Scientists now believe they know why people get more colds and the flu during the winter months.
Researchers found that the cold air itself damages people's immune response occurring in the nose, which causes more respiratory illnesses, according to a recent study published in The Journal of Allergy and Clinical Immunology that is being called a scientific breakthrough.
“This is the first time that we have a biologic, molecular explanation regarding one factor of our innate immune response that appears to be limited by colder temperatures,” said rhinologist Dr. Zara Patel, a professor of otolaryngology and head and neck surgery at Stanford University School of Medicine in California, who was not involved in the study, according to CNN.
The study states that reducing temperature inside the nose by as little as 9 degrees Fahrenheit is capable of nearly half of the billions of virus and bacteria-fighting cells located in the human nostrils.
“Cold air is associated with increased viral infection because you’ve essentially lost half of your immunity just by that small drop in temperature,” said rhinologist Dr. Benjamin Bleier, director of otolaryngology at Massachusetts Eye and Ear and an associate professor at Harvard Medical School in Boston.
“it’s important to remember that these are in vitro studies, meaning that although it is using human tissue in the lab to study this immune response, it is not a study being carried out inside someone’s actual nose,” Patel added in an email to CNN. “Often the findings of in vitro studies are confirmed in vivo, but not always.”
Flu activity often increases in October and reaches its peak between December and February, according to the U.S. Centers for Disease Control and Prevention.