Scientists Reveal Why Rudolph Reindeer has a Red Nose

Scientists have found an explanation as to why Rudolph, Santa's lead reindeer pulling the sleigh through the night on Christmas Eve, has a red nose.

High functional density of blood vessels that carry oxygen-rich blood cells in the nose is the secret behind Rudolph's shiny red nose, according to a team of researchers from the Erasmus Medical Center in Rotterdam, the Netherlands, and the University of Rochester in New York.

For their study, the researchers used a technique of hand-held intravital video microscopy to compare the nasal microcirculation of two reindeer with that of the human nasal microvasculature. 

The study involved five healthy humans and one person with nasal polyps. One of the healthy volunteers was supplied 100 mg cocaine to test the vascular reactivity of the nasal mucosa. Nasal mucosa is exhibited by the nasal microcirculation. It plays a significant role in the uptake of drugs and responses to allergens. Cocaine drug is used in ear, nose, and throat medicine as a local anesthetic and vasoconstrictor.

Researchers further tested the nasal mucosa of the reindeer and found that the microcirculation carried a rich concentration of red cells, reports medpageToday.

They also made the reindeer to complete a treadmill test and analyzed their nasal microcirculation. A thermographic image of the reindeer's nose showed that they are red in color.

"In addition to the nose having a high microvascular density, the nasal mucosa also revealed an abundance of ring-like vascular arrangements, similar to those in humans," the researchers wrote in the paper.

They found that the functional vascular density of the reindeers' nasal mucosa was 25 percent more than that of humans. It protects the reindeer from freezing in cold temperatures and helps regulate their brain temperature. 

"The nasal microcirculation of reindeer is richly vascularised, with a vascular density 25 percent higher than that in humans. These results highlight the intrinsic physiological properties of Rudolph's legendary luminous red nose, which help to protect it from freezing during sleigh rides and to regulate the temperature of the reindeer's brain, factors essential for flying reindeer pulling Santa Claus's sleigh under extreme temperatures," the researchers wrote.

The findings of the study, "Why Rudolph's nose is red:observational study", are published in the British Medical Journal.