Cigarette filters introduced in the 1960s to reduce the health risks associated with smoking have actually increased the likelihood of lung cancer, researchers say.
The study published in the Journal of the National Cancer Institute upends the perception by smokers that they are consuming a safer product and is already leading to calls for governments to regulate the design of cigarettes.
Curtin University professor of health policy Mike Daube said it was “one of the most important papers on tobacco in recent years” and urged the government to control the product and its promotion through legislation.
“There is a long history of tobacco industry fraud in relation to lower tar products, and of consumer perceptions that modern filters somehow make cigarettes less harmful,” Professor Daube said.
“Now it turns out that they are likely to increase the risks of smoking.
“Getting rid of filter ventilation would reduce the harm and make cigarettes less appealing to young smokers – a win-win outcome for everyone except Big Tobacco.”
Modern cigarette filters contain tiny ventilation holes designed to dilute the smoke with air, based on the theory that this would reduce the amount of tar yielded by the cigarette and therefore reduce smoking risks.
But since the design was perfected in the 1960s, the incidence of lung adenocarcinoma – a type of lung cancer – has risen among smokers and makes up about 60 per cent of non-small cell lung cancer.
Researchers at Ohio State University reviewed internal tobacco company documents and published scientific literature, giving more weight to the most relevant and best studies, to provide an overview of the relationship between filter ventilation and lung adenocarcinoma.
They found that filter ventilation did result in lower tar yields, but the cigarette burnt down less rapidly so there were more puffs per cigarette and there was more time for the coal to smoulder and form toxic constituents.
Smokers also took deeper puffs, inhaled larger particles and smoked more cigarettes a day.
“The use of ventilation in the filters of cigarettes has failed to make cigarettes safer, and more than likely has made them more harmful,” the authors concluded.
“The [US Food and Drug Administration] now has the authority to require the elimination of filter ventilation because ventilation does not serve any public health purpose and instead provides a false promise of reduced risk.”
Cancer Council Australia head of public policy Paul Grogan said the study added weight to calls in Australia for legislation surrounding the composition of tobacco products, following plain packaging laws that came into effect in 2012.
The implied health benefit of filter ventilation followed a pattern of misleading marketing by tobacco companies, including cigarettes branded “light” or “mild”, which were banned from product descriptions in 2005.
“The tobacco industry is notorious for seeking to exploit every possible loophole in any public health measure designed to reduce consumption,” Mr Grogan said.
“There’s a case to talk to government about another legislative reform agenda to pick up some of these things.”
Health Minister Greg Hunt has been contacted for comment.