Components in cigarette smoke directly damage your muscles. New research, published in The Journal of Physiology, indicates that smoking decreases the number of small blood vessels that bring oxygen and nutrients to muscles in the legs.

Smoking limits a person’s ability to exercise because it makes their muscles weaker, and it was widely believed this muscle weakness is because the lungs become inflamed and eventually destroyed by habitual smoking, thereby limiting activity and exercise. However, this study suggests that cigarette smoke directly damages muscles by reducing the number of blood vessels in leg muscles, thereby reducing the amount of oxygen and nutrients they can receive. This can impact metabolism and activity levels, both of which are risk factors for many chronic diseases, including COPD and diabetes.

The research was conducted by the University of California, San Diego, in conjunction with Universidade Federal do Rio de Janeiro and Kochi University. It involved exposing mice to smoke from tobacco cigarettes for 8 weeks, either by inhalation or by injecting them with a solution bubbled with smoke.

The study did not identify which of the approximately 4000 chemicals in cigarette smoke are responsible for this muscle damage. Further research will aim to identify the responsible chemicals and explain the process by which they reduce the number of blood vessels.

The article, “Cigarette smoke directly impairs skeletal muscle function through capillary regression and altered myofiber calcium kinetics in mice,” is available at https://physoc.onlinelibrary.wiley.com/doi/abs/10.1113/JP275888 [9] (log in required).