Smoking low-tar cigarettes does not mean less risk

Switching to low-tar cigarettes does not necessarily lower the risk of lung cancer, according to a new study, the results of which were published in the January 10 issue of the British Medical Journal..

Tar is the term given to the toxic chemicals found in cigarettes. High-tar cigarettes contain at least 22 milligrams (mg) of tar, medium-tar cigarettes from 15 mg to 21 mg, and low-tar cigarettes 7 mg or less of tar.

In a six-year study involving 364,239 men and 576,535 women in the United States, researchers found the individuals who smoked low-tar cigarettes carried very much the same risk of dying from lung cancer as individuals who smoked medium-tar cigarettes. Most likely to die of lung cancer were people who smoked high-tar, unfiltered cigarettes.

The study also found that despite the higher chances of high-tar cigarette smokers dying of lung cancer, the odds of dying from lung cancer are not affected significantly by the type of cigarette smoked even when factors such as medical history, diet and occupation are considered.

The study showed that all smokers run a greater risk of acquiring lung cancer than individuals who have never smoked or those who had stopped smoking before reaching 35 years of age.

According to the researchers, led by Dr. Jeffrey Harris of Massachusetts General Hospital in Boston, USA, the results of the study suggest that quitting is the only way to reduce the risk of acquiring lung cancer.

Nonetheless, researchers acknowledged the benefits that could be gained by reducing the use of high-tar, unfiltered cigarettes, which account for just about 1 percent of cigarette sales in the US and the UK, but roughly 6% to 20% of cigarette sales in Eastern Europe, 15% in France, and 20% in China.

Most previous studies had compared the risk of smoking high-tar cigarettes smokers with that of smoking medium-tar cigarettes. Very little research has been done to look into the relationship between low- and very low-tar cigarette smoking and lung cancer.