

Christmas time brings with it all sorts of long standing traditions, beliefs, celebrations and songs, but have you ever wondered about the truths and facts behind the magic of the festive holiday?

Researchers have discovered that there is scientific evidence that explains why Rudolph has a red nose.

Published in a journal on the British Medical Journal website, researchers in Norway and the Netherlands discovered that a reindeer’s nose is supplied with a large quantity of red blood cells that help protect the animal from freezing temperatures, as well as regulate brain temperature.

Known as ‘nasal microcirculation’, the tiny blood vessels, also known as micro-vessels, found in the nose, are vital for oxygenating the animal’s body, and controlling temperature and inflammation, but there hasn’t been much detailed studies conducted on their specific function.

The researchers set about to try and test to see whether Rudolph the reindeer’s infamous red nose was due to a “highly dense and rich nasal microcirculation” when compared with human noses.

Firstly, the researchers used a hand-held video microscope, and assessed the noses of five healthy human volunteers, by making them run on a treadmill to increase their heart rate and get their blood pumping. The researchers discovered that the blood circulating in the human volunteers’ nasal vessels had a density of 15mm/mm2.

ReindeerCredit: Morguefile

Because reindeer can be exposed to temperatures of -40 to -50 degrees Centigrade in Northern Norway, they have a heavy fur coat to insulate their bodies and regulate their core temperature. However, when they start to move, or run, they quickly become warm, and are unable to sweat to cool themselves like humans do. Instead they need a quick way to release the excess heat from their bodies. This is achieved through panting from their nose and mouth to increase the blood flow, hence ‘nasal microcirculation.’

When the test was applied to two reindeer, which also ran on a treadmill to increase their heart rate and get the blood moving around their body, the researchers discovered that there was a 25% higher density of blood vessels in a reindeer nose than a human nose, which carries a super-rich concentration of red blood cells.

Also in the reindeer noses, they found that there was a high density of mucous glands, which they suggest helps to "maintain an optimal nasal climate during changing weather conditions and extremes of temperature as well as being responsible for fluid transport and acting as a barrier."

Furthermore, infrared thermal images showed that when reindeer start exercising and moving, they do indeed have red noses. So it isn’t any wonder why Rudolph’s nose is so red - we would all be pretty flushed in the face if we had to pull Santa in a sleigh full of presents across the globe in one night.

Below is a link to a short video made by the researchers that shows the process of the test, as well as the infrared images of the reindeer’s red nose.