More Americans are kicking the cigarette habit each year.

Meanwhile, marijuana use is at an all-time high. Recent research indicates that 1 in 4 adults now use cannabis at least occasionally, and that smoking was their favorite means of consumption.

There are several factors behind this cultural shift from tobacco to pot. Decades anti-smoking campaigns of research and into the harms of cigarettes certainly played a part. We’ve come a long way from 19th-century beliefs that tobacco provided medical benefits, and from the mid-20th-century commercials proclaiming, “More doctors smoke Camels than any other cigarette!”

At the same time, attitudes toward marijuana have mellowed and increasing legality has facilitated risk-free purchasing and consumption of cannabis products. A third factor may be marijuana’s reputation for providing medicinal benefits, strengthening its reputation as a therapeutic agent rather than a health-compromising vice.

A growing number of cannabis consumers believe that smoking marijuana poses fewer risks than smoking tobacco. A four-year internet survey of marijuana-using adults found that:

• People increasingly felt that exposure to cannabis smoke was safer than tobacco smoke.
• In 2017, 26% of people thought that it was safer to smoke a cannabis joint than a cigarette daily.
• In 2021, over 44% chose cannabis as the safer option.

Research from the University of Texas at Austin published in 2024 showed that 50% of all cannabis users surveyed felt there was no risk associated with smoking marijuana one or two times per week, while another 46% thought there was a slight to moderate risk.

But, is perception reality? Responsible cannabis user owe it to themselves compare the potential risks of smoking marijuana as compared to cigarettes, based on all available information.

So, what do we actually know about cigarette and marijuana smoke? The Center for Disease Control identifies smoking tobacco as the world’s leading cause of preventable death, responsible for almost a half million deaths a year in the United States alone. Enough said, and no need to go into more detail on a subject that’s been thoroughly covered for decades.

But while the case against cigarette smoke is cut and dried, there are still questions to be answered about the safety of smoking marijuana. For decades, answering these questions was hindered by numerous factors. Fewer long-term, large-scale studies on smoking marijuana exist due to historic regulatory challenges. Illegality limited laboratory research and required studies to draw conclusions based on indirect and sometimes imprecise user-supplied information. In addition, a significant number of cannabis users are also tobacco smokers, which further blurs comparisons.

That said, currently available research literature does provide some answers into the nature of cannabis smoke and it’s risk profile.

What’s in the Smoke?

There’s nothing good about tobacco smoke. It contains a witch’s brew of heavy metals and volatile compounds, including benzene, cadmium, formaldehyde hydrazine, lead, nickel and traces of uranium-235 and polonium-210. And then there’s a list of 600-plus additives that are mixed and matched into commercial cigarettes.

Cigarette and marijuana smoke have things in common, but they are not the same. A comprehensive comparison published in Scientific Reports identified 4,350 different compounds in tobacco smoke and 2,575 different compounds in marijuana smoke, but found only 231 in common. Analysis showed that:

• Tobacco smoke contained 173 compounds known to cause negative health effects, while marijuana smoke tallied 110.
• Particles from an unfiltered marijuana joint measure about 30% larger than those from a filtered cigarette.
• The total particulate matter in tobacco smoke and marijuana smoke is similar.

In 2005, the Harm Reduction Journal published a study from the University of Colorado titled “Cannabis and tobacco smoke are not equally carcinogenic.” The authors explained that:

Both [tobacco and marijuana] smoke contain carcinogens and particulate matter that promote inflammatory immune responses that may enhance the carcinogenic effects of the smoke. However, cannabis typically down-regulates immunologically-generated free radical production by promoting a Th2 immune cytokine profile.

Furthermore, THC inhibits the enzyme necessary to activate some of the carcinogens found in smoke. In contrast, tobacco smoke increases the likelihood of carcinogenesis by overcoming normal cellular checkpoint protective mechanisms through the activity of respiratory epithelial cell nicotine receptors.

More recently, a study published by the Lancet’s eClinicalMedicine group compared marijuana-only smokers, tobacco-only smokers, and dual marijuana-tobacco smokers. The authors reported that all three groups had smoke-related toxic chemicals in their blood and urine, but that levels of these toxins were significantly lower in the marijuana-only participants.

There may also be significant differences in the composition of smoke from different varieties of marijuana. When researchers in New Zealand analyzed the smoke of 40 different marijuana samples, they found significantly different levels of particulate matter between samples. They also noted that the major variable in the composition of the smoke was the terpene content, with a 40-fold difference between the lowest and the highest levels. As CannaMD has reported, terpenes are believed to enhance the healing effects of cannabis.

