"Light" or filtered cigarettes are typically seen as a healthier choice for smokers.
Yet a new review featured in the Journal of the National Cancer Institute revealed them to actually be more dangerous than the traditional, unfiltered version, particularly because of the ventilation holes in the filters.
Contrary to popular belief, filtered cigarettes don't offer smokers any health benefits, attests the study, which examined more than 3,284 published scientific literature on tobacco, as well as internal research documents provided by tobacco companies.
What is more, the research shows there is a causal relationship between cigarette filters and a specific form of lung cancer called adenocarcinoma, which typically arises in the periphery or farther reaches of the lung and is difficult to treat.
Cigarette Filters Linked To Higher Adenocarcinoma Rates
The research, conducted by the Comprehensive Cancer Center at Ohio State University, investigated why the number of adenocarcinoma cases has increased in the United States, in spite of the continuous decline in overall lung cancer rates.
"Adenocarcinoma, which is today the most common type of lung cancer, is continuing to increase," said Dr. Peter Shields, the center's deputy director and senior study author, in a news release.
"There is mounting evidence that tiny holes found near the filter of certain cigarettes are largely to blame," he added.
These ventilation holes were introduced in the mid-1960s with the purpose of making cigarettes taste smoother and putting a safer spin on smoking.
Tobacco companies adopted filter ventilation in the idea that ventilation holes allegedly reduce the tar intake, thus allowing smokers to breathe in more fresh air and making the inhaled smoke less harmful.
Yet the researchers note an increase in adenocarcinoma rates in the past 50 years.
"Filter ventilation was adopted in the mid-1960s and was initially equated with making a cigarette safer. Since then, lung adenocarcinoma rates paradoxically increased relative to other lung cancer subtypes," write the authors in their paper, published May 22.
Why Cigarette Filters Are Harmful
The ventilation holes in cigarette filters allow the cigarette to burn slower and at a lower temperature.
This leads to more smoldering and more incomplete combustions. As a direct result of the slowed combustion, higher amount of toxic chemicals are produced.
Filtered cigarettes can also make smokers take in more puffs. Since users inhale more smoke, which is diluted with air, more toxic chemicals are forced deeper into the lungs.
"The filter ventilation holes change how the tobacco is burned, producing more carcinogens, which then also allows the smoke to reach the deeper parts of the lung where adenocarcinomas more frequently occur," explains Shields.
His team argues filtered cigarettes are far more dangerous than unfiltered ones for four main reasons. Their research shows filter ventilation:
- Increases the risk of lung adenocarcinoma.
- Alters tobacco combustion, increasing the amount of inhaled toxic chemicals.
- Makes smokers inhale more smoke to maintain their nicotine intake.
- Popularize a false perception of lower health risk from "light" cigarettes.
In view of their results, the scientists urge the U.S. Food and Drug Administration (FDA) to tighten regulations on "light" cigarettes.
"The analysis strongly suggests that filter ventilation has contributed to the rise in lung adenocarcinomas among smokers. Thus, the FDA should consider regulating its use, up to and including a ban," concludes the study.