British scientists have revealed that protective genes account for the presence of smokers with healthy lungs, in spite of heavy tobacco use.
Experts at the Medical Research Council in the United Kingdom presented their findings at the annual European Respiratory Society meeting in Amsterdam. Later, their scientific paper was published in the journal Lancet Respiratory Medicine.
The study was conducted by analyzing health lung data belonging to 50,000 subjects, aged between 40 and 69, including smokers and non-smokers. This information was collected from UK’s biobank project, in an effort to understand the genetic and environmental factors contributing to COPD (chronic obstructive pulmonary disease).
The lung condition causes inflammation and thickening of the respiratory tract, coughing, wheezing, recurrent infections and progressive breathlessness. Normally, smoking is considered to be the most significant cause of this disease, but researchers wanted to see if other influences may play a role also.
Scientists assessed non-smokers against non-smokers, as well as those with COPD against those without the condition, and encountered some interesting DNA sections that may be linked to the disease.
Basically, it was discovered that some subjects had a lower probability of developing COPD, simply because of their genes, no matter how much they may have smoked.
DNA mutations linked to chromosome 17 boost lung function and cause smokers to recover faster despite tobacco use, while some non-smokers may actually be predisposed to the disease.
Nevertheless, scientists still insist that smoking is highly inadvisable, especially since most patients may not know if they have these protective genes.
“The strongest thing that people can do to affect their future health in terms of COPD and also smoking-related disease like cancer and heart disease is to stop smoking”, declared Professor Martin Tobin, researcher at the University of Leicester.
Scientists also identified genetic code that is more frequently encountered among smokers than non-smokers. Although for now these are just speculations, it may be that DNA sections affect how easily addicted a person is to nicotine, and the likeliness of becoming a long-term smoker.
It has been proven that long-term tobacco use is the most widespread cause of lung cancer, accounting for 80-90% of the cases. Now these findings may help shed light as to why some people remain healthy despite a lifetime of nicotine consumption, while others who have never smoked may develop lung tumors anyway.
According to researchers, this new insight into the complexities of lung health may assist them in developing ground-breaking treatments that improve lung function. It may help identify patients with genetic predisposition to tobacco addiction, and also allow otherwise healthy people to know if their lungs are capable of healing properly.
Nowadays, more than 24 million Americans are affected by COPD, according to the Behavior Risk Surveillance Survey conducted by the Centers for Disease Control and Prevention. Over half of these patients are undiagnosed, despite having the symptoms. Early screening is essential for identifying the disease, and usually consists in taking a spirometry test.
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