Health & Studies

Heart Research Full Of Wu

Respected and experienced clinician leads flawed heart study that fails to compare risks of juice flavour agents to the smoking alternative

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“Flavourings may increase heart disease risk”, says the release from Joseph C Wu’s Stanford press office. News outlets grabbed all the salacious pieces from that headline but missed out on the ‘may’. The study falls flat as it failed to compare any risk identified with that posed from smoking.

Joseph Wu has an exceptionally impressive CV full of high-level education, influential positions and a raft of awards. He sits on an FDA Advisory Committee and frequently presents to his peers; Wu gave three presentations of his work at this February’s Society for Research on Nicotine and Tobacco conference in San Francisco.

One of the presentations focussed on this study, “Modelling Cardiovascular Risks of E-Cigarettes With Human-Induced Pluripotent Stem Cell–Derived Endothelial Cells”.

This translates to the research team looking at the investigated the effect of e- liquid flavours on endothelial cells, which line the interior of blood vessels. The team grew cell cultures in the lab and exposed them to liquids based on flavour agents and blood taken from vapers.

They say, “cells exposed to the e-liquids or blood are less viable and exhibit significantly increased levels of molecules implicated in DNA damage and cell death. The cells are also less able to form new vascular tubes and to migrate and participate in wound healing.”

Senior author Wu said: “Until now, we had no data about how these e-liquids affect human endothelial cells. This study clearly shows that e-cigarettes are not a safe alternative to traditional cigarettes. When we exposed the cells to six different flavours of e-liquid with varying levels of nicotine, we saw significant damage. The cells were less viable in culture, and they began to exhibit multiple symptoms of dysfunction.”

The reasoning behind approaching the study in this way is highlighted in the release when it introduces the nonsense that there is an epidemic of teen use: “the use of e-cigarettes has skyrocketed since their introduction about a decade ago, particularly among young people.”

Won Hee Lee also worked on the research, he said: “One in five high school students have tried e-cigarettes, perhaps because they feel they are relatively safe, but we found the e-liquids caused changes in the endothelial cells that are closely related to those seen during the development of cardiovascular disease.”

This wasn’t a study looking to quantify risk, it was a piece of work engineered to attack fruit, tobacco, sweet tobacco with caramel and vanilla, sweet butterscotch, cinnamon, and menthol. It held a primary aim of supporting the on-going illiterate push to prohibit flavours from sale because of “the epidemics”.

“When you’re smoking a traditional cigarette, you have a sense of how many cigarettes you’re smoking,” Wu said. “But e-cigarettes can be deceptive. It’s much easier to expose yourself to a much higher level of nicotine over a shorter time period. And now we know that e-cigarettes are likely to have other significantly toxic effects on vascular function as well. It’s important for e-cigarette users to realize that these chemicals are circulating within their bodies and affecting their vascular health.”

Foundation for a Smoke-Free World’s Charles A. Gardner responded: “With respect, any study that does not compare risks of smoking versus vaping is utter BS.”

“Half of smokers will die of cancer, heart or lung diseases. There are now 42 MILLION vapers in the world, almost all ex-smokers. Not one has ever died from vapour. Heart risk reduced!”

Public Health England states: “There is no clear evidence that specific e-liquid flavourings pose health risks,” and “comparative risks of cardiovascular disease and lung disease have not been quantified but are likely to be also substantially below the risks of smoking.”



  • “Modelling Cardiovascular Risks of E-Cigarettes With Human-Induced Pluripotent Stem Cell–Derived Endothelial Cells” by Wu et al., - [link]
  • “Evidence review of e-cigarettes and heated tobacco products 2018: executive summary” by Public Health England [link]
Dave Cross avatar

Dave Cross

Journalist at POTV
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Dave is a freelance writer; with articles on music, motorbikes, football, pop-science, vaping and tobacco harm reduction in Sounds, Melody Maker, UBG, AWoL, Bike, When Saturday Comes, Vape News Magazine, and syndicated across the Johnston Press group. He was published in an anthology of “Greatest Football Writing”, but still believes this was a mistake. Dave contributes sketches to comedy shows and used to co-host a radio sketch show. He’s worked with numerous vape companies to develop content for their websites.

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