A comprehensive review of 123 studies involving 4 million participants under 29 found no definitive evidence that vaping leads to cigarette smoking among youth. Published in the journal Addiction, the research challenges the widely debated “gateway theory” and highlights the complexity of understanding vaping’s impact on smoking behaviors.
“Some evidence suggests vaping may contribute to declining youth smoking rates, particularly in the U.S.,” said Jamie Hartmann-Boyce, senior author and assistant professor at the University of Massachusetts Amherst. “But the data is open to multiple interpretations, and we need more studies to establish causal links.”
The Gateway vs. Diversion Debate
Public health experts remain divided on whether vaping acts as a gateway to smoking or diverts youth away from traditional cigarettes. A third theory posits that vaping and smoking share common risk factors without a direct causal relationship. However, empirical evidence supporting any of these hypotheses remains limited.
The review analyzed data from the U.S., Canada, and Western Europe, revealing mixed findings. While some studies linked increased vaping rates to declining smoking rates, others showed no clear connection or even the opposite trend.
“You can’t randomize kids to vape or not vape—it’s unethical,” Hartmann-Boyce explained. “This makes it challenging to draw definitive conclusions from observational studies.”
Youth Smoking Rates Continue to Decline
Despite concerns about vaping, youth smoking rates have plummeted over the past decade. CDC data shows that high school students reporting cigarette use in the past 30 days dropped from 15.8% in 2011 to 1.7% in 2024.
“If vaping were causing kids to start smoking, we’d see it in population-level data,” Hartmann-Boyce noted. “But we haven’t observed that trend.”
At the individual level, youth who vape are more likely to smoke later compared to those who never vape. However, it’s unclear whether vaping causes this transition or if these individuals would have become smokers regardless.
Implications for Public Health Policy
The findings have significant implications for policymakers balancing youth protection with harm reduction for adult smokers. While tighter regulations may curb youth vaping, they could also limit access to e-cigarettes for adults seeking to quit smoking.
“Nicotine e-cigarettes can help adults quit smoking, but we need to ensure they don’t appeal to youth,” said Monserrat Conde, lead author from the University of Oxford.
The Need for Further Research
The review underscores the need for more robust studies to clarify vaping’s long-term effects. “Current evidence doesn’t conclusively support the gateway theory,” Hartmann-Boyce said. “But we must remain vigilant and continue monitoring trends.”
