Is cigarette smoking a risk factor for COVID-19?
COVID-19 is a newly identified disease (Li et al., 2020) and only a few studies have been made regarding it’s relation to smoking (Scientific American, 2020).
However, a study of 1.099 COVID-19 patients, reported that 12.4% of smokers died, required intensive care unit admission or mechanical ventilation compared with 4.7% among non-smokers (BMJ, 2020 citied Guan, et al, 2020).
As a matter of fact, a healthy immune system is significant in the treatment and possibly the prevention of COVID-19 (Petric, 2020). Smoking weakens the immune system, making it less efficient against infections(Quit.org.au). Moreover, Smoking:
May transfer viruses inside the body via the mouth
COVID-19 may survive for several hours to days on surfaces (NIH, 2020). When a smoker puts a cigarette in their mouth, they may transfer viruses from their fingers to the oral mucus membranes (CDC, 2020), (Quit.org.au, n.d.)
Reduces vitamin and mineral levels, related to immunity, such as:
- Selenium (Kocyigit, Erel & Gur, 2002), (Hemat, 2004)
- Vitamin C (Chow et al., 2013), (Carr & Lykkesfeldt, 2018)
- Magnesium (Unkiewicz-Winiarczyk, 2009), (Gonza & Marcos, 2003)
- Vitamin D (Kassi et al, 2015), (Litwack, 2011)
- Vitamin E (Bendich,1990), (Petrich, 2020)
- Vitamin A (Bendich,1990), (Petrich, 2020)
Harms and weakens the lungs
- Decreases lung capacity (Pack & Rochard, 2016)
- Contributes to lung inflammation (Deepak et al., 2009)
- Prevents lungs from self-cleaning
- Makes lungs unable to kill microbes and prevent infections
Cilia are tiny hair-like projections that line the airways. With the help of the mucus, cilia cleans the lungs from inhaled particles and pathogens (Dezube, 2019). Smoking temporarily paralyzes Cillia (Ozdogan, 2020). To make things worse, smokers have increased and thicker mucus that clogs the lungs and makes them prone to infections and difficult to clean (Quit.org.au, n.d.)
Alveolar macrophages are the components that comprise the part of the lungs called Alveoli, they are releasing antimicrobials such as lysozymes, antimicrobial peptides, proteases cytokines and chemokines (Hussell, n.d.). They are essential for preventing microbial infections and clearing bacteria (Monick et al., 2010).
Smoking reduces enormously the number of Natural killer cells
Natural killer cells are named as such, due to their role in killing virally infected cells. Smoking reduces enormously the number of natural killer cells (Tolerud et al., 1989).
In a recent study, Natural killer cell numbers were significantly decreased in patients with COVID-19 (Qin et al., 2020).
Smoking is a risk factor for COVID-19, moreover, it harms nearly every organ of the human body (CDC) Increases the risk of developing more than 50 serious health conditions (NHS, n.d.) and decreases the lifespan for an average of 10 years compared to nonsmokers (CDC, n.d.). Therefore smoking cessation should be a priority for smokers regardless of its relation to the COVID-19 pandemic.
A light outdoor exercise may help in easing the side effects of smoking cessation. Moreover, exercise boosts the immune system, improves its defensive abilities, it has anti-inflammatory properties and the sunlight may boost vitamin D, melatonin and serotonin levels (Mead, 2008).
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