Critical Review of Heated Tobacco Products: A Systematic Review

A recent systematic review of animal studies on heated tobacco products (HTPs) has highlighted inconsistencies in outcomes and variability in experimental design, complicating regulatory assessments of their safety. The review, conducted by researchers at LCI Science, Oak Ridge, NC, aimed to assess the methodology and determine areas for future refinement of animal studies on HTPs. The study included 48 animal studies on HTPs, with 28 reporting lower toxicological effects compared to cigarettes, while 20 did not support HTPs as safe or risk-reduced alternatives.

Key Takeaways:

The systematic review of animal studies on HTPs included 48 studies, of which 28 reported lower toxicological effects compared to cigarettes.
Of the included studies, 20 did not support HTPs as safe or risk-reduced alternatives to cigarettes.
Continuous HTPs exposure or switching from cigarette to HTPs significantly reduced exposure effects associated with cigarette smoking.
Many studies' conclusions were positive with regard to reduced risk in comparison to tobacco smoking.
However, HTPs cannot be considered definitively 'safe' tobacco products, as current data remain insufficient for assurance of absolute reduced health risks in comparison to not smoking.

The researchers concluded that there is an urgent need for more high-quality animal studies, particularly from non-tobacco stakeholders, to better assess the in vivo risk of HTPs.

Statistics:

The review included 48 animal studies on HTPs.
28 studies reported lower toxicological effects compared to cigarettes.
20 studies did not support HTPs as safe or risk-reduced alternatives to cigarettes.
The risk of bias tool Systematic Review Center for Laboratory Animal Experimentation was used to assess the bias of methodology and outcomes.

Sources:

Rana Tayyarah et al. (2025)
Nicotine and Tobacco Research, 2025
Oxford University Press, Great Clarendon St, Oxford OX2 6DP, England
www.oup.com/
ntr.oxfordjournals.org