Don’t Smoke Cigarettes

In particular, the chemicals released by cigarette smoke — carbon monoxide, nicotine, nitrogen oxides, and cadmium — can interfere with the growth and function of immune cells, like cytokines, T cells, and B cells, according to a November 2016 review in Oncotarget.

Smoking also worsens viral and bacterial infections (especially those of the lungs, like pneumonia, flu, and tuberculosis), post-surgical infections, and rheumatoid arthritis (an autoimmune disease in which the immune system attacks the joints). If you currently smoke, there are many resources available to help you kick your habit, including counseling, nicotine replacement products, prescription non-nicotine medications, and behavioral therapy, according to the CDC.