Newswise — Researchers from the University of California San Diego have found that local sales bans on flavored tobacco in California are associated with reduced youth vaping over time without increasing cigarette smoking.
The findings, based on an analysis of more than 2.8 million middle and high school students, were published April 10, 2026 in JAMA Health Forum.
“Our findings suggest that local flavored tobacco bans can be an effective strategy for reducing youth e-cigarette use,” said Eric Leas, PhD, MPH, assistant professor at the UC San Diego Herbert Wertheim School of Public Health and Human Longevity Science and senior author of the study. “Importantly, we did not find evidence that these policies led young people to switch to cigarettes, which has been a major concern raised in policy debates.”
Electronic nicotine delivery systems (ENDS), commonly known as e-cigarettes or vaping products, have been widely used by adolescents in the U.S. National data show that youth vaping peaked in 2019 when more than a quarter of high school students reported using e-cigarettes, though prevalence has since declined. Despite this decrease, frequent use remains common among current users, raising concerns about nicotine dependence and long-term health risks.
One approach policymakers have used to reduce youth vaping is restricting the sale of flavored tobacco products, which often include fruit, candy or mint flavors that appeal to young users. Prior research has shown that flavored products are a major driver of youth e-cigarette use.
To better understand the impact of these policies, the research team analyzed responses from 2,805,708 students who participated in the California Healthy Kids Survey between 2017 and 2022. The survey includes students in grades 7, 9 and 11 and asks about past-month use of tobacco products.
The researchers compared tobacco use among students attending schools in jurisdictions with flavored tobacco bans to those in areas without such policies. The study used a dynamic difference-in-differences design to account for variations in when different cities adopted the bans and to track how outcomes changed over time. The dynamic difference-in-differences design method allowed researchers to see whether youth vaping changed after flavored tobacco bans were adopted in different cities — and whether those changes grew over several years, rather than just looking at a simple before-and-after comparison.
Youth vaping rates were lower in areas with flavored tobacco bans. In jurisdictions with a ban, 6.2% of students reported current e-cigarette use, compared with 7.7% in areas without one. Over time, the study found these policies were associated with sustained declines in youth vaping.
By contrast, the study found no meaningful association between flavored tobacco bans and cigarette smoking among youth. Cigarette use remained roughly the same in jurisdictions with and without the policies.
The delayed reductions in vaping may reflect how policies evolve and are enforced over time. Many local jurisdictions gradually strengthened their rules after initial adoption, for example by expanding definitions of flavored products or adding enforcement provisions. Resources and support for enforcing these laws also grew over time, particularly after California’s statewide ban took effect, helping local communities better implement the restrictions.
California voters approved a statewide flavored tobacco sales ban in 2022, which took effect in 2023. Because many cities had implemented their own restrictions years earlier — some as early as 2011 — the researchers say these local policies provide an opportunity to study longer-term impacts of flavor bans.
The authors note that the study focused on California, a state with historically strong tobacco control policies and relatively low youth smoking rates compared with other states. As a result, the magnitude and timing of the effects may differ in places with different policy environments.
Future research will be needed to understand the long-term impact of statewide bans and how similar policies affect youth tobacco use across different regions and communities.
“Local policies gave us a valuable window into how flavored tobacco restrictions may influence youth behavior over time,” said Giovanni Appolon, MPH, first author of the study who conducted this research as part of experiential learning as doctoral candidate in the UC San Diego – San Diego State University Joint Doctoral Program in Public Health. “As more jurisdictions adopt these policies, continued monitoring will help determine how enforcement, policy design and community context shape their public health impact.”
Additional co-authors on the study include: David Strong, PhD, Dennis R. Trinidad, PhD, from UC San Diego Herbert Wertheim School of Public Health and Human Longevity Science. Heather A. Pines, PhD, S. Wilton Choi, PhD, and Eyal Oren, PhD, from San Diego State University.
The study was funded by the Tobacco-Related Disease Research Program (Grant # T34DT8325).
