Low Health Literacy Linked to Higher Tobacco Use in Korean Adults, Study Finds

Tobacco remains one of the world’s most stubborn public health problems, killing millions of people each year through diseases that are almost entirely preventable. In South Korea, a country that once enjoyed a steady decline in smoking rates, progress has visibly stalled, and the landscape of nicotine consumption has grown far more complicated. Conventional cigarettes now share the market with heated tobacco products and electronic cigarettes, and a substantial share of the adult population struggles to understand basic health information. A new population-based study published in BMC Public Health suggests these two trends may be intertwined: adults with inadequate health literacy appear significantly more likely to use tobacco, and especially more likely to use multiple nicotine products at once.

The research, conducted by Jinwook Yang, Daesung Lee, and Kyenghee Kwon of Dongguk University, drew on data from the 2023 and 2024 Korea National Health and Nutrition Examination Survey, known as KNHANES. This ongoing national survey, run by the Korea Disease Control and Prevention Agency, combines health interviews, physical examinations, and laboratory measurements to build a representative picture of the Korean population. From it, the researchers assembled an analytic sample of 11,346 adults aged 19 years or older, a size large enough to detect meaningful differences across tobacco use patterns while controlling for a wide range of demographic and health-related factors.

Health literacy, the central variable of the study, refers to a person’s capacity to obtain, understand, and apply health information in everyday decisions. The researchers measured it using a ten-item self-reported instrument, with total scores of 30 or higher classified as adequate. Respondents falling below that threshold were considered to have inadequate health literacy. This kind of measurement matters because health literacy is not simply a proxy for education; it captures how well people navigate medication labels, prevention messages, and the increasingly crowded information environment surrounding newer nicotine products, where marketing claims about reduced harm can be difficult for consumers to evaluate.

To characterize tobacco use, the team classified participants into three categories: non-current users, single-product users, and multiple-product users, based on their current use of conventional cigarettes, heated tobacco products, and electronic cigarettes. They also examined two cessation behaviors: whether a participant had attempted to quit within the past year, and whether they intended to quit within the next six months. This dual focus is notable, because much of the existing literature treats smoking as a single behavior, whereas the modern nicotine market allows consumers to combine products in ways that may carry distinct risks and may respond differently to public health messaging.

The statistical approach reflected the complexity of the survey design. Because KNHANES uses a stratified, multistage sampling framework, the researchers employed complex sample multinomial and binomial logistic regression analyses, adjusting for sex, age, educational attainment, household income, survey year, perceived stress, weight status, and chronic disease status. Multinomial models were used to compare single-product and multiple-product users against non-current users, yielding relative risk ratios, while binomial models assessed the cessation outcomes. Sensitivity analyses were then conducted to test whether the findings held up under alternative assumptions, and they did, strengthening the credibility of the central results.

The headline finding is striking in its clarity. Inadequate health literacy was associated with a 24 percent higher relative likelihood of single-product tobacco use compared with non-current use, with a relative risk ratio of 1.24 and a 95 percent confidence interval of 1.09 to 1.42. The association was even stronger for multiple-product use, where the relative risk ratio rose to 1.43, with a confidence interval of 1.13 to 1.82. In practical terms, adults who struggle to understand health information were not only more likely to smoke at all; they were disproportionately likely to be layering cigarettes, heated tobacco, and e-cigarettes together, a pattern that public health experts generally view as particularly concerning because it can sustain or even deepen nicotine dependence.

Just as revealing is what the study did not find. Health literacy showed no significant association with either past-year quit attempts or the intention to quit within six months. In other words, people with lower health literacy were more likely to use tobacco, but once they were users, their motivation to quit appeared similar to that of their more literate peers. The authors interpret this as evidence that the role of health literacy differs across tobacco-related outcomes: it may shape who enters and remains in the pool of tobacco users, yet it does not by itself determine whether those users try to break free. That distinction carries real weight for policy, because it suggests the problem lies less in motivation than in the upstream conditions that foster tobacco use in the first place.

Why would limited health literacy push people toward tobacco, and toward product combinations in particular? The authors point to the mechanics of health communication. Anti-smoking campaigns, warning labels, and cessation resources all presuppose an ability to read, interpret, and act on health information. When that ability is compromised, the persuasive and protective functions of such messaging weaken. Meanwhile, newer products such as heated tobacco devices and e-cigarettes are often marketed with technical language and claims of reduced harm that require a degree of health literacy to critically assess. Consumers with inadequate literacy may be more vulnerable to such claims, and the proliferation of flavored and technologically styled devices may lower the perceived barriers to experimentation, eventually culminating in the use of several products simultaneously.

The Korean context sharpens the significance of these results. Despite decades of successful tobacco control, the decline in smoking has recently stalled, and the market share of heated tobacco products and electronic cigarettes has grown rapidly, particularly among younger adults. At the same time, a substantial proportion of Korean adults report inadequate health literacy. The convergence of these trends creates a potential feedback loop in which the populations least equipped to evaluate health information are the most exposed to a diversifying nicotine market. Because the study is cross-sectional, it cannot establish causation; it is possible that tobacco use itself, or the conditions that lead to it, also degrade health-related understanding. Still, the robustness of the associations across sensitivity analyses, and the careful adjustment for education and income, make a compelling case that health literacy is an independent marker of tobacco-related risk.

The authors conclude that tailoring tobacco-related health communication to different health literacy levels, combined with comprehensive cessation support, may contribute to more effective tobacco control. In practice, that could mean simplifying warning labels and cessation materials, deploying visual and verbal channels that do not depend on high reading proficiency, and ensuring that quitline and counseling services are accessible and comprehensible to everyone. The finding that quit intentions are not lower among those with inadequate literacy is, in a sense, encouraging: the desire to quit appears broadly shared, and the task for public health is to build an information environment and support system that meets people where they are. As nicotine products multiply and evolve, the study suggests that the fight against tobacco will increasingly be won or lost not only through taxation and regulation, but through the clarity of the messages that reach the people who need them most.

Subject of Research: The association between health literacy, tobacco use patterns, and cessation behaviors among Korean adults

Article Title: Association between health literacy, tobacco use patterns, and cessation behaviors among Korean adults: a population-based cross-sectional study

Article References: Yang, J., Lee, D., & Kwon, K. (2026). Association between health literacy, tobacco use patterns, and cessation behaviors among Korean adults: a population-based cross-sectional study. BMC Public Health. https://doi.org/10.1186/s12889-026-29786-9

Image Credits: AI Generated

DOI: 10.1186/s12889-026-29786-9

Keywords: health literacy, tobacco use, smoking cessation, electronic cigarettes, heated tobacco products, multiple-product use, KNHANES, South Korea, public health, health communication, cross-sectional study, BMC Public Health