A new study reports that a single exposure to e-cigarette (e-cig) vapor may be enough to impair vascular function, say researchers from West Virginia University. They presented their findings recently at theCardiovascular Aging: New Frontiers and Old Friendsseminar in Westminster, Colo.
The researchers studied artery diameter, the blood vessels ability to widen (vasodilation), and aortic stiffness in female mice after short and long-term exposure to flavored e-cig vapor. Aortic stiffness is an age-related complication in the hearts main artery (aorta) that can be an indicator of cardiovascular disease. They found that within an hour of the five-minute e-cig exposure, the short-term groups arteries narrowed by approximately 30 percent. Vasodilation decreased as well.
E-cigarettes are often perceived to be less harmful than their traditional counterparts, but they could still expose the people who "vape" and those around them to harmful compounds. Long-term exposure to e-cig vapor - 20 hours per week over a period of eight months - also produced negative effects of chronic e-cig use, including aortic stiffness, which was more than twice as high as control groups exposed to normal room air. These data indicate that e-cigs should not be considered safe and that they induce significant deleterious effects on blood vessel function, say the authors.
Just a few weeks ago, researchers reported in ACS' journalEnvironmental Science & Technologythat heavy use and secondhand emissions could lead to inhaled levels of toxins that exceed set exposure limits. But under typical use, secondhand exposure would have a lower impact on health than second and third-hand cigarette smoke.
While e-cigarettes don't produce tobacco smoke with its associated toxins, the vapors they generate contain other compounds that are potentially dangerous to human health. These include acrolein, a toxin and irritant to the eyes, skin and nasal passages; formaldehyde, which is recognized as a human carcinogen; and diacetyl, a substance that can cause respiratory problems. Hugo Destaillats and colleagues wanted to find out how much of these compounds users and others nearby might be inhaling.
Vapers' intake of toxic compounds was modeled for scenarios in which different e-liquids were used with various vaporizers, battery power settings and vaping regimes. The study predicted that heavy users inhaling at a high rate of 250 puffs per day with devices at 3.8 to 4.8 volts would potentially inhale levels of acrolein - up to 10 milligrams per day; formaldehyde - up to 49 milligrams per day - and diacetyl - up to 0.5 milligrams per day - that exceed U.S. occupational limits of 1.3 milligrams per day, 0.1 milligrams per day and 7 micograms per day, respectively.
A model of indoor exposure also estimated that in bars where vaping is permitted, formaldehyde and acrolein levels would often exceed California reference exposure limits. In comparison to secondhand and thirdhand tobacco smoke, the researchers computed that "disability-adjusted life years" lost due to exposure to secondhand vapor would be one to two orders of magnitude lower under typical vaping use.
Hazards Of Cigarette Smoking
In June, Wake Forest Medical Center issued a press release stating that cigarette smoking presents far more health hazards than most people probably realize inflicting damage throughout the body. The list of conditions that smoking can cause, contribute to, increase the risk of or worsen runs from high blood pressure, type 2 diabetes and stroke to gum disease, arthritis and erectile dysfunction. Cigarette smoke does such diverse harm because it contains somewhere between 4,000 and 9,000 different chemicals, hundreds of which are toxic, including around 70 known to be carcinogenic.
Some people are very health conscious even though they smoke and know a lot about the various problems associated with smoking, said John Spangler, M.D., professor of family and community medicine at Wake Forest Baptist Medical Center and a recognized expert in tobacco use and smoking cessation. But other people arent as informed, so, overall, the less publicized, more unusual effects of smoking are not well known. When you smoke, these various chemicals get into the bloodstream, are carried to all parts of the body and go right to the most susceptible cells. Thats why theres such a wide array of negative effects from cigarettes.
One of the main culprits is carbon monoxide, the gas produced by the incomplete burning of any material containing carbon. It reduces the ability of red blood cells to carry essential oxygen to tissues in the brain, heart and other parts of the body, which can result in problems ranging from shortness of breath to heart failure. Most of the other malevolent agents are the chemicals found in tar, the resinous matter generated by burning tobacco that builds up in the lungs.
The effects of these chemicals include inflaming the linings of blood vessels and other soft tissues, reducing the bodys ability to fight infections, slowing the healing process and causing the release of free radicals, unstable molecules that react with other molecules and produce different disorders, including cancer, in different types of cells throughout the body. There are also cancer-specific compounds in tar that directly damage cell DNA and generate tumors in the lungs and other organs, such as the pancreas, kidneys and liver.
What About Nicotine?
Surprisingly, tobaccos best known component nicotine is not among its most lethal. The nicotine in cigarette smoke activates the brain circuits that regulate feelings of pleasure in the same way as other drugs, such as heroin. Nicotine levels peak within 10 seconds of inhalation but dissipate quickly, as do the associated feelings of reward, which causes the smoker to continue smoking to maintain the drugs pleasurable effects and prevent withdrawal.
Nicotine doesnt cause the cancer or the emphysema, Spangler said. It causes the addiction. Nicotine isnt totally harmless. It increases your blood pressure a little bit, for example, but its side effects are relatively minor and its generally regarded safe enough that the FDA allows it to be sold over the counter as a smoking-cessation aid. Even if you dont inhale, the chemicals get into your body through your mouth, plus the second-hand smoke through your nose. And water pipes are not safer at all. The water cools the smoke so it doesnt feel as irritating, but thats all it does. The vast majority of the harmful chemicals are still in there. And theres an incredible amount of second-hand smoke exposure with hookahs.
