A lot of you may have seen a news story going around saying "Oh hey it turns out that being out in the cold CAN make you catch cold, your Mom was right all along"
This is a great example of non-scientific reporting/skewing of scientific facts because hey neat headline.
Background: I do infectious disease research with the Canadian
government and while I have NO background in rhinovirus infections, I'm
able to at least look at the original work and understand the findings a
bit better than the average bear.
I just read the original research paper, here are some things to consider:
-The virus in question is well known to grow better at regular nose
temperature (33°C) as opposed to internal body temperature (37°C). This
is a long established fact and is not news
-The reason cold
viruses infect the nose and only rarely the lungs is specifically due to
this temperature difference. HOWEVER, the nose is 33°C when you're
sitting around hanging out in the office, outside on a normal day, etc.
That's the regular temperature of a wet surface that has air constantly
blowing over it. So regardless of what time of year it is, your nose
will likely be around 33°C. It may be somewhat colder if you spend a
prolonged period of time outside, but this paper does not address what
happens when a virus is exposed to temperatures colder than 33°C.
-The study was not trying to answer the question "Does cold weather
make the common cold more contagious or severe", they were trying to
answer the question "What is the cause of improved viral replication at
33°C, which is the normal temperature of the inside of a nose" - the
answer was that it's a reduced immune response on the part of the host
that contributes to enhanced viral replication. This isn't really
newsworthy either. A lot of your body's functions will be impaired at
33°C, including the immune system. This is already well-known anyway,
but this paper elucidated the precise mechanism by which the impairment
happens. Interesting to scientists but boring to the general public.
-The study was done in mouse trachea cells in a petri dish using a
specially mutated virus that's been enhanced to grow better in mouse
cells. It took 5-7 hours to see a difference in viral titers between the
two temperatures tested. These conditions aren't even close to what
happens when humans catch a cold. This is fine, most animal infection
models don't match human conditions.
Please don't read this as "I
guess it's true after all, you DO catch a cold because of cold
weather". Whether or not THAT is true, it's not even CLOSE to what this
research paper is stating.
For shits and giggles, here's a link to the research paper (pdf download). Enjoy