Can cold weather can lower your immune system?

[Luke_Wilbur]

Our family debate whether going out in the cold weather when you are sick could actually make you worse off.

 

Interestingly enough a new theory that has been put forward to explain the seasonality of colds and flu, and this theory puts forward the idea that our noses are colder in winter than summer and that cooling of the nose lowers resistance to infection. If the weather is freezing outside we wrap up in winter clothes but we still leave our nose exposed to the freezing air. Every time we breathe in we cool the nasal lining and weaken our local defences against infection. If this theory is correct then covering our nose with a scarf in cold weather could help prevent colds.

 

Eccles R. An explanation for the seasonality of acute upper respiratory tract viral infections. Acta Otolaryngologica (Stockholm) 2002; 122:183-191.

 

Exposure to cold has often been associated with increased incidence and severity of respiratory tract infections. The data available suggest that exposure to cold, either through exposure to low environmental temperatures or during induced hypothermia, increases the risk of developing upper and lower respiratory tract infections and dying from them; in addition, the longer the duration of exposure the higher the risk of infection. Although not all studies agree, most of the available evidence from laboratory and clinical studies suggests that inhaled cold air, cooling of the body surface and cold stress induced by lowering the core body temperature cause pathophysiological responses such as vasoconstriction in the respiratory tract mucosa and suppression of immune responses, which are responsible for increased susceptibility to infections. The general public and public health authorities should therefore keep this in mind and take appropriate measures to prevent increases in morbidity and mortality during winter due to respiratory infections.

 

http://www.ncbi.nlm.nih.gov/pubmed/17705968