High Times on Death Sticks: Is Cannabis Smoking as Harmful as Cigarette Smoking?

In recent years, many researchers have sought to determine whether smoking marijuana is as harmful as smoking tobacco cigarettes. Health authorities such as the American Lung Association are concerned about the health impacts of weed usage, particularly on the lungs.

While there are several ways to consume marijuana, smoking remains among the most popular. It seems obvious that inhaling combusted plant matter could lead to adverse health effects. However, the extent of this damage is the main point of contention.

This article investigates the harms associated with marijuana smoking, specifically the effects of this practice on the respiratory system. It also looks into whether there is a link between smoking marijuana and an elevated risk of cancer.

Key Points

Marijuana & Respiratory Problems

A 1993 article published in The Western Journal of Medicine discovered that regular marijuana users had more outpatient medical visits for respiratory problems than non-smokers. Other research suggests that smoking weed can reduce the respiratory system’s immune response. Consequently, regular users are more likely to suffer from respiratory infections such as pneumonia.

Furthermore, marijuana smoking is linked with increased airway resistance, lung hyperinflation, and large airway inflammation. A 2013 study by Tashkin stated that regular marijuana smoking by itself results in microscopic and visible injury associated with an increased likelihood of chronic bronchitis.

A study published in the popular journal, Addiction in 2021 noted that smoking cannabis might lead to the development of severe bronchitis, even at low exposure. The study also suggests that marijuana use is associated with a change in lung function over time. However, the authors said there is still “no convincing evidence that this leads to chronic obstructive pulmonary disease.”

A 2016 study  also analyzed the damaging effects of marijuana use on the lungs. According to the researchers, cannabis smoke affects the lungs similarly to tobacco smoke, leading to symptoms such as sputum and cough. Similar to the Addiction study, the researchers asserted that smoking cannabis is linked with chronic bronchitis symptoms.

Marijuana & Lung Damage

In 2012, one of the most comprehensive studies of its kind compared the effects of smoked marijuana with smoked tobacco on pulmonary function. Led by the University of California, San Francisco (UCSF) and the University of Alabama at Birmingham, the study analyzed data from over 5,000 American adults across 20 years.

According to Mark Pletcher of UCSF, the research team discovered what they expected with tobacco exposure. That is, a “consistent loss of lung function with increasing exposure.” However, Pletcher explained the researchers were “surprised that we found such a different pattern of association with marijuana exposure.”

The researchers measured the following metrics from the 5,115 volunteers:

The team used a spirometer (which measures airflow when the user breathes in and out) to measure lung function.

They found that, overall, the more tobacco you use, the more issues you have with lung volume and airflow rate. Among marijuana users, the airflow rate increased with a greater level of consumption to a certain point.

It Isn’t All Good News

It is incorrect to say that smoking marijuana is definitely less harmful to your lungs than smoking tobacco. According to Pletcher, a lot depends on exposure to each substance. On average, you will smoke more cigarettes than joints. For instance, most weed users will seldom smoke more than a handful of joints a day. In contrast, tobacco users may smoke 20+ cigarettes daily.

Therefore, a cigarette smoker’s overall exposure to the harmful components of combusted tobacco is likely significantly greater than a weed smoker’s exposure to combusted marijuana.

The researchers in the study could not find many examples of extremely heavy marijuana exposure. Consequently, all they can say is that occasional marijuana exposure is less harmful to the lungs than regular tobacco exposure.

A study published in 2022 followed the marijuana usage of over 1,000 adults from Dunedin in New Zealand. The researchers analyzed the volunteers for 27 years, asking them to report their cannabis and tobacco usage at six specific age intervals.

Ultimately, those who used cannabis regularly had over-inflated lungs. Also, weed usage amongst such individuals resulted in a greater degree of airflow resistance than tobacco users. While the findings showed that marijuana smoking isn’t good for the lungs, the researchers admitted they didn’t completely understand the long-term health and wellbeing consequences.

Marijuana & Cancer Risk

The link between tobacco smoking and cancer is so obvious it seems incredible that anyone ever thought otherwise! In 1964, Surgeon General Luther Terry famously released the United States Surgeon General’s first Smoking and Health report. The report also involved the assistance of an advisory committee.

After consulting over 7,000 articles on cigarette smoking, the committee concluded that smoking was a probable cause of lung cancer in men and women, a cause of laryngeal cancer in men, and the most important cause of chronic bronchitis. Indeed, scientists have known about the link between cigarettes and lung cancer since at least the 1940s.

We know that cigarette smoke contains over 7,000 chemicals, and at least 69 are carcinogenic. Data from the CDC suggests that up to 40% of cancers diagnosed in the United States have a potential link to tobacco use. There is little more we need to add: Smoking tobacco cigarettes seriously increases your risk of developing cancer!

However, are you just as likely to develop cancer if you’re a regular marijuana smoker?

What Does the Research Say?

Researchers can’t determine the extent to which marijuana smokers increase their risk of cancer. Indeed, even though the practice damages the lungs, it doesn’t necessarily enhance your overall cancer risk.

A study published in Cancer Causes & Control in 2013 looked into marijuana use and the risk of lung cancer. The researchers examined men aged 18-20 while on mandatory military duty in Sweden in 1969-70. They tracked the males until 2009 and analyzed the data they found regarding lung cancer outcomes.

The researchers discovered that heavy cannabis smokers, which meant people who smoked it 50+ times during their lifetimes, were twice as likely to develop lung cancer as the national average. The team also accounted for alcohol use, socioeconomic status, and baseline tobacco use.

The 2013 Tashkin study looked at the effects of weed smoking on the lung. It pointed out that marijuana smoke contains carcinogens, which can cause cancer. However, Tashkin also said there was no evidence that light or moderate weed-smoking results in an elevated lung or upper airway cancer risk.

The Jury Is Out

Data from a study published by Tashkin in 2006 found no link between cannabis use and lung cancer. This was true even among heavy cannabis users – including individuals who “smoked more than 20,000 joints in their life.”

The 2021 study in Addiction in 2021 cites a similar relationship regarding the effects of marijuana vs. tobacco on lung health. The researchers said that “an association between cannabis and lung cancer [still] remains unproven,” though studies continue to produce conflicting findings.

Meanwhile, a 2017 report published by the National Academies of Sciences, Engineering, and Medicine found no statistical association between weed smoking and neck, head, and lung cancers. Furthermore, the report found limited or no evidence relating to any links between marijuana smoking and a variety of cancers, including:

The consensus is that marijuana may increase your risk of cancer compared to non-smokers. After all, weed smoke contains carcinogenic combustion products such as benzanthracene and benzopyrene in greater quantities than tobacco smoke. Also, as marijuana smokers hold in the smoke for longer, the process quadruples the tar deposition compared to cigarette smoking.

However, a 2005 study published in Harm Reduction Journal found that cannabis and tobacco smoke are NOT equally carcinogenic. The study author, Robert Melamede, wrote that components of cannabis smoke minimize some carcinogenic pathways. In contrast, tobacco smoke enhances some.