𝐖𝐡𝐲 𝐂𝐢𝐠𝐚𝐫𝐞𝐭𝐭𝐞 𝐒𝐦𝐨𝐤𝐞 𝐌𝐚𝐤𝐞𝐬 𝐅𝐥𝐮 𝐚𝐧𝐝 𝐎𝐭𝐡𝐞𝐫 𝐕𝐢𝐫𝐚𝐥 𝐈𝐧𝐟𝐞𝐜𝐭𝐢𝐨𝐧𝐬 𝐖𝐨𝐫𝐬𝐞

Why are cold and flu virus symptoms that are regularly mild and temporary in non-smokers shocking the system of a smoker? Published in the  Journal of Clinician Investigation,  the study discovered how viruses and cigarette smoke act together to enhance lung irritation and damage. 

It has not been clear why smokers experience a more amplified reaction to viral infections. Smokers have more likely than non-smokers to die during previous influenza epidemics and are more susceptible to chronic obstructive pulmonary disease (COPD). 

Additionally, children exposed to second-hand smoke react more severely when infected with a respiratory virus. The general view has been that cigarette smoke diminishes anti-viral responses. 

The Yale researchers realized the opposite was true. Their experiments demonstrated that the immune systems of mice subjected to cigarette smoke from only two cigarettes per day for two weeks overreacted when exposed to a simulation of the flu virus. The mice’s immune systems cleared the virus usually, but the amplified irritation produced heightened levels of tissue damage.

The anti-viral responses in the cigarette smoke-exposed mice were not only not defective but were hyperactive. These findings suggest that smokers do not get in trouble because they can’t clear or fight off the virus; they get in trouble because they overreact to it. Smokers are using the equivalent of a sledgehammer, rather than a fly swatter, to get rid of a fly.

The team found that mice with viral infections exposed to cigarette smoke had accelerated emphysema and airway scarring.  These studies have explained how cigarette smoke exposure and viral infections interact to worsen breathing problems in diseases like COPD.