Vaping vs Smoking: Weighing the Evidence

All the known dangers and potential risks of vaping and smoking in one place.


Updated on June 21, 2018

Every discussion of vaping should include a comparison with smoking. That’s because most vapers were smokers, and if not for vaping, most vapers would still be smokers. On top of that, if vaping survives the huge challenges to its very existence, millions of would-be smokers will be btter off being diverted from cigarette addiction by low-risk nicotine alternatives like e-cigarettes.

But when it comes to actual science, far too few studies employ a direct comparison between vaping and smoking. That’s probably because studies are done largely by people in the tobacco control field, and most of them want to see total elimination of all nicotine use.

So if a paper compares, say, carcinogenic compounds in smoking vs vapor, the results will show that smoke contains vastly larger quantities of the things that cause cancer. And pointing that out doesn’t serve the cause of abstinence very well. However, comparing vapor to clean air makes vapor look bad.

Vaping vs smoking: health effects

Vaping is 95% less harmful than smoking-Infographic

More than sixty years of science has proven that smoking is a very risky activity. Around half of all long-term smokers will die prematurely from its effects. The science on vaping is much newer, but what we do know is that no serious or widespread harms have been proven.

According to the 2014 Surgeon General’s report on smoking, about 16 million Americans suffer from some smoking-related disease, with 480,000 of them dying each year. Let’s look at the major categories of health problems caused by smoking and see if vaping poses risks in the same areas.



Cancers form when toxins damage or mutate a cell’s DNA and cause it to grow out of control. A tumor can remain local, or the cancer can spread, and even move from one organ to another.

Most people are familiar with cigarette smoking as a cause of lung cancer. Lung cancer kills more Americans than any kind of cancer, and most (but not all) lung cancer victims are smokers. It is a particularly brutal form of cancer.

However, smoking can cause many other kinds of cancer too, because cancers can form not just in areas that have contact with the smoke, but also from smoke byproducts in the bloodstream and organs. According to the Centers for Disease Control and Prevention (CDC), smoking can cause cancer almost anywhere in the body.

Some of the cancers that can be caused by smoking are:

  • Blood (leukemia)
  • Bladder
  • Cervix
  • Colon and rectum
  • Esophagus and trachea
  • Kidney and renal pelvis
  • Larynx
  • Liver
  • Lungs
  • Mouth and throat
  • Pancreas
  • Stomach

Nicotine itself — either in cigarettes or e-cigs, or other nicotine products — has not been shown to cause cancer. Long-term studies of nicotine replacement therapy (NRT) and Swedish snus users show no provable link between nicotine and cancer.

The 2016 Royal College of Physicians (RCP) report “Nicotine Without Smoke” says that “robust evidence on the safety of long-term nicotine use in humans from the 5-year Lung Health Study, in which participants were actively encouraged to use NRT for several months and many continued to consume NRT for a much longer period, demonstrates no association between sustained NRT use and the occurrence of cancer (lung, gastrointestinal or any cancer) or cardiovascular disease.”

Cancers from smoking are caused by the combustion of tobacco. The smoke forms a sticky chemical slurry called tar, and the tar coats delicate parts of the lungs. Over the course of years, the damage created by tar in the lungs can lead to tumor growth. According to the National Cancer Institute (NCI), most of the cancer-causing substances in cigarette smoke are in the tar. Tar also causes damage that can lead to lung diseases like emphysema and bronchitis.

“This study should put to rest any doubt within the tobacco control movement about whether vaping greatly reduces health risk compared to smoking.”

E-cigarettes don’t produce tar, because they don’t burn (or even contain) tobacco or other plant material. There are known carcinogens in vapor, but they’re in tiny concentrations that are unlikely to pose any risk to vapers. Most studies that have raised alarms about cancer risk from vaping have used poor methods, including using smoking machines to take too-frequent or too-long drags, or vaping at unrealistic high temperatures on dry wicks. Those things wouldn’t happen to actual vapers, because the result — known as dry hits or dry puffs — is unbearable to breathe.

“In normal conditions of use, toxin levels in inhaled e-cigarette vapour are probably well below prescribed threshold limit values for occupational exposure, in which case significant long-term harm is unlikely,” says the RCP report. “Some harm from sustained exposure to low levels of toxins over many years may yet emerge, but the magnitude of these risks relative to those of sustained tobacco smoking is likely to be small.”

A recent study at the University of St. Andrews in Scotland found that the cancer danger of vaping is almost as low as for nicotine replacement therapies like patches and gum — less than one percent. “This study should put to rest any doubt within the tobacco control movement about whether vaping greatly reduces health risk compared to smoking,” wrote Boston University’s Dr. Michael Siegel.

