Smokeless Tobacco: Research putting another nail in that coffin

11/01/2016

Healthy Living - November 1, 2016
William Sturrock, MD
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For years many have wondered whether using smokeless tobacco in forms such as dip, chew or E-cigs might somehow be safer because there are no combustion products that are being inhaled.  While we already do know that oral, esophageal and GI cancers are more common in those who use smokeless tobacco, users have argued that these types of cancer are not as common, and may not be as life-threatening as diseases associated with smoking such as lung cancer and COPD.  Lung cancer in particular remains the leading cause of cancer death for men and women in the US, so many with a nicotine habit have hoped to avoid this known risk of tobacco smoke to themselves, as well as the risks to others with second hand smoke.
 
Unfortunately for smokeless tobacco advocates, we now have evidence of health risks that go beyond what was previously known.  Just this past month researchers from the Harvard School of Public Health published the results of their study done in Sweden, looking at the health of men using smokeless tobacco over a 21 year time-frame. They found was that compared to men that never used these products, smokeless tobacco users suffered a 24% higher chance of prostate cancer as well as a 19% higher of death from any cause. 
 
While the involvement of the prostate may be surprising to some, scientists have known for years that smokers of tobacco products can have higher rates of disease in non-respiratory organs compared to non-smokers. Cervical cancer, skin cancer and especially bladder cancer all occur more frequently among smokers. Toxins from the tobacco combustion can be more concentrated in many different cell types as the body tries to metabolize and excrete these compounds.  However this is the first time that a study on non-combusted tobacco had evidence of disease distant from the tissues that have direct contact with the smokeless product. 
 
So, if there was no exposure to the combustion products, what is the cause of these distant effects? Consumers of smokeless products do get regular exposure to nicotine, which is absorbed through the oral mucosa and transported by the blood stream to the rest of the body.  Now researchers are more convinced that nicotine by itself can promote cancer transformation of many cell types.  Already animal studies had suggested that nicotine puts oxidative stress onto cell DNA, and with this study we have the first evidence in humans that this is the likely mechanism for these distant ill effects.
 
 Although it may ‘seem’ safer to use smokeless tobacco, Mother Nature has once more taught us that she cannot be fooled, and there is no such thing as a less dangerous consumption of this product. Unfortunately, children growing up in the US get mixed messages about smokeless tobacco when they see their role-models in many sports (especially baseball) using these products.   It turns out that there has been a public health campaign to get baseball to kick the habit that has been gaining momentum. Smokeless tobacco usage is now prohibited in the minor leagues, but only Boston, Chicago and the California teams have outlawed its use in the majors.  Now, if we can just get the rest of the league to step up to the plate and ban smokeless tobacco in all of its forms from our national pastime, then that would be a real reason to cheer!