Smoking Menthol Cigarettes Tied to Stroke
With additional adjustments for reported histories of multiple cardiopulmonary conditions, menthol cigarette smoking was still significantly associated specifically with stroke and at odds ratios very similar to those in Vozoris’s primary analysis.
In NHANES during the period covered by the analysis, participants were asked about their smoking habits, including their preference for menthol versus nonmenthol cigarettes, at what age they started smoking, how often they had smoked in the preceding month, and how many cigarettes they smoked on average.
In the latest look at the hazards of menthols vs. regular cigarettes, Canadian researchers found the stroke risk for those who smoked menthols was more than twice that for regular-cigarette smokers. And for women and non-blacks, the risk was more than three times higher.
But no elevated risk was seen between mentholated cigarette smoking and high blood pressure, heart attack, heart failure and the lung disease chronic obstructive pulmonary disease (COPD), the researchers said.
Exactly how, or if, smoking menthol cigarettes raises risk of stroke more than other cigarettes types is not fully understood.
“One potential mechanism is that menthol stimulates upper-airway cold receptors, which can increase breath-holding time, which may in turn facilitate the entrance of cigarette particulate matter into the lungs,” said study author Dr. Nicholas Vozoris of St. Michael’s Hospital, in Toronto. “Why smoking mentholated cigarettes would not result in an increase in forms of cardiopulmonary disease, other than stroke, is not clear.”
The findings appear in a research letter published April 9 in the Archives of Internal Medicine.
Health history information was also supplied by respondents, who were read a list of conditions and asked whether they had been told they had them by a health professional.
Vozoris noted the oddity that menthol cigarettes were apparently associated with stroke but not other cardiovascular problems.
“A possible explanation is that mentholated cigarettes exert some selective effects on the cerebrovascular system,” he wrote, citing previous studies indicating that menthol cigarette smokers had increased carotid artery stiffness whereas menthol and nonmenthol cigarette smoking had the same effects on coronary artery reserve flow.
However, he also conceded that the association of menthol cigarettes and stroke could have non-causal explanations, such as that smokers choosing menthol cigarettes may have higher baseline risk for stroke or decreased likelihood of having medical therapy to prevent stroke.
Shortly after the FDA’s authority to regulate tobacco was expanded in 2009, the agency banned most flavorings in cigarettes but exempted menthol while it studied whether it poses special risks.
Last March, an FDA advisory panel determined that mentholation does indeed make cigarettes more harmful, largely by making them more addictive and therefore harder for smokers to quit.
On the other hand, it also found that there wasn’t enough evidence to say whether menthol cigarette smokers were at higher risk of disease than other smokers.
The FDA has not yet taken any action against menthol in cigarettes.
No external funding for the analysis was reported.
Vozoris declared he had no relevant financial interests.
Primary source: Archives of Internal Medicine
Source reference: Vozoris N “Mentholated cigarettes and cardiovascular and pulmonary diseases: A population-based study” Arch Intern Med 2012; 172: 590-91.