Tuesday 4 May 2021

Is there any public health benefit to menthol-flavoured vaping liquids?

This post reviews the rationale for banning menthol flavourings in vaping liquids.

Background and context

Since the legalization of vaping products as unlicensed consumer goods in May 2018, the use of these products by young Canadians has grown rapidly, and concerns have increased about their usefulness as cessation aids or harm reduction products.  

Because flavourings are one of the major reasons young people say they use vaping products, many Canadian governments are considering restricting or banning flavourings in vaping liquids. Five jurisdictions (BC, SK, ON, NS, PEI) have implemented restrictions on flavoured vaping products, and two more (QC, PEI, NWT) have indicated their intention to do so. 

A variety of regulatory approaches are being explored and implemented. These include:

  • Banning characterizing flavours and/or banning specific additives.
    Two provinces (Nova Scotia and Prince Edward Island) ban all flavours except tobacco flavour. Nova Scotia's measures came into force on April 1, 2020 and PEI's came into force in March 2021. The federal Tobacco and Vaping Products Act currently prohibits the promotion or sale of vaping liquids with names that are associated woth confectionary, deserts, cannabis, energy drinks or soft drink. It also bans certain additives in vaping liquids (caffeine, dyes, nutrients, vitamins, glucuronolactone, taurine and probiotics). The federal government has indicated that it will develop additional restrictions on vaping liquids this spring, as has Quebec.
  • Restricting where flavoured vaping liquids can be sold 
    Two provinces (Ontario and Saskatchewan) have adopted policies to allow non-specialty stores to sell only two flavours: tobacco and menthol. One province (British Columbia) allows non-specialty stores to sell only tobacco flavours. The sale of other flavours is permitted on-line or in specialty stores in these 3 provinces.

The number of flavours in youth-friendly products is growing

Unlike other countries (like the European Union), vaping manufacturers are not required to provide notice to the government of the products that they sell. As a result, there is no Canadian inventory of the vaping flavours currently on the market. 

Nonetheless, the product offerings of the 3 multinational companies (JUUL, BAT-VUSE, JTI-Logic) show that for these top-selling youth-friendly products there are a multitude of flavour offerings in each flavour category.  Just as cigarettes are sold in brand extensions (Players, Players Bold, Player's Smooth, etc), vaping products have more than one option in each flavour space. Just as cigarettes were sold with an expanding range of sub-brands, vaping products are sold with an expanding range of sub-flavours

  • BAT sells 22 flavours, including 4 variants of tobacco flavouring and 3 mint-menthol flavours
  • JTI sells 11 flavours, including 2 tobacco flavours and 3 mint-flavours
  • JUUL sells 3 flavours, including 2 tobacco flavours and 1 mint flavour (it withdrew other flavours from Canada in 2020).
The number of flavourings offered by some companies is growing, and is greater in Canada than in other countries for the products sold here

 Menthol is a preferred flavour of young vapers 

Over the past few years, Health Canada has conducted a number of consumer studies on vaping behaviour in Canada. 

  • The Canadian Tobacco and Nicotine Survey, 2020
    Data from the first wave of the cross sectional Canadian Tobacco and Nicotine Survey, taken in the fall of 2019, has been made available by Statistics Canada for external analysis (and the second wave is expected to be released later this spring). This survey found that fruit and menthol were the first and second choice flavours for young people. So few young people said they usually smoked tobacco flavour that the results were deemed "unreportable" (#). The selection of menthol by those over 25 years of age was similarly too small to report.  
  • Environics Vaper Panel is an on-line return-to-sample survey commissioned by Health Canada. In the spring of 2020 (POR 098-19) the flavour preferences of regular vapers (those who had vaped at least once a week in the past month) were revisited. Fruit and menthol were found to be the favourite flavours of young people. (Chart below taken from data tables)

  • The Environics research also found some regional differences: Menthol flavourings were more popular in Quebec and Fruit flavourings more popular in the Atlantic Provinces (the survey was taken before Nova Scotia's flavour restrictions were implemented.

  • Research conducted in 2020 and 2021 by Mohammed Al-Hamdani and colleagues with the support of the Lung Association, Heart and Stroke Foundation and provincial tobacco control commissions produced similar results. In an on-line survey of more than 3,000 Canadian youth and young adults, aged 16 to 24, very few identified tobacco as their most used flavour. The most popular flavour categories fruit (berry and mango) and mint-menthol. 

  • Canadian research, as shown above, is consistent that the only flavour not preferred by young people is tobacco flavouring

Menthol-flavouring ingredients make e-cigarettes more addicting.

With the benefit of mandatory European ingredient reporting, Dutch researchers [1] were able to identify which vaping flavours contained chemical menthol and also which additives were included in menthol-flavoured vaping products. This information is helpful to the two main regulatory approaches to restricting flavours: a) prohibiting the use of certain additives (eg. Health Canada), b) prohibiting the use of characterizing flavours (eg Nova Scotia).

From this very European analysis, the 6 major flavourings in vaping liquids labelled as menthol or mint were menthol (59% of liquids; median concentration of 57 mg/10ml), menthone (17%; 23 mg/ml), ethyl maltol (13%; 0.74 mg/10ml), vanillin (12%; 1 mg/10ml), eucalyptol (11.5%; 7 mg/10ml) and peppermint oil (11%; 10 mg/10ml). 

The researchers conclude that these (and other) flavour ingredients are found to increase the addictiveness of e-cigarettes because they   
"enhance the rewarding and reinforcing effects of nicotine in e-cigarettes in young adult smokers. [60, 61] For example, menthol and the green apple flavoring, farnesene, facilitate nicotine dependence through upregulation of nACh receptors in the brain [62,63]. Furthermore, flavorings reduce the nicotine metabolism (e.g., menthol, cinnamaldehyde and benzaldehyde) [64,65] and are known to facilitate inhalation and nicotine uptake due to their cooling and bronchodilating effects (e.g., menthol, theobromine and eucalyptol) [62.] In addition, flavorings such as vanillin, ethyl vanillin, and coumarin inhibit monoamine oxidase enzymes, which results in a delayed degradation of dopamine in the brain, an extended feeling of pleasure, and an increase in reinforcing behavior 66,67. ....In summary, flavors stimulate palatability as well as reward from nicotine in e-cigarettes, and, hence, contribute to nicotine dependence not only through their physical properties (e.g., cooling) but also through their history of associative learning."

Health Canada has previously acknowledged this. When publishing its 2017 regulation to ban menthol in cigarettes, it reported: "Menthol in tobacco products has numerous pharmacological effects, one of them being to mask the irritating effect of tobacco smoke, making it easier to inhale, which facilitates experimentation among novice users. Promoting experimentation among youth increases the potential for continued tobacco use that leads to addiction and an increased risk of tobacco-related diseases."


[1] Erna JZ Krusemann. The role of flavours in attractiveness of electronic cigarettes. PhD Thesis, 2021.