By Randy Dotinga
MONDAY, May 22, 2017 (HealthDay News) -- Filtered cigarettes might be even more lethal than unfiltered ones, and a new review suggests that they have been boosting rates of a cancer that takes root deep in the lungs.
The findings have prompted the review authors to call for federal regulators to ban the use of ventilation holes in cigarette filters.
"Modern cigarettes are more risky when it comes to lung cancer," said review co-author Dr. Peter Shields. He is deputy director with the Comprehensive Cancer Center at Ohio State University.
"The design of cigarette filters that have ventilation can make the cigarettes even more dangerous because those holes can change how the tobacco burns, allowing smokers to inhale more smoke and think that the smoke is safer because it is smoother," Shields explained.
The tobacco industry has embraced filters for over 50 years, often touting them as "light" cigarettes that reduce tar intake. Tiny ventilation holes in these filters allow smokers to take in more fresh air.
For the new report, researchers reviewed almost 3,300 tobacco studies and internal tobacco company research. The investigators determined that their analysis "strongly suggests" that these filters have contributed to the rise in a form of lung cancer known as adenocarcinoma.
"The design of cigarette filters that have ventilation can make the cigarettes even more dangerous," Shields said. "This applies to all cigarettes, because almost all the cigarettes on the market have the holes, not just the ones that used to be called 'lights' and 'ultra-lights.'"
Shields said research shows that smokers take deeper drags when cigarettes are ventilated. As a result, "smoke can go deeper into the lungs where adenocarcinomas more commonly develop," he said.
Adenocarcinomas are a kind of non-small cell lung cancer that penetrates deeply into the lungs. While the prevalence of lung cancer has gone down, the number of adenocarcinomas has gone up, and a 2014 U.S. Surgeon General's report blames the increase on "changes in the design and composition of cigarettes since the 1950s."
The new report recommends that the U.S. Food and Drug Administration should consider a ban on ventilating filters, although Shields cautioned that "we are not saying to remove filters." Instead, the report authors want "only to change their designs by removing the holes on the filters."
Dr. Norman Edelman, a senior scientific advisor with the American Lung Association, praised the new report, although he noted that his association has not taken a stand on the future of cigarette filters.
"There's always the problem of unintended consequences," he said. "What happens if we take the filters off? People might believe that 'Well, they took the offending agents off cigarettes, so they're safe now.' The whole point of unintended consequences is they're consequences you don't think about."
Still, Edelman said, "we strongly supported the legislation that gave the FDA control over tobacco products. Their goal should always be to reduce harm to the greatest extent possible."
Altria, a major tobacco manufacturer that is the parent company of Philip Morris, didn't reply to a request for comment.
The study was published online May 22 in the Journal of the National Cancer Institute.