Responding to the Reader
Are smoking-related diseases caused by the chemicals or the tobacco in cigarettes?
Story by Laura Ly/Illustration by Tanya Lam
About this feature
Alberta Innovates - Health Solutions frequently receives letters requesting information about Heritage research or about various medical conditions. "Responding to the reader" is a Research News feature intended to provide up-to-date information related to readers' questions, with the help of experts in the Alberta research community. Alberta Innovates - Health Solutions cannot provide medical advice, however; please consult your family physician about your specific health concerns.
Cigarettes cause mouth diseases; where there's smoke, there's hydrogen cyanide; and cigarettes leave you breathless: these are just a few of the warning labels on cigarette packaging. There is no doubt that cigarettes are harmful to health, but what cigarette components cause disease? Is it the cigarette chemicals or the tobacco? We asked Dr. Eric Wong, a researcher from the University of Alberta who specializes in chronic obstructive pulmonary disease (COPD) and lung cancer.
"Unless you consume very high quantities, nicotine is not really harmful—it's more addictive," notes Dr. Wong. However, as many as 4,000 chemicals are added to tobacco during the process of manufacturing cigarettes. Those 4,000 chemicals include well-known products such as arsenic, ammonia, formaldehyde, and tar. Cigarette companies add chemicals to cigarettes primarily to enhance the addictiveness of the nicotine in the tobacco. Certain chemicals speed up nicotine extraction, which in turn allows for faster nicotine consumption. But these chemicals can cause physical side effects. "Additives like menthol can cause a sore throat, so other chemicals need to be added in order to offset the irritability factor," Dr. Wong explains. "Chemicals are also used to mask some of the harsh flavouring of the nicotine."
At least 50 of the 4,000 cigarette additives are known to cause cancer. "There have been 4000 or more chemicals isolated from cigarette smoke. Some of those may be by-products of the chemical reactions from the smoking; some of them may be residuals from the preparation process," says Dr. Wong. "These additives are supposed to be safe for consumption, but we don't know what happens when the additives are burned. Chemical properties change when you burn certain materials, especially when you have multiple materials that can interact."
Dr. Wong notes that several factors impact the amount of cigarette chemicals absorbed into the body. "Depending on the type of cigarettes, how deep a drag you have, how long you smoke for, and how much you smoke a day, the amount of chemicals a smoker is exposed to can be quite different. For example, you may only smoke a few cigarettes a day, but if you take deep drags, you are exposed to a larger quantity of chemicals compared to someone who takes more shallow drags. Obviously, if you are exposed to a higher dose of chemicals, you're more likely to get cancer and disease."
Pulmonary lung rehabilitation is Dr. Wong's primary area of research. This program is designed to help patients cope with COPD after they are diagnosed. Pulmonary rehabilitation teaches patients how to use their medication correctly, control their anxiety, exercise properly, and eat healthier. It also helps patients retrain their breathing techniques. "When you smoke, you also change your breathing pattern over time. Someone who puffs on a cigarette takes very shallow breaths. Someone who drags on a cigarette tends to take deeper breaths," explains Dr. Wong. By retraining breathing techniques, pulmonary rehabilitation helps patients reduce their shortness of breath and increases their ability to exercise.
COPD is the fourth leading cause of death in Canada, yet patients typically don't recognize the symptoms as they manifest. "People who smoke when they're younger find themselves short of breath, wheezing, or coughing as they get older. They often attribute the symptoms to aging. In fact, their lungs were damaged as a result of smoking. As they get older, those lung reserves are no longer there. We are looking at ways we can raise awareness about COPD and encourage past and current smokers to go for proper testing so COPD can be diagnosed earlier and more efficiently."