Smokers may perceive “light” cigarettes as a less dangerous option, but a new study found that they could be even more harmful than traditional smokes.

Though lung cancer rates have declined, the rates of adenocarcinoma — now the most common type of lung cancer — have risen dramatically over the past few decades.

Light cigarettes are likely to blame, according to the study.

Scientists at The Ohio State University Comprehensive Cancer Center - Arthur G. James Cancer Hospital and Richard J. Solove Research Institute (OSUCCC - James), and five other institutions, wanted to know why the rate of adenocarcinoma was increasing.

Dr. Peter Shields, a medical oncologist OSUCCC – James, who specializes in lung cancer, and study author, said the research shows the relationship between the additional holes in light cigarettes and the increased rates of adenocarcinoma.

His team examined existing studies including clinical trials performed on humans. They found that the holes let smokers inhale more carcinogens, toxins, and mutagens compared with regular cigarettes.

“What is especially concerning is that these holes are still added to virtually all cigarettes that are smoked today,” said Shields.

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Ventilation and cancer rates

About 50 years ago, more holes were added to filters to make light, or high-ventilation, cigarettes.

The change was a strategy to market the products as healthier, but it fooled smokers and the public into thinking the cigarettes were safer.

Filtered cigarettes without ventilation holes were commonly sold in the United States in the 1950s and 1960s, explained Eric Jacobs, PhD, strategic director of pharmacoepidemiology with the American Cancer Society.

He said they were added to some brands during the 1960s, and have dominated the market since the 1970s.

“The filter ventilation holes change how the tobacco is burned, producing more carcinogens, which then allows the smoke to reach the deeper parts of the lung where adenocarcinomas more frequently occur,” Shields said.

Dr. Norman H. Edelman, the senior scientific advisor with the American Lung Association, explained that scientists have known that the change in the cell type of lung cancer changed around the time that filtered cigarettes went on the market.

About one-third of lung cancer cases used to be adenocarcinomas. Now about 80 to 85 percent are adenocarcinomas.

“There’s a correlation,” Edelman told Healthline.

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Safer filters?

That said, Shields believes that the solution is not to remove the filters completely.

He said there is a lack of research on the impact of filtered cigarettes before they had holes.

He recommends studying the impacts of taking out the holes, as there could be some unintended consequences such as the cigarettes being more toxic. Researchers should also examine making the size and amount of holes universal among all cigarette types, as they vary greatly now.

Dr. Michael Steinberg, a professor at the Rutgers Robert Wood Johnson Medical School, and director of the Rutgers Tobacco Dependence Program, said the important point for smokers is that “the belief filtered cigarettes are ‘safer’ or ‘not as harmful’ does not appear to be the case at all.”

What’s clear from the team’s work is that cases of adenocarcinoma have gone up. He thinks that is because of two changes in cigarettes over the past few decades: the addition of holes, and an increase in cancerous tobacco.

While it’s hard to tell if filters and ventilation increase cancer, they have been ineffective at reducing health dangers, Edelman noted.

Experts can’t say if removing filters completely could dissuade smokers, as the taste of cigarettes is drastically stronger without a filter.

Edelman is not sure if it would deter smokers altogether, or turn them on to e-cigarettes.

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A shift on cigarettes?

Shields’ research team is calling on the U.S. Food and Drug Administration (FDA), which regulates tobacco products, to better regulate ventilation holes or ban them altogether.

Currently, tobacco companies cannot label or market the cigarettes as having “low tar” or being “light.”

“The FDA has a public health obligation to take immediate regulatory action to eliminate the use of ventilation holes on cigarettes,” said Shields. “It is a somewhat complicated process to enact such regulations, but there is more than enough data to start the process. We believe that such an action would drive down the use and toxicity of conventional cigarettes, and drive smokers to either quit or use less harmful products.”

He said that the FDA can regulate one or both issues. His team has presented the study to the FDA, but he said he is not sure how they will proceed.

The FDA could conduct more research or use the study to further regulate and change the way cigarettes are currently designed.

“Whatever we can do to make cigarettes safer is the goal,” Shields told Healthline.

He doesn’t advocate that smokers switch to a lower ventilated cigarette.

“They really just need to stop,” he added.

Edelman agrees the FDA has to step up in the matter, and this study could pave the way for that.

“We fully support the role of the FDA in reducing the harm of tobacco products to the absolute minimum that it’s possible to do,” Edelman said.

Aside from the FDA taking action, current research is assessing how to make nicotine levels lower so it is no longer addictive.

“We’re going to drive smokers to a much safer product,” Shields said.