Lead researcher Dr. Graham Eyres, who is considerably experienced in researching food flavours, said that flavour substances currently being added to the liquids are regulated under the Food Standards Code. However, he added, the code only covers food flavours, not vape flavours.
“E-cigarettes heat a liquid into an aerosol or vapour cloud that is inhaled by the user, typically delivering doses of nicotine to the lungs,” said Dr Eyres. “In New Zealand, the range of flavourings added to the liquids in e-cigarettes have not been characterised or quantified. This is concerning because some of the volatile organic compounds generated during vaporisation may be directly harmful if inhaled at high concentrations or may degrade to form harmful compounds.”
The researcher referred to the use of diacetyl as an example. “Popcorn lung” is the popular name for Bronchitis obliterans, a chronic lung disease linked to various air pollutants. One chemical it’s been speculatively linked with is diacetyl, a naturally occurring fermentation product found in butter, red wine and various other foods. It’s also used as flavouring in some e-liquids, and while diacetyl is safe to ingest there’s some evidence it may not be safe to inhale.
Cigarette smoke contains diacetyl at levels hundreds to thousands of times higher than any e-liquid, but there has never been a single case of popcorn lung linked to smoking. It’s also a disease that takes years of exposure to develop, so some experts find the idea that anyone could get “instant popcorn lung” from vaping simply absurd.
Nevertheless, Eyres points out that while this food flavouring was discontinued, international research has shown that 74% of e-liquids contain diacetyl, with more than 40 percent at concentrations higher than the recommended safety limits.
“With this Explorer Grant, we will use methods developed in food and environmental science and redesign them to better understand what compounds are in these e-cigarette liquids and how these compounds are distributed within different-sized aerosol droplets. Armed with this knowledge, we can then work with toxicologists and health professionals to determine what the level of risk is from these compounds and hopefully provide regulators with the evidence they need to develop specifications and standards on e-cigarettes,” said Dr Eyres.
Green apple flavour
Meanwhile, research conducted at Marshall University in West Virginia in the US, found that the flavourant farnesene in green apple flavoured vaping products, triggers reward-related behavior by promoting high-sensitivity nAChRs in the ventral tegmental area of the brain. In simple terms, this means that this compound makes this flavour addictive.
“With or without nicotine, flavoured vapes pose potential risks for the brain and addiction,” said lead study author Skylar Cooper. Cooper, who is a research technician Austin Akers and her research team, split study subjects (mice) in 3 groups. One group was given nicotine, another the green apple flavourant farnesene or both, and the third a saline solution.
The researchers found that Farnesene was rewarding by itself, as mice chose the farnesene chamber over the saline chamber. However, farnesene was also found to enhance the reward level even more when mixed with nicotine.
Read Further: Scoop