Why Quitting Smoking Can Prolong Your Life

I frequently hear questions like, “Why should I quit smoking, the damage is already done?” or “I quit smoking, but I don’t feel any different?” At times like this I like to show my patients the Fletcher-Peto Curve, a visual that shows how quitting smoking can prolong your life. The chart can be seen at this link.

Lung function decreases over time

The curve was created in 1977 by Charles Fletcher and Richard Peto. It was based on an eight year study of Englishmen published in 1976. It measured their forced expiratory volume in one second (FEV1), which is perhaps one of the better means for measuring lung function as it cannot be faked.

The curve shows that lung function gradually declines over time even for those who never smoked. If you look at the graphic, this is represented by the green line. This pretty much shows that, as we age, we have some degree of naturally occurring loss of lung tissue, and gradual loss of lung function, over time. Symptoms usually don’t present, if they present at all, until the advanced years of life. This is usually diagnosed as senile emphysema.

The curve also shows that lung function decline is accelerated in people who chronically smoke cigarettes. If you look at the graphic, this is represented by the red line. This pretty much shows that chronic smoking destroys lung function at an average speed about twice that for those who never smoked.

Quitting always helps

However, there is good news here, and this is what we are looking for. The curve shows that quitting smoking, no matter when you quit, slows the progression of the disease and prolongs life. The blue line represents a person who quit smoking at the age of 45, and the yellow line a person who quit at the age of 65. As you can see, their predicted lifespans are longer than the person who never quit smoking.

The most impressive takeaway from this is that it is NEVER TOO LATE TO QUIT!!!

Improve the quality and length of your life

Think of it this way: If you are diagnosed with COPD, nearly every expert on the subject, be it a nurse, respiratory therapist, or physician, is going to talk to you about the importance of quitting smoking. We do not do this to torture you. There is both scientific and clinical evidence to support the claims that quitting smoking, and smoking abstinence, can both improve the quality of and prolong your life.

It is based on the Fletcher-Peto curve that nearly all COPD guidelines recommend quitting smoking as the first step to controlling COPD. This is not a coincidence.

It is based on this curve that COPD diagnosis and staging of severity are defined by most COPD guidelines, including the Global Initiative for Chronic Obstructive Lung Disease (GOLD) COPD guidelines, and the American Thoracic Society (ATS) COPD Guidelines.

Never quit quitting

Fellow COPD expert Kathi MacNaughton wrote about the benefits of quitting smoking in her excellent post, “The Rewards of Quitting Smoking in a Nutshell.” The idea that quitting smoking can also prolong your life is yet another benefit to add to the list.

Yes, there are limitations to this curve. It is based on only a small sample of COPD patients for only a short period of time. So, yes, there are some who criticize it.

Still, despite its limitations, it’s a simple visual showing the natural progression of COPD over time, and the benefits of quitting smoking. It is well respected among the medical community, and it’s used as an integral part of smoking cessation kits. It shows you, right now, where you are at.

So, while the damage to your lungs cannot be undone, quitting smoking can still improve the quality, and prolong the length, of your life. So you should never quit quitting. If you already succeeded at quitting smoking, rest assured that you did the right thing.