

usrusr 5y ago

In sports, there's a parallel to the old grandma theory that is usually called the "open window theory" (somewhat difficult to google in english, much easier in german where the english term "open window" only exists as a loan word for this particular meaning) which says that after a tough training, some defenses aren't as strong as they usually are. That theory is not entirely uncontested, but if it holds some truth the same mechanism could very well be at play in the wet hair scenario. (Note how even your wording of the grandma theory is surprisingly in line with infection principles: the wet hair makes you "catch" a cold, from someone else, not directly causing the cold)