Ever wonder why you get more colds when it’s cold?
New research from Yale University School of Medicine has identified a scientific reason that has nothing to do with the fact that we’re spending more time indoors surrounded by those who are coughing and sneezing on us — a common explanation provided by infectious disease experts.
It turns out it may have to do with the frigid air that accosts our nostrils and turns our noses red.
The Yale researchers studied how common rhinoviruses, responsible for most colds, interact with mouse cells at a cooler temperature of 91 degrees Fahrenheit compared with our core body temperature of 99 degrees; they found that while the rhinoviruses behaved the same at both temperatures, immune cells aren’t as good at fending off the invaders at cooler temperatures, according to the study published this month in the Proceedings of the National Academy of Sciences.
While the study needs to be replicated in humans, study co-author and Yale immunobiologist Akiko Iwasaki said immune cells in the nose seem to lose their ability to sense viruses and alarm other cells to ready themselves for combat. “Taking away this sensor and alarm from the immune system probably enables the cold virus to replicate more readily when the nose is chilled,” she said.
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By dividing and spreading in the cooler nose, rhinoviruses likely evolved to have an advantage over more dangerous respiratory viruses like the flu that divide and multiply in the warmer lungs where the immune system works better to keep them in check.
“The rhinovirus has found a niche for itself,” Iwasaki said, “and gets spread readily when we sneeze or wipe our nose” and then, say, shake someone’s hand.
That’s great for rhinoviruses but what can people do to avoid getting sick?
“I’m constantly wearing a scarf around my nose,” Iwasaki said. “It keeps my nose warmer, and I think it helps to keep the immune system operating properly.” Cyclists, skiers, and runners can wear a fleece or neoprene face mask to keep their nasal cavity near body temperature. Sipping on a warm beverage like coffee or tea while waiting outdoors for the bus or T train can also help keep nasal passages warm and moist, ideal conditions for fending off cold viruses.
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DEBORAH KOTZ