Heart disease and stroke


Smoking cigarettes causes about a third of all the heart disease deaths in the United States every year, according to the Surgeon General. Those deaths come in the form of heart attacks, heart failure, stroke, aneurisms, sudden cardiac arrest, and several other kinds of cardiovascular events that can be caused by conditions in the body that are caused or made worse by smoking.

As with cancer, nicotine isn’t a primary cause of acute cardiovascular events. The Surgeon General’s 2014 report says that “international epidemiologic evidence, and data from clinical trials of nicotine patches, suggests that chemical components in smoke other than nicotine are more important in elevating the risk of death from MI [myocardial infarction — heart attacks] and stroke.”

However, if you’re already suffering from heart disease, it may be prudent to reduce your nicotine intake. Nicotine can cause short-term spikes in heart rate and blood pressure, and people with existing risk factors for acute coronary events may have some added danger from using nicotine.

Some of the dangerous compounds found in tobacco smoke are also found in vapor, but in much lower concentrations.

By and large, it’s the other things in smoke that cause heart disease and death. Oxidant chemicals, free radicals, particulates, and carbon monoxide all damage the heart and circulatory system in many ways, according to the CDC.

Smoking can raise triglycerides and lower the HDL (“good”) cholesterol, and increase the buildup of plaque (from fat, cholesterol, calcium and other substances) in blood vessels. It can also thicken and constrict the vessels, and damage the cells that line them. It reduces oxygen in the blood and makes it sticky and more prone to clot. And when blood clots, it can block the flow to the heart and brain, causing heart attacks and stroke.

Some of the dangerous compounds found in tobacco smoke are also found in vapor, but in much lower concentrations. And perhaps the most dangerous constituent of cigarette smoke with regard to cardiovascular health — carbon monoxide — is not found in e-cig vapor at all.

There has been no research to date showing any provable cardiovascular danger from vaping.

Fine and ultrafine particles in cigarette smoke are a danger to the cardiovascular system, so naturally some vape-hating researchers have made a point of repeating that there are also particles in e-cig vapor. Stanton Glantz, the longtime anti-smoking (and now anti-vaping) activist from the University of California-San Francisco, has been beating the drum for dangerous ultrafine particles in vapor for years now.

And it’s true that there are particles in e-cig vapor, but they’re liquid droplets, not solid combustion products like the particles in cigarette smoke or diesel exhaust. Now you’d think that Glantz, whose training is in mechanical engineering, would understand the difference between liquid and solid, but maybe not.

“This perhaps explains why he had to leave mechanical engineering (where not knowing the difference between liquids and solids can be rather disastrous) and go into anti-tobacco extremist activism (where it is not such a problem to not know… well, anything),” Carl Phillips wrote.

There has been no research to date showing any provable cardiovascular danger from vaping.

Lung diseases


The third major disease group that smokers face is, for many, the most frightening. Chronic Obstructive Pulmonary Disease (COPD) — which includes emphysema, chronic bronchitis, and non-reversible asthma — is a terrible thing to see. Victims may die gasping for air they’re unable to inhale because their lungs have stopped functioning.

Smoking damages the lungs in several ways that can lead to COPD, according to the CDC:

  • The airways and alveoli (tiny air sacs in the lungs) lose their ability to stretch and shrink
  • The walls between the alveoli are damaged and destroyed
  • The walls of the airways become swollen and inflamed
  • The airways produce too much mucus, which blocks air flow

The causes of the damage from smoke are particulates and gasses in the smoke. The lungs try to fight the invading combustion products by producing mucus, but in heavy smokers they’re overwhelmed by the quantity of smoke, and eventually the mucus itself causes congestion and damage.

COPD is progressive. In fact, it may continue to develop even after the smoker quits cigarettes. And though there is treatment for the symptoms, there is no cure for COPD — except a lung transplant.

There is no indication that vaping causes COPD or any of its associated disease group (emphysema, chronic bronchitis, or non-reversible asthma). In fact, some research indicates that “the emerging evidence that EC [e-cigarette] use can reverse harm from tobacco smoking should be taken into consideration by regulatory authorities seeking to adopt proportional measures for the e-vapor category.”

Some forms of asthma may be caused by smoking, and asthma is certainly made worse and flare-ups more common by smoking. That’s because smoking causes many of the same symptoms in the lungs that set the stage for asthma to flare.

There is no evidence that vaping causes or worsens asthma. But even better, a study by Dr. Riccardo Polosa found that vaping shows signs of harm reversal in asthma sufferers — even if they just reduce their smoking.