Another variable is the source of marijuana being consumed. There can be substantial differences in purity between black market products containing dangerous additives such as vitamin E acetate and medical marijuana that is tested and third-party regulated. Buying from known and safer sources may account for the conclusions from a University of Indiana study showing that vaping-related respiratory illnesses decrease in areas where marijuana is legally available.

Smoking & Lung Health

First, a quick review: some 85% of lung cancer is caused by smoking tobacco. Smoking less can lower the risk significantly, but quitting smoking remains the safest choice.

Second, a warning for anyone using both tobacco and cannabis. Research from Dalhousie University indicates that “People who smoke both cigarettes and marijuana are 12 times more likely to develop harmful lung conditions.”

With those statements out of the way, it’s time to focus on marijuana-only smokers. CannaMD has reported on the question “Does Smoking Marijuana Cause Lung Cancer?” Key points of that reporting include:

• A large-scale study by Kaiser Permanente concluded that marijuana use was not associated with tobacco-related cancers or lung cancers.
• Research from France found little to no evidence that marijuana use, independent of tobacco use, was associated with an increased risk of lung cancer.
• A review of 19 lung cancer studies conducted by Case Western Reserve University “failed to demonstrate significant associations between marijuana smoking and lung cancer after adjusting for tobacco use.”

A 2018 review from Imperial College London states that:

There is currently no clear association between cannabis smoking and lung cancer, although the research is currently limited. We do not know why cannabis smoking does not appear to be carcinogenic. Various factors [that might contribute to this phenomenon] include the potential anti-inflammatory and anti-neoplastic properties of THC and other cannabinoids.

The Dana-Farber Cancer Institute found that while smoke-related toxic chemicals were found in the blood and urine samples of both tobacco and marijuana smokers, levels were significantly lower among marijuana-only smokers. The most newsworthy finding from the study was that levels of the chemical acrolein were elevated in cigarette smokers, but not in marijuana smokers.

Research from Poland’s University of Lodz implicates acrolein as “a major culprit in lung diseases and respiratory cancers.” The authors write that:

Acrolein is considered one of cigarette smoke’s most toxic and harmful components. Chronic exposure to acrolein through cigarette smoke has been linked to the development of asthma, acute lung injury, chronic obstructive pulmonary disease (COPD) and even respiratory cancers.

A 20-year study of 5,000 cannabis users published in the Journal of the American Medical Association concluded that occasional and low cumulative marijuana use was not associated with adverse effects on pulmonary function.

The same research noted an unexpected effect of smoking cannabis. Two measures of lung function that measure the lung capacity and ease of exhalation increased with low to moderate marijuana use.

Harvard Health offers a potential explanation for this phenomenon, writing that:

The way pot is smoked may be the reason marijuana could have some pulmonary benefits. The deep, sucking inhalation may stretch lung tissue to expand lung volume. It may also strengthen the muscles of the chest wall, enabling pot users to inhale and exhale air more forcefully.

Cannabis & COPD Risks

Chronic obstructive pulmonary disease (COPD) is a debilitating and sometimes fatal disease caused by air pollution or long-term smoke inhalation. Around 14 million Americans suffer from the restricted breathing, fatigue, wheezing and phlegm-clogged lungs caused by COPD. World Health Organization data shows that while air pollution is the major cause of COPD worldwide, in high-income countries like the United States, smoking tobacco accounts for 70% of all cases.

A report from the Global Initiative for Chronic Obstructive Lung Disease proposed quitting cigarette smoking as an important step in preventing and treating COPD. Similarly, a systematic review of literature from Shandong University stated that quitting smoking was the single most effective way to reduce the risk of developing or worsening COPD.

A research study of Canadian cigarette and marijuana smokers reported that:

• Compared with nonsmokers, participants who reported smoking only tobacco, but not those who reported smoking only marijuana, experienced more frequent respiratory symptoms.
• Smoking only marijuana was not associated with an increased risk of respiratory symptoms or COPD.
• Smoking both tobacco and marijuana synergistically increased the risk of respiratory symptoms and COPD.

The authors summarized their findings with the explanation that:

Our study had insufficient power to detect a modest association between smoking only marijuana and increased risk of COPD. However, we were able to detect a significant synergistic effect between marijuana smoking and tobacco smoking. This effect suggests that smoking marijuana (at least in relatively low doses) may act as a primer, or sensitizer, in the airways to amplify the adverse effects of tobacco on respiratory health.

More recently, a 2025 survey of of some 380,000 cannabis users mentioned:

An elevated odds of COPD with inhaled cannabis use among adults of all ages and those younger than 50 years.

