As cannabis becomes more widely used around the world, scientists are paying closer attention to how it affects human health.
A new long-term study from researchers at the University of Otago in New Zealand suggests that smoking cannabis can harm the lungs in ways that are different from tobacco smoking.
Both substances can damage the lungs, but the study found that they do not affect the body in exactly the same way. The researchers say their findings are important because many people believe cannabis smoke is less harmful than tobacco smoke.
The research was led by Professor Bob Hancox and used information from the well-known Dunedin Multidisciplinary Health and Development Study.
This long-running project has followed the lives and health of more than 1,000 people who were born in Dunedin, New Zealand, in 1972 and 1973. The participants have been regularly studied from childhood through adulthood, allowing scientists to understand how different lifestyle choices affect long-term health.
For this research, the scientists analyzed lung function in the participants up to the age of 45. Because the study tracked people for decades, it provides one of the most detailed pictures available of how cannabis use may affect lung health over time.
The researchers found that around 75 percent of the participants had used cannabis at least once in their lives. This shows how common cannabis use has become.
However, scientific research on the long-term effects of cannabis has historically been limited. One reason for this is that cannabis has been illegal in many countries for many years, which made it harder for scientists to study.
The study discovered that people who used cannabis heavily over many years often developed lungs that were more inflated than normal. Over-inflated lungs can make breathing less efficient because air becomes trapped inside the lungs.
The researchers also found that cannabis smokers had higher resistance to airflow, meaning air does not move through the lungs as easily as it should.
Interestingly, the researchers found that these effects appeared to be stronger in cannabis smokers than in tobacco smokers.
Another important finding was that cannabis smoking reduced the lungs’ ability to absorb oxygen. Oxygen is essential for the body because it allows organs, muscles, and the brain to function properly. In the past, this problem was mainly associated with tobacco smoking, but the new study shows that cannabis can also reduce oxygen absorption in the lungs.
Doctors have previously observed a serious form of lung damage in some heavy cannabis users known as “bong lung.” This condition is a type of emphysema, a disease in which the tiny air sacs in the lungs become damaged and lose their ability to exchange oxygen effectively.
The lung changes observed in the study may represent early warning signs of this type of damage. Although not everyone who smokes cannabis will develop severe lung disease, the findings suggest that long-term heavy use could increase the risk.
The research also confirmed that tobacco and cannabis affect the lungs in different ways. Tobacco is well known for causing inflammation, chronic bronchitis, and lung cancer. Cannabis smoke, on the other hand, appears to cause changes in lung size and airflow resistance.
Professor Hancox explained that people who smoke both cannabis and tobacco may be exposed to the harmful effects of both substances at the same time. This combination could lead to more severe damage to the lungs than using either substance alone.
Scientists are still trying to understand exactly why cannabis affects the lungs differently from tobacco. It may be related to the way cannabis smoke is inhaled, the chemical compounds in the smoke, or the frequency of use. More research will be needed to answer these questions.
The study is especially important now because many countries are changing their laws about cannabis. As cannabis becomes more available and socially accepted, understanding its health effects becomes even more important.
Public health experts say that clear scientific evidence can help doctors give better advice to patients and help governments create informed policies about cannabis use.
For people who care about their lung health, the findings serve as an important reminder that inhaling smoke of any kind can have consequences for the respiratory system. While some people believe cannabis smoke is safer than tobacco smoke, this research suggests that it still carries significant risks.
By continuing to follow participants over time, the Dunedin Study will help scientists learn even more about how lifestyle choices influence health across a lifetime.
If you care about lung health, please read studies about marijuana’s effects on lung health, and why some non-smokers get lung disease and some heavy smokers do not.
For more information about health, please see recent studies that olive oil may help you live longer, and vitamin D could help lower the risk of autoimmune diseases.
The study was published in the American Journal of Respiratory and Critical Care Medicine.
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