Smoking menthol cigarettes may make butting out for good harder: study

TORONTO (CP) - Menthol and regular cigarettes appear to be equally harmful to the cardiovascular system and lungs, but smokers of menthols may have a harder time butting out for good, new research suggests.

In a study that followed more than 1,500 smokers over 15 years, U.S. researchers found that those who smoked menthol cigarettes in 1985 were more likely to still be smoking in 2000: almost 70 per cent of those whose tobacco of choice was menthol were still smoking compared with about 55 per cent of those who chose regular cigarettes.

"The main finding is that per cigarette smoked, menthol cigarettes are no more harmful than non-menthol in terms of arteriosclerosis or pulmonary (lung) damage," said lead investigator Dr. Mark Pletcher, a clinician and epidemiologist at the University of California in San Francisco.

"Certainly they're both harmful. It doesn't matter really what you smoke - you shouldn't," Pletcher said Monday from San Francisco. "But menthol smokers may have a harder time quitting and may need some extra support when they try to quit."

The authors found that smoking menthols was associated with "a lower likelihood of trying to quit in the first place." As well, menthol smokers were almost twice as likely to relapse after quitting and less likely to stop for a sustained period of time.

Pletcher said there may be biological reasons for that: Because menthol (a compound found in peppermint oil) creates smoke that feels cool and anesthesizes nerve endings in the throat and air passages, smokers may inhale deeper and be able to tolerate more cigarettes.

"Menthol can increase breath-holding, the way people inhale and hold their breath while they're smoking," he said, adding that menthol cigarettes may also be more addictive.

"There is a biological basis in that menthol appears to inhibit the metabolism of nicotine. If you inhibit nicotine metabolism, it will stay around longer. So you get more of a hit of the addictive substance of smoking."

Dr. Peter Selby, head of the nicotine dependence clinic at the Centre for Addiction and Mental Health in Toronto, said the study refutes the notion some smokers hold that menthol products are not as harmful as regular cigarettes.

"It's got this quasi-clean image attached to it," Selby said of minty menthol. "It's put in your cough drops and cough medicine . . . and it's in our toothpaste. So you discount how dangerous something potentially is."

"So it's not only the addictive nature from a biochemical perspective, but also psychologically how it plays in people's minds," he said. "Menthol cigarettes are not safer. And it may make it even harder to quit if you think smoking menthol cigarettes is cleaner or healthier or safer."

In the United States, about 25 per cent of smokers choose menthol; industry-wide figures aren't available for Canada, but menthol makes up only two per cent of cigarette products sold by the country's largest producer, Imperial Tobacco, company spokeswoman Catherine Doyle said from Montreal.

The researchers measured associations between the type of cigarette smoked and cessation of tobacco use, along with the level of coronary calcification (a buildup of calcium in the coronary arteries) in subjects and their change in lung function over a 10-year period.

Both coronary calcification and a decline in lung function were linked to the number of cigarettes smoked, but the type of cigarette appeared to make no difference, the study found.

The researchers, whose paper was published Monday in the Archives of Internal Medicine, enrolled 808 women and 727 men, aged 18 to 30, as part of the Coronary Artery Risk Development in Young Adults (CARDIA) study. At the beginning of the study, 972 (63 per cent) of the participants preferred menthol cigarettes, while 563 (36 per cent) smoked non-menthols.

Pletcher said menthol cigarettes are much more popular among African Americans than those of European descent. Almost 90 per cent of African Americans in the study puffed on menthols, compared with just 30 per cent of European Americans, he said.

When it came to the amount of tobacco indulgence, African Americans tended to smoke less than European Americans - yet they had disproportionately high rates of cancer, cardiovascular disease and other smoking-related illnesses, the researchers said.

"For a variety of historical and cultural reasons, including targeted advertising by the tobacco industry, African American smokers are much more likely to smoke menthol cigarettes than European American smokers," the authors wrote.

Pletcher said the researchers wanted to determine if menthol in cigarettes was behind higher rates of smoking-related disease among African-Americans. If that were the case, he said, then "getting rid of menthol would be a way to eliminate a lot of health problems."

But once the researchers factored in other social and demographic variables, most of this difference was explained by the fact that African Americans were both more likely to smoke menthols and less likely to quit smoking.

"Mentholation of cigarettes does not seem to explain disparities in ischemic heart disease and obstructive pulmonary disease between African Americans and European Americans in the United States, but may partially explain lower rates of smoking cessation among African American smokers," the authors conclude.