While qualifying that statement by adding that:

These associations were less precise when we restricted to those with no lifetime tobacco cigarette use, with a non-significant elevated odds of disease among those with no lifetime tobacco cigarette use.

The authors concluded by clarifying that a lack of statistical significance is not the same as having no effect. They stated that “these results do not provide reassurance that inhaled cannabis is safe with respect to COPD.”

Smoking’s Effect on Weight, Metabolic Function, & Diabetes Risk

Cigarette and marijuana smokers have something in common: both groups tend to weigh in a bit lighter than the general population. The nicotine content of tobacco provides a limited degree of metabolic boost, but the real weight savings appear to come not from burning more calories, but from tobacco’s appetite-suppressing effects.

Unfortunately, nicotine-induced dieting has its downsides. Tobacco can decrease appetite, but there are indications that it may also create a preference for high-calorie, low-nutrient foods. More troubling are the findings of a recent study from the University of Copenhagen. The study’s lead author explains that:

Starting to smoke and smoking over a lifetime might cause an increase in belly fat. The type of fat that increases is more likely the visceral fat, rather than the fat just under the skin.

Deep visceral fat lines the body’s inner abdominal wall and surrounds internal organs. It is considered an unhealthy fat linked to increased risks of diabetes, heart disease, and stroke.

More bad news for smokers comes from a 2024 study from India showing that cigarette smoking was associated with a 3.6 times greater odds of developing Type 2 diabetes. And from the American Journal of Clinical Nutrition, which reported that:

The chemicals in cigarette smoke cause inflammation throughout the body, which may decrease the effectiveness of insulin. Cigarette smoke can also cause oxidative stress, resulting in cell damage. Both oxidative stress and inflammation may cause an increased risk of diabetes.

Cannabis users as a whole have lower body mass indexes than the general population. But unlike tobacco, which suppresses appetite, marijuana is well-known for the appetite-boosting effect known as “the munchies.” The American Journal of Epidemiology reports that:

Despite the evidence that cannabis use stimulates appetite in clinical trials and laboratory studies, cannabis users are actually less likely to be obese than nonusers.

Other interesting takeaways from studies reported by CannaMD include the findings that:

• Obesity rates declined the most among frequent cannabis users.
• Frequent marijuana users ate more but maintained a lower average body mass index
• Marijuana users didn’t exhibit elevated lipid and glucose levels

A 2012 survey based on data from the National Health and Nutrition Examination Survey found that marijuana users have an overall lower rate of diabetes that the general population. This phenomenon was also noted in a large-scale Swedish survey of men and women ages 18 to 84. The authors wrote that:

The present study suggests that there is no association between cannabis use and subsequent type 2 diabetes after controlling for age.

Smoking & Inflammation

Chronic inflammation can increase the risk of circulatory problems and heart diseases, including atherosclerosis, heart attacks, and strokes. Tobacco contains a range of chemicals that can trigger inflammation. Research shows smoking tobacco increases pro-inflammatory biomarkers such as C-reactive protein (CRP). Chronically elevated CRP levels are considered a risk factor for heart attack and stroke.

Unlike tobacco, which has inflammatory effects, marijuana is known to help control and alleviate inflammation. A recent study from the University of Colorado Boulder found that cannabis use controlled key inflammatory agents and reduced peripheral inflammation (inflammation that occurs outside the central nervous system). The research also found that cannabis moderated insulin sensitivity. Elevated insulin sensitivity is associated with a greater risk for developing type 2 diabetes.

An Israeli study published in Frontiers in Pharmacology confirmed that phytocannabinoids, including THC, CBD and CBG, have significant anti-inflammatory properties, and that these inflammation-fighting effects became stronger when multiple cannabinoids were in the mix. The authors wrote that

Cannabis compounds were shown to affect some of the cornerstones of chronic inflammation.

Smoking & Mortality

Study after study says the same thing: smoking tobacco can take years off your life and degrade the quality of life in later years. It’s also proven that cutting back on cigarettes or quitting can add some of those years back, but smokers as a whole still die younger than non smokers.

Based on currently available information, there has never been a death directly attributable to smoking pure marijuana. The important word here is pure, because deaths have been linked to smoking black-market products, including vapes, synthetic cannabis, and marijuana laced with other drugs. Consumers can avoid these risks by sticking to legally-sourced cannabis products with a known and certified content.

Do You Have Questions About Medical Marijuana?

CannaMD‘s state-certified network of medical marijuana doctors is available to provide advice and assistance with your medical marijuana questions and needs. Contact CannaMD‘s experienced team at (855) 420-9170 today. Ready to get your card and purchase legal cannabis products? You can find out if you qualify for medical marijuana treatment with our quick online application.