The evidence is clear: flavour bans may curb youth vaping, but risk pushing smokers back to cigarettes - begging the question - what is our priority?
Tobacco harm reduction has always been about balance: finding ways to minimise risks for people who use nicotine while avoiding unintended consequences. One of the most contested questions in this field concerns the role of flavours in safer nicotine products like vapes, heated tobacco and nicotine pouches. For some, flavours are an appealing gateway that could pull in youth who might otherwise never smoke or vape. For others, they are a lifeline—making alternatives to cigarettes palatable enough that people who smoke can actually switch.
A new study by researchers at Mass General Brigham, published in JAMA Network Open, adds fresh evidence to this debate. Looking at six U.S. states—Massachusetts, New Jersey, New York, Rhode Island, Maryland, and Utah—that enacted vape flavour bans in 2020, the study examined trends in vaping and smoking from 2019 to 2023. As expected the results were not positive.
While vaping among young people and adults declined significantly in states with flavour bans, with vaping among 18–24-year-olds dropping by nearly seven percentage points in 2022, adult use by about one percentage point by 2023, and teen vaping from 24.1% in 2019 to 14.0% in 2023, compared to a decline from 24.6% to 17.2% in other states. This had a negaitive impact on smoking rates.
Banning flavours, fueling smoke
Alongside these reductions came a less encouraging trend. Not only did smoking not fall as much in the ban states, in some groups, it actually ticked upward. Youth smoking rates were almost two percentage points higher than expected in 2021, while young adults showed a 3.7 percentage point increase. This pattern confirms what THR experts have been warning us about all along: flavour bans, while curbing youth vaping, are inadvertently slowing progress on reducing smoking—the much deadlier behaviour.
The state-level differences offer further nuance. Massachusetts, which implemented local bans before its statewide law and enforced restrictions strictly, saw the clearest reductions in vaping. States with exemptions—allowing menthol or sales in specialty shops—had weaker results. Even so, none of the states showed robust declines in cigarette use after the bans.
This of course, is not the first time research has suggested that limiting flavours may have unintended consequences. A 2020 paper in Nicotine & Tobacco Research found that U.S. adults who vaped non-tobacco flavours were more likely to quit smoking than those restricted to tobacco-flavoured options. Another study in Addiction (2021) concluded that adults who switched to flavoured e-cigarettes were more successful in sustaining cigarette abstinence over time. These findings echo what many harm reduction advocates have long argued: flavours are not just cosmetic—they are functional tools for substitution.
Menthol, mango, and the math of harm reduction
Evidence from heated tobacco products (HTPs) reinforces this. A recent clinical trial published in the American Journal of Preventive Medicine tested menthol-flavoured versus tobacco-flavoured HTPs among adult menthol cigarette users. The results were striking: those given menthol HTPs cut their cigarette consumption by 80%, while those using tobacco-flavoured HTPs reduced by only 37%. The nicotine delivery and puffing behaviour were virtually identical across both groups; what made the difference was flavour. Menthol, long known to smooth the harshness of smoke, appears to make HTPs more satisfying replacements for cigarettes.
The role of flavours in substitution is not trivial. Cigarettes kill eight million people each year worldwide. Any intervention that meaningfully helps smokers leave combustion behind has major public health significance. Reviews such as the one published in the International Journal of Environmental Research and Public Health in 2024 have shown that vaping and HTPs slash exposure to toxic chemicals by more than 90% compared with cigarettes. Polycyclic aromatic hydrocarbons, volatile organic compounds, tobacco-specific nitrosamines, and carbon monoxide—all key drivers of cancer, heart disease, and respiratory illness—drop to near-undetectable levels. The difference between continuing to smoke and switching to a flavoured alternative could literally be life or death.
Of course, the concerns about youth uptake cannot be dismissed. Flavours like fruit or candy do appeal to adolescents, and experimentation is common. Yet large-scale surveys suggest that most young people who try vapes do not become daily users, and very few progress to smoking. In the U.K., where flavoured vapes remain widely available under regulated conditions, youth smoking continues to fall to record lows. This suggests that the availability of flavours, paired with age restrictions and enforcement, need not derail tobacco control progress.
Evidence vs. ideology
As usual, the challenge then is balance. Flavour bans may look attractive as a quick solution to youth vaping, but they risk removing one of the most effective incentives for adult smokers to switch. Worse, they may push people back to smoking, as the JAMA Network Open study warns. A more nuanced approach could involve restricting marketing and packaging that clearly targets youth, enforcing age verification more rigorously, and limiting the most obviously childlike flavour names—without eliminating adult-appealing options like menthol, fruit, or dessert profiles.
Ultimately, the conversation about flavours should be grounded in harm reduction. The question is not whether flavours are risk-free but whether they help more people escape the vastly greater risks of smoking. The evidence so far suggests they do. If policymakers want to protect young people while also driving down smoking-related disease, the goal should be regulation that preserves flavours as a tool for adult smokers while curbing irresponsible promotion and access by youth.
The Mass General Brigham study adds a crucial reminder: tobacco control policies don’t operate in a vacuum. As experts in the field have consistently highlighted, every lever pulled to restrict one behaviour can shift another, for better or worse. If the goal is to save lives, then the evidence points clearly to this: maintaining access to flavoured alternatives, alongside smart regulation, may be the most effective way to reduce harm across the population.