Can being out in the cold make you sick? Everyone’s mother might say so. But the belief that exposure to cold temperatures can actually increase the chances of catching a cold or the flu has generally been dismissed by scientists as a myth. In fact, some contrarian medical professionals believe that standing outside in the cold is, in fact, good for you.
“Cells that fight infection in body actually increase if you go out into the cold,” says Rachel C. Vreeman, a medical doctor and co-author of the myth-busting book, Don’t Swallow Your Gum! Myths, Half-Truths, and Outright Lies About Your Body and Health.
But new research by a team of biologists and mathematicians at Britain’s University of Warwick and University of Manchester shows that there may be something to the “myth” that cold temperatures increase vulnerability to illness after all, according to a scientific paper published in the new edition of the top journal, Proceedings of the National Academy of Sciences.
The researchers found that small increases in body temperature can speed up the body’s process for preventing and responding to infections — but the scientists also discovered that when body temperature drops, the biological anti-infection process starts to slow down, according to a report on the study published by the site Science Daily.
“We have known for some time that influenza and cold epidemics tend to be worse in the winter when temperatures are cooler. Also, mice living at higher temperatures suffer less from inflammation and cancer,” said the study’s lead biologist Mike White of the University of Manchester. “These changes may now be explained by altered immune responses at different temperatures.”
The study found that when inflammation appears in the body, it signals “‘Nuclear Factor kappa B” proteins to start what the researchers called a “clock.” But the “ticking” of this clock involves the NF-kB proteins moving in and out of cells, switching genes on and off in the cell nucleus, a process that causes cells to fight tumors or infections.
While not all genes are affected by temperature changes, the study found, a certain cluster of genes that control responses to inflammation were shown to be sensitive to varying temperatures as can occur normally in the human body throughout the day. Over the course of a 24-hour period, body temperature can vary by as much as a few degrees.
“The lower body temperature during sleep might provide a fascinating explanation into how shift work, jet lag or sleep disorders cause increased inflammatory disease,” University of Warwick mathematician David Rand noted.
But if there is one thing that can be learned from the new study, it’s that your mother’s advice to bundle up when you go outside in the cold was actually pretty smart.