Effects of Smoking on Eustachian Tube and Hearing

According to the World Health Organization, smoking is the leading cause of death, responsible each year for the death of approximately 5 million people around the world due to cancer, cardiovascular disease, and respiratory disease.

Tobacco smoking seems to affect the inner ear through several mechanisms that can be categorized as direct or indirect. Toxic cigarette substances induce direct oxidative damage mediated by reactive oxygen species (ROS) and free radicals that are capable of damaging many cellular components such as DNA, protein and lipids, leading to neurosensory hearing loss that affects especially higher frequencies. Indirect damage is mediated by the vasospastic effect caused by nicotine, by the acceleration of atherosclerosis in the vascular loops of the auditory system and by the increased levels of carboxyhaemoglobin and increased blood viscosity. All these factors reduce oxygen perfusion in the organ of Corti (inner ear).

Tobacco-specific nitrosamines, a group of carcinogens produced by nicotine and tobacco-derived alkaloids, in fact, can determine squamous metaplasia of the tubal mucosa and depletion of its hair cells, delegated to the mucociliary function of the eustachian tube. The loss of mucociliary clearance mechanisms,allergic response of the mucosa to substances contained in the tobacco smoke, chemical irritation and overall immunosuppressive effects secondary to tobacco smoke exposure could lead to middle ear diseases. Smoking increases the incidence of middle ear diseases, but also because tubal dysfunction may cause in these subjects nonspecific symptoms characterised by ear fullness, subjective loss of hearing, and difficulties in middle ear equalisation.

Pezzoli M, Lofaro D, Oliva A, Orione M, Cupi D, Albera A, Bongioannini G, Albera R. Int Tinnitus J. 2017;21(2):98-103