Smokers who switch from conventional cigarettes to heated tobacco products (HTPs) may substantially reduce their exposure to chemicals linked to lung disease and lung cancer, according to a new review of recent medical studies, adding to the growing body of research on tobacco harm reduction.
The review, titled ‘Heated Tobacco Products: Current Evidence of Pulmonary Harm and Lung Cancer Risk,’ analyzed 26 studies published from January 2020 to June 2025 and found that people who use HTPs are generally exposed to fewer toxic compounds than cigarette smokers.
It also cited risk-estimation models indicating that the excess lung cancer risk associated with HTP use could be around 3 to 4 percent of that seen among conventional cigarette smokers.
Published in April in the US-based peer-reviewed medical journal Cureus, the review reported substantially lower exposure to carcinogens and more favorable biomarkers of potential harm among HTP users than among cigarette smokers. The findings, the researchers said, support existing evidence that removing the combustion process significantly reduces exposure to many of the toxic substances produced by cigarette smoke.
The review was conducted by researchers from the Department of Family Medicine at Unidade de Saúde Familiar in Portugal, a primary care institution focused on family medicine, preventive healthcare and health promotion.
Several Filipino health professionals said the findings contribute to a growing body of evidence supporting tobacco harm reduction as part of efforts to address smoking-related diseases.
‘More countries, including the Philippines, are now embracing tobacco harm reduction as a compassionate but effective way of addressing the smoking epidemic as we explore the next steps toward the future,’ said Prof. Ron Christian Sison, lead convenor of the Harm Reduction Alliance of the Philippines.
Dr. Fernando Fernandez, former president of the Asia Pacific Dental Federation and the Philippine Dental Association, said the review reinforces the need to encourage smokers who are unable to quit to move away from combustible tobacco products.
‘The evidence continues to show that the greatest harm comes from burning tobacco,’ Fernandez said. ‘For smokers who are unable to quit, switching to less harmful alternatives can significantly reduce exposure to toxic substances associated with cigarette smoke.’
He noted that the Philippines has enacted legislation recognizing tobacco harm reduction, saying it provides a framework for educating patients about alternative nicotine products while complementing broader public health measures to reduce smoking-related illnesses.
Unlike conventional cigarettes, HTPs electronically heat processed tobacco at controlled temperatures instead of burning it. According to the review, this process reduces emissions of harmful and potentially harmful chemicals by more than 90 percent compared with cigarette smoke, based on industry figures cited by the researchers.
The review said available evidence indicates that HTPs can reduce smokers’ exposure to harmful chemicals when compared with continued cigarette use.
For urologist Dr. Rogelio Varela Jr., tobacco harm reduction should be part of discussions with smokers who struggle to quit.
‘If a smoker cannot quit immediately, we should help lessen the harm,’ Varela said. ‘This review suggests that moving away from cigarettes reduces exposure to dangerous chemicals. While it doesn’t eliminate all risks, reducing exposure is a crucial step for those who would still continue the habit.’
The researchers also noted that many smokers perceive HTPs to be less harmful than conventional cigarettes, a factor that may encourage some to switch.
They stressed, however, that HTPs are not risk-free. The products can still trigger biological changes associated with inflammation and oxidative stress, while much of the existing evidence is based on biomarker studies rather than long-term clinical outcomes.
The authors concluded that HTPs may offer a lower-risk alternative for smokers who would otherwise continue using conventional cigarettes, including the possibility of a reduced risk of lung cancer, although further research is needed to better understand their long-term health effects.