You know that cigarette smoking is the No. 1 risk factor for lung cancer (and a host of other serious diseases). However, if you do choose to smoke, you may wonder if filtered cigarettes are a safer alternative than unfiltered cigarettes. They’re not. In fact, there’s a major effort underway to convince the Food and Drug Administration to ban cigarette filters with holes in them.

In 1964, the Surgeon General’s report stated that smoking caused lung cancer. Tobacco companies were encouraged to make changes in their product to reduce damage to smokers, says Dr. James Davis, medical director at the Duke Center for Smoking Cessation.

[See: What Not to Say to Someone With Lung Cancer.]

The tar in cigarette smoke had known carcinogens (cancer causing agents), so it was a reasonable idea that reducing tar content would lower lung cancer risk. To do this, manufacturers added tiny holes in their filters. When a smoker inhales, these holes bring in outside air along with the smoke. The filters help trap tar, and the highly porous filter paper also allows toxic chemicals to escape. “If you combine air with smoke, you expect to get less smoke and less carcinogens,” Davis says.

Almost all cigarettes sold have these filters with holes, says Dr. Peter Shields, lead investigator and deputy director of The Ohio State University Comprehensive Cancer Center — Arthur G. James Cancer Hospital and Richard J. Solove Institute. “Regular cigarettes have them. Light cigarettes have them, but more. Ultra light cigarettes have them even more. [The filters] made the smoke smoother, so smokers thought [these cigarettes] were healthier.”

When scientists analyzed smoke from filtered cigarettes on a smoking machine — a device that mimics a person smoking — they did show more air and less tar. “It made sense to everyone that [the holes in filters] were helpful,” Davis says.

It turns out, however, that when scientists looked at lung cancer rates by when people were born, they found that despite an overall decrease in lung cancers, the rate of new adenocarcinomas, a certain type of lung cancer, was increasing.

“In the 60s and 70, the most common type of lung cancer was squamous cell carcinomas [which accounted for about two-thirds of cases]. Now, two-thirds of lung cancers in men are adenocarcinomas,” Shields says. Since women really started smoking en masse in the 1970s, after the implementation of filters with holes, they primarily developed adenocarcinomas lung cancers. “The evidence was absolutely clear that adenocarcinomas were going up when they shouldn’t be,” Shields says.

[See: 7 Things You Didn’t Know About Lung Cancer.]

Cigarettes burn differently with ventilation holes, Shields says. You actually get more — not less — bad chemicals. Furthermore, because smokers are addicted to nicotine and get less of it with filtered cigarettes, they compensate by smoking more and taking bigger, deeper puffs, thus inhaling more smoke, more deeply into the far corners of the lungs where adenocarcinomas develop. Smoking machines, researchers learned, do not mimic how real people actually smoke.

According to Davis, it’s difficult to say with certainty if there’s a causal relationship between filter holes and the high rates of adenocarcinomas. “It’s hard to say one thing causes another,” he says, “but by my reading of the evidence, it’s really strong. We don’t wait to see [data showing] bold causality when we see a strong relationship that’s causing real harm. The scientific community should be concerned.”

While the FDA can’t outright ban cigarettes, it has the jurisdiction to regulate cigarette manufacturing, including these filters. There’s no evidence that the holes help or provide a health benefit, and it appears they’re harmful. “If the FDA regulates filters, smokers may be cognizant of what they are smoking,” Shields says. “Don’t be fooled by smooth smoke. If [the smoke] is harsher, maybe [smokers will] smoke less or quit altogether.”

Cigarette manufacturers cannot use terms such as light or mild to market cigarettes, so they work around this by using colors — such as white, which research suggests signifies safety — to signify differences among cigarettes. Smokers recognize these differences and, when they choose one of these cigarettes, believe they’re smoking a less dangerous product.

“It appears there are real downsides to the holes,” Davis says. “They expose cells deep in the lungs to carcinogens and appear to be related to higher incidence of lung cancer. The FDA would be wise to pay attention.”

[See: 7 Innovations in Cancer Therapy.]

“There are no cigarettes that are safe — filtered, unfiltered, natural tobacco,” Davis says. “Filtered cigarettes do remove some of the carcinogens, but the holes in the filters look like they are causing problems. If you have to smoke, it’s a little better to smoke with a filter. The only smoking change that makes a difference is quitting. Sixty-nine percent of smokers die of an illness related to smoking. There’s overwhelming evidence that smoking is associated with heart disease, lung disease, 13 types of cancers. Nowadays, there are terrific ways of getting help to quit.”

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Do Filtered Cigarettes Lower the Risk of Lung Cancer? originally appeared on usnews.com