Why Do We Get Colds in Winter?

As someone who spent the month before last Christmas suffering from a bad case of tonsillitis, the fear of getting ill and not being able to taste my Christmas dinner is a very real one. Many of us have this same worry, and at the moment it seems like every other person we speak to complains of “feeling a bit ill” or “just getting over a cold”, prompting us to quickly take a step backward and refrain from shaking their hand (or maybe I’m the only one rude enough to actually do that).

Both the common cold and the flu seem to be more prevalent in the winter months, just in time for Christmas. While it is still fairly unclear why this is, these are a couple of possible explanations for this sniffly season:

As the temperature gets colder, we tend to spend more time in confined spaces to keep out of the cold. This is likely to increase the ease of the virus spreading, as people are in close confinement, so we’re more likely to inhale droplets containing the virus when an infected person sneezes or coughs

Decreased sunlight hours decrease the amount of UV light emitted by the sun. UV light damages DNA of viruses, making them less harmful, so in the winter when there is less UV light, viruses are more likely to survive and be passed on.

Children return to school in the Autumn. Because children have not encountered cold and flu viruses, they are more at risk from catching them. While the average adult will catch 2-4 colds per year, children are likely to catch 6-8. So when children return to school and mix with other children, they pick up colds and from there they can be passed onto their parents.

So how can we defend ourselves from a cold this winter?

“Drink a glass of orange juice,” is the usual response, but recent studies show that increased consumption of vitamin C does not decrease the general population’s chances of catching a cold. Vitamin C has however been seen to boost immunity in people undertaking intensive physical exercise. Skiers, marathon runners and soldiers are some of the groups of people whose immunity would benefit from increased vitamin C, as it can cut their occurrence of colds in half.

Studies at Carnegie Mellon University in Pennsylvania found that interacting with a diverse social network can decrease your chance of catching a cold. Participants who had interacted recently with a range of people (mixture of colleagues, parents, neighbours, spouses and other categories) were less likely to develop symptoms of a cold after having Rhinovirus (the virus which causes 40% of colds) squirted up their nose (gross, right?) than those who had only interacted with three or less of those categories.

Another study conducted at the same university found that positive, happy people are less likely to suffer from colds. They studied 300 helathy volunteers and interviewed them over two weeks to find out their emotional state. The scientists then squirted Rhinovirus up participants’ noses and interviewed them over the next few days about their symptoms. People who were in the bottom third for having positive emotions were three times as likely to get a cold than those in the most positive third. This may be because happier people tend to lead healthier lifestyles and have lower blood levels of the stress hormone cortisol, high levels of which have been linked to low immunity.

So keep your chin up, and maybe you’ll be able to taste your turkey this Christmas.

Humans aren’t the only ones who might be exchanging gifts this Christmas: read my latest article for Redbrick.

As always, please feel free to comment.


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