Cigarette smoking in the United States has fallen to historic lows, yet overall tobacco use has not dropped as sharply. New research from the MUSC Hollings Cancer Center points to a key reason: nicotine consumption is increasingly shifting from combustible cigarettes to noncombustible products, especially e-cigarettes, among younger adults.
The study, published in JNCI Cancer Spectrum, reframes tobacco risk by focusing on what people use rather than only whether they use tobacco. Because smoking-related cancers are driven largely by combustion—responsible for most tobacco-related cancer deaths—tracking product substitution is essential for forecasting future disease burden.
Lead author K. Michael Cummings and colleagues describe the central pattern: exclusive cigarette use is being replaced mainly by exclusive use of other combustible products, with e-cigarettes playing a major role. In contrast, dual use remains rare, suggesting that many users are not simply layering vaping on top of smoking.
To capture national trends, the researchers analyzed data from the National Health Interview Survey, covering U.S. adults from 2015 through 2023. Unlike earlier summaries that grouped all tobacco together, the team separated products into combustible categories (such as cigarettes, cigars, pipes, and hookahs) and noncombustible categories (such as e-cigarettes, smokeless tobacco, and nicotine pouches), while also measuring dual use.
The results show steep declines in exclusive combustible use across nearly all age groups, with the strongest reductions among adults aged 18 to 34. Over the same period, exclusive noncombustible use rose, driven largely by electronic cigarettes. Dual use, however, stayed remarkably stable at low levels.
A crucial age divide emerges. While younger adults increasingly move away from combustion, adults aged 55 and older continue smoking cigarettes more often and show slower uptake of noncombustible alternatives.
The team developed a population harm-reduction index to quantify whether substitution at the population level is shifting exposure away from combustion. By comparing the prevalence of exclusive noncombustible use against the prevalence of any combustible use, the index increases as more people replace burned tobacco with alternatives believed to deliver fewer cancer-causing chemicals.
Among adults aged 18 to 24, exclusive noncombustible use exceeded any combustible use—the strongest signal of a beneficial substitution trend. Researchers caution, however, that no nicotine product is risk-free; the healthiest options remain not starting and fully quitting.
They argue that if these generational patterns persist, smoking-related cancers could decline several decades from now, though the full impact will only become visible over long time horizons.
Subject of Research: People
Article Title: Trends in adult exclusive and dual use of combustible and non-combustible tobacco products in the United States
News Publication Date: 27-Jul-2026
Web References: http://dx.doi.org/10.1093/jncics/pkag062
References: 10.1093/jncics/pkag062
Image Credits: Medical University of South Carolina
Keywords: Tobacco, e-cigarettes, nicotine, population studies, cancer risk, harm reduction, dual use
