Researchers from the University of Bath have cast doubt on industry claims that heated tobacco products are less harmful than cigarettes, with a new study concluding that there is not enough evidence to demonstrate they are safer.
Heated tobacco products use an electronic device to heat tobacco sticks to a high temperature: they release nicotine and other chemicals, but do not emit smoke. Manufacturers such as Philip Morris International (PMI) say heated tobacco products reduce the level of harmful chemicals that users are exposed to compared to cigarettes, and promote them as a safer alternative to smoking.
But a new systematic review of 40 clinical studies on heated tobacco products, published in the peer-reviewed Tobacco Control journal, challenges that assertion head on.
“Contrary to what the tobacco industry is telling us, the clinical data on the health effects of heated tobacco is not clear cut. [The data] provides no clear indication either way as to the risks of heated tobacco products,” said the study’s lead author Sophie Braznell, a researcher at the University of Bath’s Tobacco Control Research Group.
The review’s publication comes as MPs consider the health department’s proposals for tough new tobacco controls, set out in the Control of Tobacco Products and Electronic Delivery Systems Bill. The draft legislation proposes greater restrictions on smoking in public places, introduces plain packaging and picture warnings, bans vending machine sales, prohibits point-of-sale advertising, and for the first time regulates e-cigarettes and other new-generation products in much the same way as tobacco.
The clinical studies compared biomarkers of potential harm and adverse events in adult users of heated tobacco products to those found in people who smoked, used e-cigarettes, or were non-smokers. Biomarkers of potential harm are biological measures — such as high blood pressure or white blood cell count — that indicate an increased risk of long-term health problems caused by exposure to a substance or agent.
The available research lacked the independence and quality required to draw conclusions about “real-world” uses, said Braznell. Most of the studies (29) were industry-affiliated — only nine studies lasted longer than five days, she said.
The risk of bias was deemed high for 32 of the studies, and was unclear for the rest. The researchers found mixed effects for the 143 different biomarkers of potential harm that were measured in the studies, and no significant difference in the rate of adverse events among users of heated tobacco products and people who smoked, used e-cigarettes or were non-smokers.
They concluded the data did not provide a clear indication of harm or benefit in using heated tobacco products, and said better studies that were free of industry funding were needed to determine their health effects.
PMI markets a heated tobacco product in SA called iQos. It had not responded to Business Day’s questions at the time of publication.
PMI has previously called for differentiated regulation that would allow it to have greater freedom to advertise to consumers and pay lower excise taxes than manufacturers of cigarettes.
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