Are Disposable Vapes Hiding a Sweet Trap?

Medscape

4 hours ago

A recent study from Yale University, New Haven, Connecticut, and Duke University School of Medicine, Durham, North Carolina, found that the artificial sweetener neotame is present in many popular disposable electronic cigarettes (e-cigarettes) sold in the US, regardless of whether they contain nicotine. Neotame is several times sweeter than sugar or aspartame, and some products in European Union markets also contain it.
Although the additive is considered safe in food, reliable data on its inhalation are lacking, which is a critical knowledge gap, given its prevalence in e-cigarettes.
A spokesperson for the Federal Institute for Risk Assessment told Medscape Medical News , 'The Federal Institute for Risk Assessment has not yet addressed neotame in its assessments of e-cigarettes and has no information on its prevalence in e-cigarettes on the German market.'
Manufacturers of tobacco and nicotine products have always relied on flavours to enhance the taste of their products and to appeal to young consumers. Sweet, fruity, and cooling additives are widely used in e-cigarettes. They not only enhance the appeal but also raise the likelihood of trials. Despite their key role, sweeteners in these products remain unregulated in both the US and Europe.
Recently, neotame has received particular attention due to its unique properties. This chemical substance is 7000-13,000 times sweeter than table sugar and 35-65 times sweeter than aspartame. E-cigarette manufacturers prioritise neotame for its intense sweetness and thermal stability. It is used particularly in fruity or menthol-like 'cooling' flavours to intensify the taste and create a pleasant vaping experience. One example is the Cherry Lemonade flavour offered by the brand Tauro Vape.
Study
The researchers investigated which e-cigarettes available in the American market contained neotame. Their focus included the most commonly used disposable products, nicotine-free e-cigarettes, devices with synthetic nicotine analogues such as 6-methyl nicotine, and products either approved by the US Food and Drug Administration (FDA; eg, Vuse and NJOY) or submitted for approval (eg, JUUL). In most cases, neotame was not listed in the outer packaging.
A total of 73 e-cigarettes sold in the US were analysed to check for the presence of neotame. These included 11 popular disposable brands, 4 nicotine-free products, 2 with synthetic nicotine analogues such as 6-methyl nicotine, all FDA-approved cartridge systems (eg, Vuse and NJOY), and two products purchased in 2021. Most packaging did not list neotame. For comparison, the team assessed a commercially available mint candy.
Scientists dissolved e-liquids in methanol or water and measured the neotame using liquid chromatography-mass spectrometry. Furthermore, gas chromatography was used to detect nicotine, menthol, and synthetic cooling agents similar to menthol but without its typical taste, such as WS-3 and WS-23.
Neotame and Toxicology
Neotame was detected in 57 of the 73 e-cigarette samples (78%). The average concentration was 1.75 µg/mg of liquid, which is approximately 4.6 times higher than the neotame concentration in a strongly flavoured mint candy used as a comparison product. Neotame was found in all tested disposable products, all nicotine-free e-cigarettes, and all devices containing the nicotine analogue 6-methyl nicotine. In contrast, neotame was not detected in any of the FDA-approved cartridges, such as those from Vuse, NJOY, or any JUUL device.
Two of the four e-cigarettes purchased in 2021 suggested that neotame has been increasingly established in e-cigarettes for several years. Devices with 6-methyl nicotine showed particularly high levels (average 2.69 µg/mg, range up to 18.3 µg/mg).
The study indicated that neotame is deliberately used to optimise flavour, thus making e-cigarettes more appealing to adolescents and young adults. Previous research has shown that sweetening and cooling additives, such as sucralose or menthol, can significantly enhance the appeal and addictive potential of e-cigarettes.
However, some crucial questions remain. 'We don't even know exactly how much of the neotame in the liquids ends up in the aerosol of an e-cig,' said Hanno C. Erythropel, PhD, lead author and research scientist at the Department of Chemical and Environmental Engineering, Yale University. 'And how much of that neotame actually reaches the sweet taste receptors to produce a sweet sensation? These are complex questions influenced by the type of e-cigarette, the power output of the device, the design of the device, and the user's puffing behaviour — to name just a few factors.'
Heat during evaporation could produce chemical degradation products whose effects on the lungs, immune system, or central nervous system have not yet been studied. The relative heat stability of neotame compared with that of other sweeteners likely explains its use by manufacturers and poses a potential risk to consumers.
Regulation Push
In light of these findings, researchers have advocated the stricter control of sweetening additives in e-cigarettes. Disposable products, popular among youth and often containing high-potency sweeteners such as neotame, are of particular concern. From a scientific perspective, this is concerning, as even nicotine-free versions could have a significant addictive potential due to their appealing taste.
Therefore, researchers urge comprehensive studies on the toxicological effects and abuse potential of these substances. Only on this basis can a decision be made as to whether neotames should be more strictly regulated or banned in the future.