Popcorn lung (bronchiolitis obliterans)

Whether smoking or vaping have ever caused a case of popcorn lung is a troublesome question. The answer is probably no, because although millions of smokers (but no vapers that we know of) have died from lung obstruction, no smoker or vaper has ever been diagnosed with popcorn lung (which is scientifically known as bronchiolitis obliterans).

Every news story you see with a title like “Does vaping cause popcorn lung?” completely ignores the fact that cigarettes have much more of the flavoring chemicals that are the likely culprits in causing this horrific lung condition. But no one has found any dead smokers with popcorn lung.

On the other hand, the symptoms of bronchiolitis obliterans are almost identical to advanced COPD — and lots of smokers die with COPD. So there may be cases of BO slipping through, since rarely is a lung biopsy done on a smoker who’s died of apparent COPD.

There is zero evidence that vaping causes popcorn lung, and lots of reasons to doubt that it ever will. But it is a messy issue. If you’re interested in more detail, we’ve done a more in-depth look at the issue of popcorn lung.

Pregnancy and smoking (and vaping)


Smoking during pregnancy can cause tissue damage in the unborn child, according to the CDC. And because carbon monoxide in smoke reduces the amount of oxygen carried in the blood, it prevents the baby from getting enough, which may cause miscarriage.  

Smoking may also lead to premature delivery, stillbirth, low birth weight, ectopic pregnancy, and cleft lip in the child. It’s also thought to cause Sudden Infant Death Syndrome (SIDS).

Studies with NRT use among pregnant women have shown no harm to babies from using nicotine without smoking during pregnancy. It is therefore likely that no harm to children would occur from mothers vaping while pregnant.

In fact, Prof. Linda Bauld of Stirling University in the U.K. is working to encourage pregnant women to use e-cigarettes to replace cigarettes.. Her work group has produced a report advising midwives and health professionals to encourage pregnant smokers to switch completely to vaping.

It’s refreshing to see practical advice being given to pregnant smokers. While smokers in general are often treated with scorn and disgust, pregnant smokers suffer even more stigmatization. Prof. Bauld’s Smoking in Pregnancy Challenge Group is really doing true public health work.

Health effects from vaping


You’ve seen how vaping hasn’t been proven to cause any major health risks like smoking has. But does it cause any known problems? The answer is a resounding…sort of.

While vaping so far hasn’t been proven to cause any actual diseases or serious chronic conditions, it is known to have some annoying side effects. And while they’re not going to endanger your life, for some people they’re annoying enough that they don’t like vaping.

Because the primary substances that are used to make vaping e-liquid are humectants — they absorb moisture from whatever environment they inhabit — vaping can dry you out. So if you spend all day vaping, expect to feel some dehydration symptoms.

  • Dry skin
  • Dry mouth
  • Dry eyes
  • Scratchy or sore throat
  • Coughing
  • Headache
  • Nosebleed

Vapers need to drink a lot of fluids to stay hydrated. Smoking causes some dryness too — cigarette smoke isn’t exactly a moisturizer — but it doesn’t suck your body dry like vaping can.

Nicotine side effects
If you’re a smoker, you probably know what it feels like to smoke one too many cigarettes on a break. You can get a queasy, almost-dizzy sensation. That’s too much nicotine.

It’s the same with vaping. If you try a liquid at a higher strength than you’re used to, or an atomizer that delivers more vapor than you’re used to, you can get a range of effects from the increased nicotine.

  • Dizzy or lightheaded
  • Headache
  • Nausea
  • Cold sweats
  • Insomnia
  • Racing heart
  • Anxious or jittery
  • Ringing ears

They’re only dangerous if you don’t stop. But before they could cause any real harm, you’d probably get a much worse headache, or vomit. So stop before you get to that point. Don’t worry, you’ll want to.

Avoiding weight gain
Nicotine is known to be an appetite suppressant, and both smoking and vaping can help with weight loss or weight maintenance. In fact, for those smokers who worry about gaining weight when they quit, vaping may be just the ticket. There has already been some educated speculation on the idea of vaping as a weight gain prevention tool by academics, including Stirling University professor Linda Bauld.

Sensitivities and allergies
People have true allergies to propylene glycol (PG) and vegetable glycerin (VG) very, very rarely. Both products are found in a lot of foods, cosmetics, and other household items, so it would be highly unusual to have such an allergy and not realize it before starting to vape.

More likely is a sensitivity to one of those substances (probably PG). But because the symptoms of such a sensitivity are very close to dehydration, you may not be sure what you have. If it’s serious enough to pursue, a dermatologist can test for allergic reactions.

Allergies to flavorings can be more serious. Some e-liquid uses natural flavorings that have actual food like nuts as an ingredient. Some people can have life-threatening reactions to such flavorings.

