Ecigs: Potential health threats build up

To get insights in the risks associated to the use of the New and Emerging Tobacco Products the organizer Daniel Conklin (University of Louisville) and co-organizer Judith Zelikoff (New York University) invited the public health specialist Neal Benowitz (University of California, San Francisco) to chair a special session during the American Association for the Advancement of Science (AAAS) annual meeting, on February 12, 2016.

Both organizers and Ilona Jaspers (University of North Carolina, Chapel Hill) did presentations of their ongoing research during which the list of potential health threats of emerging tobacco products built up.

E-cig products may lead to new risks for health

The researchers presented their most recent studies on the effects of vaporized e-liquids on the cardiovascular (D. Conklin), the pulmonary (I. Jaspers), and the reproductive systems (J. Zelikoff). Their conclusions indicate that vaping may not eliminate risks associated with conventional smoking “and may actually be introducing new ones”, adds Jaspers to Janet Raloff for sciencenews.org.

E-cigarette vapor and artery’s health

Conklin recalled that smoking is the major cause of avoidable death, and cardiovascular diseases account for nearly half of the overall smoking-related mortality. His team investigated the cardiovascular toxicity of tobacco products on mice, focussing on e-cigarette aerosols.They found that e-cigarette or smokeless tobacco exposure increased atherosclerosis in mice. Even more surprising was the discovery of the single or combined effects of toxic aldehydes and nicotine on arteries. The reseacher concluded that electronic cigarette vapors “could adversely impact the cardiovascular health of users”.

Flavored e-liquids and the immune function

Jaspers and her team focussed on e-liquids additives like aromas and their effects on the defensive barrier of the pulmonary tree. Their findings indicate that the respiratory immune responses was potentially decreased after exposure to e-cigarette aerosols, in a similar amplitude as for tobacco smoke. After the recent debate on butter-flavored and cherry-flavored molecules, Jaspers got interested in cinnamon-flavored e-cigarettes containing cinnamaldehyde and pointed out a significant negative effect on epithelial cell physiology and barrier function. Her ongoing research on blood natural killer cells (macrophages) revealed that cinnamon may have immune suppressive effects, unlike broccoli sprout extracts that enhances antiviral defense responses.

E-liquids, reduced reproduction potential and mental disorders

Zelikoff has addressed the question of early life exposure to alternative tobacco/nicotine products. Her team investigates how e-cigarettes affect reproduction, development and long term health. Their findings after exposure to a globally-relevant smokeless tobacco product ex-utero, in-utero and post-natally show in mice:

• decreases sperm counts,
• increasing sperm DNA damage in a mouse model.
• reduces the incidence of pregnancy
• increases the risk of fatty liver and cardiovascular risk factors in adult offspring.
• drastically reduce sperm counts and sperm mobility in juvenile offspring
• gene changes in the brain as well as altered behavior in adult male and female offspring, suggesting hyper activity or agitation.

In conclusion, the chairman, Neal Benowitz underlined the challenges of this emerging science. The studies conducted in vitro or on animal models may prefigure the potential effects of exposure to tobacco smoke and new tobacco products to the human. He concluded that there is a lot of complexity to understanding what goes into the vapors and the tissues that may be at risk. Before the general perception that vaping is safer than smoking because it contains no tar and only a few toxicants compared to tobacco smoke, the role of researchers will be to tease out: “Is this really true?”.

Zelikoff who believes in the precautionary principle added: “I would look at these animal data with a great deal of respect.” if she were pregnant.

---

I. Jaspers. Pulmonary effects of exposure to tobacco smoke and tobacco products. AAAS annual meeting. February 12, 2016.

J. Zelikoff. Reproductive and developmental effects of exposure to emerging tobacco products. AAAS annual meeting. February 12, 2016.

D. Conklin. Cardiovascular effects of exposure to tobacco products and harmful constituents. AAAS annual meeting. February 12, 2016.