Study in zebrafish finds vaping during pregnancy may affect fetus

Sometimes seen as a less harmful alternative to smoking cigarettes or cigars, vaping is currently regulated under five different pieces of legislation in Canada. What may come as a surprise to many is that the compounds used to give vape liquids their flavour are not regulated and there are more than 7,000 flavours of vape liquids available to consumers. 

“One of the problems with vaping is that all kinds of flavours are used to make it palatable — it’s not just nicotine,” says Dr. Matt Vijayan, PhD, principal investigator and professor in the Faculty of Science. “These flavourings are added to the vape, but there is no regulation on what can be used as a flavourant.”

Vijayan and one of the study’s co-authors, Dr. Alison Holloway, PhD, came up with a "proof of concept" experiment to investigate whether smoking flavoured vaping products during pregnancy would affect fetal development. Holloway, with Ontario’s McMaster University, was already studying the impacts of a mother’s exposure to nicotine, cigarette smoke and vaping on the health of developing babies during pregnancy.  Dr. Patrick Gauthier, PhD, a postdoctoral fellow in Vijayan’s lab, carried out the studies. The results were recently published in The Royal Society Biology Letters.

Vijayan and his lab team tested two commonly used flavourants (cinnamon and blueberry) and created chemical extracts to test on zebrafish, which were used as a model because they share 70 per cent gene similarity to humans. Certain genes were able to be removed from the zebrafish genome to more closely demonstrate a corresponding effect in humans.

When exposed to vape extract in the short term, the developing zebrafish showed a clear hyperactive response, which the researchers could observe and quantify. The researchers say the findings should make us cautious about whether the same effects could be happening in humans.

“What’s interesting is that the response is similar to what happens with just nicotine in the absence of flavouring,” Vijayan explains. “Nicotine is a well-established neurotoxicant, and we all know that — but we didn’t know the vape extracts have an effect on sensory-motor responses, too.”

The take-home message is that we need to be wary of the flavourants because they’re showing effects similar to those of nicotine.”

Vijayan’s next research project will involve finding out exactly which molecules are causing the response, and how.

Vijayan’s work was funded by a Discovery Grant from the Natural Sciences and Engineering Research Council of Canada (NSERC).