Study Finds: Smoking Reduces Human Immunity

Russian media reports that biologists published a study in the Journal of Endodontics concluding that smoking not only increases the risk of lung cancer, asthma, and chronic obstructive pulmonary disease but also significantly reduces human immunity.
 
According to a report by RIA Novosti on September 26, Anita Aminosharia from Case Western Reserve University in the United States stated: “This can explain why many smokers have cavities and other oral diseases, and why their gums heal more slowly than non-smokers. TNF-α and hBD-2 proteins serve as the last line of defense. Smoking causes them to be 'killed' before they even join the fight.”

According to the World Health Organization, there are approximately 1.1 billion smokers worldwide, most of whom live in developing and transitional countries. Recent research by British medical scientists indicates that about 60% of smokers die prematurely due to their tobacco addiction rather than other causes.

Reports indicate that in recent years, scientists have begun to notice that smoking significantly accelerates aging and hearing loss. This has compelled scientists to study in detail the various side effects associated with both passive and active smoking.

Aminosharia and colleagues discovered an unexpected adverse effect while studying how cigarette smoke affects dental pulp and other dental tissues. For this, scientists recruited 70 volunteers with untreated cavities and invited them to receive treatment at the Case Western Reserve University clinic.

Reports state that half of the volunteers were smokers, while the others had never smoked. When dentists removed nerves, biologists collected samples of healthy and damaged dental pulp and analyzed the hormones and proteins contained in the dental tissues.

Aminosharia explained: “Initially, we expected to see differences in the levels of specific signaling substances related to immunity, with smokers having lower levels than the others. To our surprise, these 'defensive' molecules were not just reduced; they were completely absent in the dental pulp.”

Reports indicate that, for example, there were almost no TNF-α protein molecules in the dental tissues of smokers—this is one of the most important substances that stimulates immune cell activity, responsible for releasing inflammation and putting the immune system into 'emergency mode.' Similarly, the other two signaling molecules in smokers' teeth that are responsible for resisting microorganisms, β-defensin 2 and β-defensin 3, were also very low.

Scientists point out that this distinction can explain why smokers are twice as likely to suffer from severe pulpitis requiring nerve removal and various gum diseases. Aminosharia and colleagues believe that the immune system activity in other tissues and organs also declines in a similar manner.