Long-Term Health Risks
Research has shown that all cigarettes pose the same high level of health risks, including those marketed as low-yield, natural or additive-free. Other modes of smoking tobacco - cigars, pipes, hookahs - also present serious health hazards. E-cigarettes and other electronic nicotine delivery systems (ENDS) produce vapor, not smoke, through the heating of nicotine-infused liquid, sometimes with flavoring added.
The liquid in e-cigarettes is generally regarded as safe, Spangler said. There are long-term health concerns, and we dont yet know what those may be, but we do believe that in the short term using e-cigarettes is safer than continued cigarette smoking. However, he noted, the contents of the liquid, flavorings and heating elements in ENDS have not been closely regulated, and examples of all three have been found to contain hazardous elements. And the batteries of some electronic cigarettes have exploded, causing severe burns.
Quitting smoking is clearly the best way to avoid health risks. And it can have almost immediate benefits. The risk of heart attack, for example, begins to decrease within 48 hours of stopping to smoke.
E-Cigs Helping Americans Quit Smoking In Higher Numbers
University of California San Diego School of Medicine and Moores Cancer Center researchers recently performed a population-level analysis of national surveys conducted from 2001 to 2015 and found that in the United States the smoking cessation rate increased for the first time in 15 years. The study suggests e-cigarettes helped users of the electronic devices to quit smoking traditional cigarettes.
The annual rate of people who quit smoking has hovered around 4.5 percent for years but in the 2014-15 Current Population Survey-Tobacco Use Supplement (CPS-TUS) survey the smoking cessation rate increased to 5.6. The 1.1 percentage point increase is statistically significant, representing approximately 350,000 additional smokers who quit in a 12-month period.
Shu-Hong Zhu, PhD, UC San Diego professor of Family Medicine and Public Health and director of the Center for Research and Intervention in Tobacco Control, and team published their findings in theBritish Medical Journalon July 26, 2017. Zhu attributes the increased cessation rate, in part, to national tobacco control media campaigns that began airing in 2012 and an increase in the popularity of e-cigarettes that spiked around 2014.
Our analysis of the population survey data indicated that smokers who also used e-cigarettes were more likely to attempt to quit smoking, and more likely to succeed, said Zhu. Use of e-cigarettes was associated both with a higher quit rate for individuals as well as at the population level; driving an increase in the overall number of people quitting.
Link Between E-Cigs And Smoking Cessation
Zhu and team examined the relationship between e-cigarette use and smoking cessation using data collected by the US Census CPS-TUS, a national survey of adults 18 years or older conducted to obtain information about changes in the countrys use of tobacco products. It is based on the largest representative sample of smokers and e-cigarette users available, although it is not a randomized trial.
Survey participants were asked about their use of traditional cigarettes and e-cigarettes over a 12-month period. Researchers found that 65 percent of smokers who used e-cigarettes within the previous 12 months had attempted to quit smoking traditional cigarettes, compared to 40 percent of smokers who did not use e-cigarettes. Overall, 8.2 percent of smokers who used e-cigarettes successfully quit smoking traditional cigarettes, while 4.8 percent of smokers who did not use e-cigarettes were successful.
The cessation rate among those who did not use e-cigarettes remained the same compared to previous years, said Zhu. These data suggest that e-cigarettes play the role of a cessation tool.
Earlier studies have also looked at e-cigarettes as a cessation tool, and some have concluded that e-cigarette use did not aid smokers in quitting. A key finding in this analysis, said Zhu, is that in 2014-15 more people using e-cigarettes were doing so intensively. In fact, more than 70 percent of people who had successfully quit smoking recently were still using e-cigarettes daily, which may help prevent relapse, wrote researchers.
People who use e-cigarettes are a self-selected group, said Zhu. They may do better with e-cigarettes because they may already be motivated to quit. It is important to look at the entire population including users and nonusers to determine if the overall cessation rate went up or down.
This study did not address the long-term health effects of e-cigarette use. Rather, the study focused on whether e-cigarettes contributed to peoples ability to quit smoking. The survey did not provide details about the type of e-cigarettes used nor if other smoking cessation tools, such as medications or pharmacotherapy, were simultaneously used. Clinical trials have shown that pharmacotherapy does help some individuals to quit smoking. However, in the years before e-cigarette use became widespread, the rates of smoking cessation among the entire population did not change significantly despite the promotion of pharmacotherapy, according to Zhu.
This study did not investigate if the use of e-cigarettes leads people to start smoking. However, theCenters for Disease Control and Prevention reportrecently reported that tobacco use among youth continues to decline rapidly while e-cigarette use increased during the same time period. The UC San Diego study focused on adults. It revealed that most e-cigarette users were already smoking cigarettes. Two percent of people who reported that they have never smoked cigarettes have tried e-cigarettes at some point.
Other interventions that occurred concurrently, such as a national campaign showing evocative ads that highlight the serious health consequences of tobacco use and state tobacco control efforts, no doubt played a role, said Zhu. But analysis of the CPS-TUS most recent data presents a strong case that e-cigarette use contributed to an increase in smoking cessation at the population level.