Can smoking have a positive effect on the course of certain diseases? A systematic review

Background: Smoking cigarettes is a process during which many harmful substances are introduced into the lungs and the influence of these substances on the human body is not completely known. There are many diseases caused by smoking. Interestingly, there are also reports of positive consequences of smoking on some disorders. Aim of the study: The purpose of this article is to review the literature in regards to the diseases in which cigarettes might have a paradoxically beneficial effect — both on the onset and their course. We also want to focus on the mechanisms responsible for this impact. Material and Methods: Electronic searching of PubMed was performed. We analyzed articles published in the last 10 years with a particular emphasis on the most recent publications. Combinations of the following words were used: “smoking”, “nicotine”, and “autoimmune”. Publications were selected for reliability and non-bias. Results: A total of 69 articles out of 2979 qualified for the review. Only studies involving humans were included. The positive effect of smoking cigarettes is observed especially in immunological diseases. It is possible that it is mediated by both stimulating and suppressing the immune system. It is assumed that cigarettes can reduce the risk of developing certain diseases. Smoking might also have an impact on the course of different comorbidities in the same patient. Conclusions: There are many different mechanisms through which cigarette smoke and nicotine affect the human body. The harmful impact of these substances on one’s health has been demonstrated and their addictive component disqualifies them as remedies. Analysis of the mechanisms responsible for the beneficial effects of nicotine can lead to the search for new forms of therapy and prevention.