Monday, May 16, 2011

“Light” and “Low-Tar” Cigarettes

The tobacco industry gave the wrong impression about “light” and “low-tar” cigarettes to governments, health professionals and most importantly, smokers for a long time. In fact, the goal of tobacco industry by designing "light" and "low-tar" cigarettes was to convince health-concerned smokers to switch cigarette brands rather than quit. For decades, people were lead to this belief that “light cigarettes delivered less tar and nicotine and that therefore ‘lights’ were less harmful than regular cigarettes.” Today, it is clear that light cigarettes are not less harmful than regular cigarettes, and they have not decreased the risk of lung cancer among smokers. There is no evidence that light and low-tar smokers reduce their risk of cancer or heart disease. “In a cancer prevention study of nearly 1 million people in the U.S. the risk of lung cancer was no different among people who smoked medium-tar, low-tar, or very low-tar cigarettes.” Tobacco which is one of the hazardous chemicals in light cigarettes contains a complex mixture of numerous mutagens and carcinogens.
According to Peter G. Shields, who has a review on Molecular epidemiology of smoking and lung cancer in Lombardi Cancer Center of Georgetown University Medical Center, “Lung cancer is the single most common cause of death, and almost all of it is due to tobacco smoking”. What remains as an important point to realize is what chemicals are in the tobaccos that are carcinogens and how they cause lung cancer? “Specific chemicals in tobacco smoke include polycyclic aromatic hydrocarbons (PAHs), N-nitrosamines, aromatic amines, ethylene oxide, 1,3-butadiene and others. A recent critical review summarizing data for tobacco constituents proposed that tobacco-specific nitrosamines (TSNs) and PAHs are classes of compounds that most affect human cancer risk”. PAHs are normally formed from the incomplete pyrolysis of tobacco leaves; PAH-related DNA adducts have been revealed in human lung. The other groups of hazardous chemicals in Tobacco that are the most carcinogens are N-nitrosamines, and Tobacco Specific Nitrosamine (TSN). TSNs can transform human bronchial epithelial cells, and they form 3 different classes of DNA adducts: 1) Methylation of different nucleotides. 2) Oxidative DNA damage. 3) Bulky adducts, which are probably repaired by nucleotides excision repair and recombination repair. According to this study “Lower 'tar' and 'nicotine' cigarettes result in greater exposure to TSNs than high 'tar' and 'nicotine' (Brunnemann et al., 1996; Hoffmann and Hoffmann, 1997), because when people smoke harder to get more nicotine, the higher burning temperatures create more TSNs”.

Considering the harmful features of Light Cigarettes, we may want to know: “Have the tobacco companies conducted research on the amount of tar and nicotine people actually inhale while smoking light cigarettes? The tobacco industry's own documents show that companies are aware that smokers of light cigarettes compensate by taking bigger puffs.
Industry documents also show that the companies are aware of the difference between machine-measured yields of tar and nicotine and what the smoker actually inhales.”

Therefore, Light Cigarettes are not safe, and there is no such thing as a safe cigarette. The only proven way to decrease the risk of lung cancer and other tobacco-related diseases is to quit smoking completely.


Here are some more information: