Why Do Most Smokers Not Get COPD?

Smoking is often cited as the most common cause of COPD. This makes sense, considering studies show 75% of COPDers are current or former smokers.¹ Still, it’s interesting to note that only 20% of smokers develop COPD.² Likewise, studies show that 25% of COPDers never smoked. So, why is it that only some smokers develop COPD? Why is it that some non-smokers do develop COPD? Let’s investigate.

The role of genes

One theory I discussed in my post “Is All COPD Genetic?” is that there are certain genes that can become changed over time. This means that a gene is mutated (changed) by something in the environment. This something may chemicals from cigarette or wood smoke. It may be chemicals in the air at your work.

Mutated genes release proteins that tell cells to do something abnormal. In our case, this is what causes loss of lung function and COPD. So, having COPD genes makes you susceptible to developing COPD. That is if this theory holds up.³

You can read more on this theory by clicking the linked article above. Genetic research is still a relatively new area of science. Researchers are working to learn more about potential COPD genes and for treatments to block them from causing COPD.

Near birth events

Something happens near birth that increases your risk of developing COPD later in life. I discussed some of these things in my post, “Near Birth Events May Cause COPD.” In that post, I discussed various events that may occur before or shortly after birth that may stunt lung growth and development. This may cause airways to be smaller in proportion to lung size.

The results of a recent study show that this may be a viable theory. The keywords to note are “Small airways relative to the size of their lungs.” The study showed that those who fall into this category experienced a lower breathing capacity and lower lung function, compared to those with airways of normal size.⁴

Researchers concluded that those with smaller airways have an increased risk of developing COPD. This remains true even if they did not smoke or were exposed to other risk factors for COPD. If this theory holds up, researchers need to learn why it happens and develop strategies to prevent it from happening.⁴

The study was thorough, with researchers looking at over 6,500 subjects. These subjects participated in three different studies that had already been concluded. Some were smokers and some did not smoke. The studies included people of various nationalities.

More research to come

Theories are nice in that they give researchers something to focus on. Listed here are two of the more common ones to explain COPD. However, there may be others out there that researchers are looking into too. You can be assured that many more studies in these areas will be forthcoming. As researchers learn more, the hope is that their findings will prevent people from getting COPD in the future. Or it may lead to better treatment options for those currently living with it. As we learn more, we will certainly keep you posted.