Vapers with such allergies should be alert at all times for the possibility of suspicious contents, and ask questions of the vendor when in doubt. If they can’t give you a certain answer, stay away from that e-liquid.


Media attention to “poisonings” by e-liquid and vape products has been massive for the last few years. Of course, really the stories refer to calls to poison control centers, which don’t necessarily mean poisonings at all. But that’s a detail lost in most news stories.

At the peak of the vaping media scares, in 2014, there was a nationwide total of 4,024 vaping-related calls to poison control centers, according to the American Association of Poison Control Centers (AAPCC), which keeps a running tally by month of the numbers. Because, of course, “The experts at America’s poison centers continue to be concerned about exposures to e-cigarette devices and liquid nicotine, especially children’s exposures.”

The AAPCC tracks prescription opioid calls too. And so far this year, there are more of those each month than there were calls about e-cigs and juice in all of 2014, which was the busiest year for vaping calls. In fact, calls about vapor products have declined each year since 2014, and they’re on track this year to be even lower than last year.

Laundry pods, which toddlers try to eat because they look just like candy have been responsible for more than 10,000 poison control calls over each of the last four years, and they’re on track to beat last year’s number. What’s the real problem here?

Good luck even finding the data on calls regarding cigarettes. Once your poisonous product has been eaten by children for a century, they stop paying particular attention to it. But it certainly does happen.

A study in the journal Pediatrics (about e-cigarette “poisonings,” of course) noted that of the more than 29,000 calls to poison control centers regarding nicotine and tobacco product exposures among children younger than six-years-old between January 2012 and April 2016, cigarettes accounted for 60.1 percent. E-cigarettes were in third place at just 14.2 percent.

Vaping vs smoking: cost


When I started smoking in 1974, cigarettes cost about 40 cents a pack. They wouldn’t cost a lot more than that now if the state and federal governments didn’t tax them at an insane rate.

Nowadays, cigarettes cost between $5 and $15 a pack in the U.S. If you smoke a pack a day, that’s about $150-450 a month, or $1,800-5,400 a year. A 30-year smoker could have bought a really nice car, instead of a case of chronic bronchitis and a blocked coronary artery.

Health is probably the biggest reason people quit smoking and start vaping. Cost is almost certainly the second biggest reason.

A new vaper can get started for less than the cost of a carton of cigarettes. An inexpensive mod and tank, a package of coils, and some e-liquid is all it takes, and once you find stuff you like, you’re just replacing the coils and e-liquid.

Vaping is only as expensive as you make it.

It’s no exaggeration to say that a someone who uses a vape can get by with cheap e-liquid (or make their own e-liquid for almost nothing), could happily vape for less than $50 a month — maybe a lot less. Granted, there are vapers who spend more on vaping than they did smoking.

Some high-end vapers buy extremely expensive premium e-liquid and collect handmade mods carved from the skulls of tobacco controllers. Not really. That was a joke. But they do buy very expensive mods and juice. And some sub-ohm cloud fiends go through 10, 20, even 30 mL of e-liquid a day.

But those vapers aren’t typical. I smoked almost two packs a day of cigarettes. When I started vaping — and for a couple years after I started — I vaped about 3 mL of 18 mg/mL e-liquid a day. I could have gone on happily like that without spending more than $30 a month on the juice I liked. Vaping is only as expensive as you make it.

Vaping vs smoking: it may be the choice of your life

For many smokers, taking up vaping works immediately — whether coming from cigarettes, pipes, cigars, or even hookah. For others though, it can take months to finally say goodbye to combustion. And for some, it never happens.

Unlike 10 years ago, when vaping first hit U.S. shores, we now have an almost unlimited variety of vape products to choose from. You can choose how you want to inhale, you can decide what exact level of nicotine you want to choose, you can carry a tiny pod device or a huge mod that delivers 200 watts of power.

If you’re a smoker who wants to quit, there are options that will work for you — if you choose to make some effort to find them. But there’s no longer a reason to say that “vaping doesn’t work.” Because it really can. And there’s no question now about whether vaping is safer than smoking.

You’ve seen all the comparisons. You know what smoking can do to you. You know what it costs.

What are you going to do now?

Jim McDonald
Smokers created vaping without any help from the tobacco industry or anti-smoking crusaders, and vapers have the right to keep innovating to help themselves. My goal is to provide clear, honest information about the challenges vaping faces from lawmakers, regulators, and brokers of disinformation. I recently joined the CASAA board, but my opinions aren’t necessarily CASAA’s, and vice versa. You can find me on Twitter @whycherrywhy