TAMPA, Fla. — While health officials and lawmakers continue trying to steer young people away from vaping, the wide variety of enticing flavors added to these products make that a tough task. Although most of the worry over vaping comes from the risk of addiction, lung damage, and threat of switching to conventional cigarettes, a new study finds the flavoring chemicals these products use may be just as harmful as anything else. Researchers from the University of South Florida Health say vaporized flavoring molecules are toxic to the heart and damage the organ’s ability to beat correctly.
While other studies find that vaping is generally less harmful than smoking traditional tobacco products, the nicotine and other chemicals in e-cigarettes still damages the heart and lungs. Until now however, researchers say the impact of flavoring additives inhaled into the bloodstream remained unclear.
“The flavored electronic nicotine delivery systems widely popular among teens and young adults are not harm-free,” says principal investigator Dr. Sami Noujaim in a university release. “Altogether, our findings in the cells and mice indicate that vaping does interfere with the normal functioning of the heart and can potentially lead to cardiac rhythm disturbances.”
Dr. Noujaim’s study is one of the first to investigate the cardiotoxic effects of flavoring chemicals added to the e-liquids in electronic nicotine delivery systems (ENDS). ENDS include a variety of different vaping products like vape pens, mods, and pods.
What happens when you vape?
Researchers define vaping as inhaling aerosols (tiny droplets) which e-cigarettes create by heating liquid nicotine and solvents like propylene glycol and vegetable glycerin. A vaping device’s battery-powered heater converts this liquid into a smoke-like mix, or vapor.
The study tested how three popular e-liquid flavors — fruit, cinnamon, and vanilla custard — affect cardiac muscle cells (HL-1) of mice. After being exposed to e-vapor in a lab dish, the results reveal all three flavors are toxic to HL-1 cells.
The USF team also examined what happens to cardiac cells grown from human stem cells that are exposed to three types of e-vapors. The first substance containing only solvents interfered with the cell’s electrical activity and beating rate. The second substance, containing both nicotine and solvents, proved to be even more toxic to the heart cells.
The third substance however, containing nicotine, solvents, and vanilla custard flavoring, caused the most damage to the heart and its ability to spontaneously beat correctly. Researchers also determined that vanilla custard flavoring is the most toxic of the varieties tested.
“This experiment told us that the flavoring chemicals added to vaping devices can increase harm beyond what the nicotine alone can do,” Dr. Noujaim says.
Vaping flavors make you lose your rhythm
The study also tested flavored vaping’s impact on live mice. Researchers implanted each subject with a tiny electrocardiogram device before exposing them to 60 puffs of vanilla-flavored e-vapor five days a week for 10 weeks.
Study authors looked at how this exposure impacted heart rate variability (HRV), which is the change in time intervals between successive heartbeats. The results show that HRV decreased in vaping mice compared to those only exposed to puffs of clean air.
The USF team finds vaping interferes with normal HRV by disrupting the autonomic nervous system and its control over heart rate. Mice exposed to flavored vaping are also more prone to a dangerous heart rhythm problem called ventricular tachycardia.
Researchers say they still have to confirm these results in humans. Dr. Noujaim urges policymakers to continue looking at the growing evidence that vaping is not a particularly safer alternative to smoking.
“Our research matters because regulation of the vaping industry is a work in progress,” Dr. Noujaim explains. “The FDA needs input from the scientific community about all the possible risks of vaping in order to effectively regulate electronic nicotine delivery systems and protect the public’s health. At USF Health, in particular, we will continue to examine how vaping may adversely affect cardiac health.”
The study appears in the American Journal of Physiology- Heart and Circulatory Physiology.